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LeetCode

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Solutions

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# Solution Tags Difficulty Remark
0001 Two Sum Array,Hash Table Easy
0002 Add Two Numbers Recursion,Linked List,Math Medium
0003 Longest Substring Without Repeating Characters Hash Table,String,Sliding Window Medium
0004 Median of Two Sorted Arrays Array,Binary Search,Divide and Conquer Hard
0005 Longest Palindromic Substring String,Dynamic Programming Medium
0006 Zigzag Conversion String Medium
0007 Reverse Integer Math Medium
0008 String to Integer (atoi) String Medium
0009 Palindrome Number Math Easy
0010 Regular Expression Matching Recursion,String,Dynamic Programming Hard
0011 Container With Most Water Greedy,Array,Two Pointers Medium
0012 Integer to Roman Hash Table,Math,String Medium
0013 Roman to Integer Hash Table,Math,String Easy
0014 Longest Common Prefix String Easy
0015 3Sum Array,Two Pointers,Sorting Medium
0016 3Sum Closest Array,Two Pointers,Sorting Medium
0017 Letter Combinations of a Phone Number Hash Table,String,Backtracking Medium
0018 4Sum Array,Two Pointers,Sorting Medium
0019 Remove Nth Node From End of List Linked List,Two Pointers Medium
0020 Valid Parentheses Stack,String Easy
0021 Merge Two Sorted Lists Recursion,Linked List Easy
0022 Generate Parentheses String,Dynamic Programming,Backtracking Medium
0023 Merge k Sorted Lists Linked List,Divide and Conquer,Heap (Priority Queue),Merge Sort Hard
0024 Swap Nodes in Pairs Recursion,Linked List Medium
0025 Reverse Nodes in k-Group Recursion,Linked List Hard
0026 Remove Duplicates from Sorted Array Array,Two Pointers Easy
0027 Remove Element Array,Two Pointers Easy
0028 Implement strStr() Two Pointers,String,String Matching Easy
0029 Divide Two Integers Bit Manipulation,Math Medium
0030 Substring with Concatenation of All Words Hash Table,String,Sliding Window Hard
0031 Next Permutation Array,Two Pointers Medium
0032 Longest Valid Parentheses Stack,String,Dynamic Programming Hard
0033 Search in Rotated Sorted Array Array,Binary Search Medium
0034 Find First and Last Position of Element in Sorted Array Array,Binary Search Medium
0035 Search Insert Position Array,Binary Search Easy
0036 Valid Sudoku Array,Hash Table,Matrix Medium
0037 Sudoku Solver Array,Backtracking,Matrix Hard
0038 Count and Say String Medium
0039 Combination Sum Array,Backtracking Medium
0040 Combination Sum II Array,Backtracking Medium
0041 First Missing Positive Array,Hash Table Hard
0042 Trapping Rain Water Stack,Array,Two Pointers,Dynamic Programming,Monotonic Stack Hard
0043 Multiply Strings Math,String,Simulation Medium
0044 Wildcard Matching Greedy,Recursion,String,Dynamic Programming Hard
0045 Jump Game II Greedy,Array,Dynamic Programming Medium
0046 Permutations Array,Backtracking Medium
0047 Permutations II Array,Backtracking Medium
0048 Rotate Image Array,Math,Matrix Medium
0049 Group Anagrams Array,Hash Table,String,Sorting Medium
0050 Pow(x, n) Recursion,Math Medium
0051 N-Queens Array,Backtracking Hard
0052 N-Queens II Backtracking Hard
0053 Maximum Subarray Array,Divide and Conquer,Dynamic Programming Easy
0054 Spiral Matrix Array,Matrix,Simulation Medium
0055 Jump Game Greedy,Array,Dynamic Programming Medium
0056 Merge Intervals Array,Sorting Medium
0057 Insert Interval Array Medium
0058 Length of Last Word String Easy
0059 Spiral Matrix II Array,Matrix,Simulation Medium
0060 Permutation Sequence Recursion,Math Hard
0061 Rotate List Linked List,Two Pointers Medium
0062 Unique Paths Math,Dynamic Programming,Combinatorics Medium
0063 Unique Paths II Array,Dynamic Programming,Matrix Medium
0064 Minimum Path Sum Array,Dynamic Programming,Matrix Medium
0065 Valid Number String Hard
0066 Plus One Array,Math Easy
0067 Add Binary Bit Manipulation,Math,String,Simulation Easy
0068 Text Justification Array,String,Simulation Hard
0069 Sqrt(x) Math,Binary Search Easy
0070 Climbing Stairs Memoization,Math,Dynamic Programming Easy
0071 Simplify Path Stack,String Medium
0072 Edit Distance String,Dynamic Programming Hard
0073 Set Matrix Zeroes Array,Hash Table,Matrix Medium
0074 Search a 2D Matrix Array,Binary Search,Matrix Medium
0075 Sort Colors Array,Two Pointers,Sorting Medium
0076 Minimum Window Substring Hash Table,String,Sliding Window Hard
0077 Combinations Backtracking Medium
0078 Subsets Bit Manipulation,Array,Backtracking Medium
0079 Word Search Array,Backtracking,Matrix Medium
0080 Remove Duplicates from Sorted Array II Array,Two Pointers Medium
0081 Search in Rotated Sorted Array II Array,Binary Search Medium
0082 Remove Duplicates from Sorted List II Linked List,Two Pointers Medium
0083 Remove Duplicates from Sorted List Linked List Easy
0084 Largest Rectangle in Histogram Stack,Array,Monotonic Stack Hard
0085 Maximal Rectangle Stack,Array,Dynamic Programming,Matrix,Monotonic Stack Hard
0086 Partition List Linked List,Two Pointers Medium
0087 Scramble String String,Dynamic Programming Hard
0088 Merge Sorted Array Array,Two Pointers,Sorting Easy
0089 Gray Code Bit Manipulation,Math,Backtracking Medium
0090 Subsets II Bit Manipulation,Array,Backtracking Medium
0091 Decode Ways String,Dynamic Programming Medium
0092 Reverse Linked List II Linked List Medium
0093 Restore IP Addresses String,Backtracking Medium
0094 Binary Tree Inorder Traversal Stack,Tree,Depth-First Search,Binary Tree Easy
0095 Unique Binary Search Trees II Tree,Binary Search Tree,Dynamic Programming,Backtracking,Binary Tree Medium
0096 Unique Binary Search Trees Tree,Binary Search Tree,Math,Dynamic Programming,Binary Tree Medium
0097 Interleaving String String,Dynamic Programming Medium
0098 Validate Binary Search Tree Tree,Depth-First Search,Binary Search Tree,Binary Tree Medium
0099 Recover Binary Search Tree Tree,Depth-First Search,Binary Search Tree,Binary Tree Medium
0100 Same Tree Tree,Depth-First Search,Breadth-First Search,Binary Tree Easy
0101 Symmetric Tree Tree,Depth-First Search,Breadth-First Search,Binary Tree Easy
0102 Binary Tree Level Order Traversal Tree,Breadth-First Search,Binary Tree Medium
0103 Binary Tree Zigzag Level Order Traversal Tree,Breadth-First Search,Binary Tree Medium
0104 Maximum Depth of Binary Tree Tree,Depth-First Search,Breadth-First Search,Binary Tree Easy
0105 Construct Binary Tree from Preorder and Inorder Traversal Tree,Array,Hash Table,Divide and Conquer,Binary Tree Medium
0106 Construct Binary Tree from Inorder and Postorder Traversal Tree,Array,Hash Table,Divide and Conquer,Binary Tree Medium
0107 Binary Tree Level Order Traversal II Tree,Breadth-First Search,Binary Tree Medium
0108 Convert Sorted Array to Binary Search Tree Tree,Binary Search Tree,Array,Divide and Conquer,Binary Tree Easy
0109 Convert Sorted List to Binary Search Tree Tree,Binary Search Tree,Linked List,Divide and Conquer,Binary Tree Medium
0110 Balanced Binary Tree Tree,Depth-First Search,Binary Tree Easy
0111 Minimum Depth of Binary Tree Tree,Depth-First Search,Breadth-First Search,Binary Tree Easy
0112 Path Sum Tree,Depth-First Search,Breadth-First Search,Binary Tree Easy
0113 Path Sum II Tree,Depth-First Search,Backtracking,Binary Tree Medium
0114 Flatten Binary Tree to Linked List Stack,Tree,Depth-First Search,Linked List,Binary Tree Medium
0115 Distinct Subsequences String,Dynamic Programming Hard
0116 Populating Next Right Pointers in Each Node Tree,Depth-First Search,Breadth-First Search,Linked List,Binary Tree Medium
0117 Populating Next Right Pointers in Each Node II Tree,Depth-First Search,Breadth-First Search,Linked List,Binary Tree Medium
0118 Pascal's Triangle Array,Dynamic Programming Easy
0119 Pascal's Triangle II Array,Dynamic Programming Easy
0120 Triangle Array,Dynamic Programming Medium
0121 Best Time to Buy and Sell Stock Array,Dynamic Programming Easy
0122 Best Time to Buy and Sell Stock II Greedy,Array,Dynamic Programming Medium
0123 Best Time to Buy and Sell Stock III Array,Dynamic Programming Hard
0124 Binary Tree Maximum Path Sum Tree,Depth-First Search,Dynamic Programming,Binary Tree Hard
0125 Valid Palindrome Two Pointers,String Easy
0126 Word Ladder II Breadth-First Search,Hash Table,String,Backtracking Hard
0127 Word Ladder Breadth-First Search,Hash Table,String Hard
0128 Longest Consecutive Sequence Union Find,Array,Hash Table Medium
0129 Sum Root to Leaf Numbers Tree,Depth-First Search,Binary Tree Medium
0130 Surrounded Regions Depth-First Search,Breadth-First Search,Union Find,Array,Matrix Medium
0131 Palindrome Partitioning String,Dynamic Programming,Backtracking Medium
0132 Palindrome Partitioning II String,Dynamic Programming Hard
0133 Clone Graph Depth-First Search,Breadth-First Search,Graph,Hash Table Medium
0134 Gas Station Greedy,Array Medium
0135 Candy Greedy,Array Hard
0136 Single Number Bit Manipulation,Array Easy
0137 Single Number II Bit Manipulation,Array Medium
0138 Copy List with Random Pointer Hash Table,Linked List Medium
0139 Word Break Trie,Memoization,Hash Table,String,Dynamic Programming Medium
0140 Word Break II Trie,Memoization,Hash Table,String,Dynamic Programming,Backtracking Hard
0141 Linked List Cycle Hash Table,Linked List,Two Pointers Easy
0142 Linked List Cycle II Hash Table,Linked List,Two Pointers Medium
0143 Reorder List Stack,Recursion,Linked List,Two Pointers Medium
0144 Binary Tree Preorder Traversal Stack,Tree,Depth-First Search,Binary Tree Easy
0145 Binary Tree Postorder Traversal Stack,Tree,Depth-First Search,Binary Tree Easy
0146 LRU Cache Design,Hash Table,Linked List,Doubly-Linked List Medium
0147 Insertion Sort List Linked List,Sorting Medium
0148 Sort List Linked List,Two Pointers,Divide and Conquer,Sorting,Merge Sort Medium
0149 Max Points on a Line Geometry,Array,Hash Table,Math Hard
0150 Evaluate Reverse Polish Notation Stack,Array,Math Medium
0151 Reverse Words in a String Two Pointers,String Medium
0152 Maximum Product Subarray Array,Dynamic Programming Medium
0153 Find Minimum in Rotated Sorted Array Array,Binary Search Medium
0154 Find Minimum in Rotated Sorted Array II Array,Binary Search Hard
0155 Min Stack Stack,Design Medium
0156 Binary Tree Upside Down Tree,Depth-First Search,Binary Tree Medium ๐Ÿ”’
0157 Read N Characters Given Read4 String,Interactive,Simulation Easy ๐Ÿ”’
0158 Read N Characters Given read4 II - Call Multiple Times String,Interactive,Simulation Hard ๐Ÿ”’
0159 Longest Substring with At Most Two Distinct Characters Hash Table,String,Sliding Window Medium ๐Ÿ”’
0160 Intersection of Two Linked Lists Hash Table,Linked List,Two Pointers Easy
0161 One Edit Distance Two Pointers,String Medium ๐Ÿ”’
0162 Find Peak Element Array,Binary Search Medium
0163 Missing Ranges Array Easy ๐Ÿ”’
0164 Maximum Gap Array,Bucket Sort,Radix Sort,Sorting Hard
0165 Compare Version Numbers Two Pointers,String Medium
0166 Fraction to Recurring Decimal Hash Table,Math,String Medium
0167 Two Sum II - Input Array Is Sorted Array,Two Pointers,Binary Search Medium
0168 Excel Sheet Column Title Math,String Easy
0169 Majority Element Array,Hash Table,Divide and Conquer,Counting,Sorting Easy
0170 Two Sum III - Data structure design Design,Array,Hash Table,Two Pointers,Data Stream Easy ๐Ÿ”’
0171 Excel Sheet Column Number Math,String Easy
0172 Factorial Trailing Zeroes Math Medium
0173 Binary Search Tree Iterator Stack,Tree,Design,Binary Search Tree,Binary Tree,Iterator Medium
0174 Dungeon Game Array,Dynamic Programming,Matrix Hard
0175 Combine Two Tables Database Easy
0176 Second Highest Salary Database Medium
0177 Nth Highest Salary Database Medium
0178 Rank Scores Database Medium
0179 Largest Number Greedy,String,Sorting Medium
0180 Consecutive Numbers Database Medium
0181 Employees Earning More Than Their Managers Database Easy
0182 Duplicate Emails Database Easy
0183 Customers Who Never Order Database Easy
0184 Department Highest Salary Database Medium
0185 Department Top Three Salaries Database Hard
0186 Reverse Words in a String II Two Pointers,String Medium ๐Ÿ”’
0187 Repeated DNA Sequences Bit Manipulation,Hash Table,String,Sliding Window,Hash Function,Rolling Hash Medium
0188 Best Time to Buy and Sell Stock IV Array,Dynamic Programming Hard
0189 Rotate Array Array,Math,Two Pointers Medium
0190 Reverse Bits Bit Manipulation,Divide and Conquer Easy
0191 Number of 1 Bits Bit Manipulation,Divide and Conquer Easy
0192 Word Frequency Shell Medium
0193 Valid Phone Numbers Shell Easy
0194 Transpose File Shell Medium
0195 Tenth Line Shell Easy
0196 Delete Duplicate Emails Database Easy
0197 Rising Temperature Database Easy
0198 House Robber Array,Dynamic Programming Medium
0199 Binary Tree Right Side View Tree,Depth-First Search,Breadth-First Search,Binary Tree Medium
0200 Number of Islands Depth-First Search,Breadth-First Search,Union Find,Array,Matrix Medium
0201 Bitwise AND of Numbers Range Bit Manipulation Medium
0202 Happy Number Hash Table,Math,Two Pointers Easy
0203 Remove Linked List Elements Recursion,Linked List Easy
0204 Count Primes Array,Math,Enumeration,Number Theory Medium
0205 Isomorphic Strings Hash Table,String Easy
0206 Reverse Linked List Recursion,Linked List Easy
0207 Course Schedule Depth-First Search,Breadth-First Search,Graph,Topological Sort Medium
0208 Implement Trie (Prefix Tree) Design,Trie,Hash Table,String Medium
0209 Minimum Size Subarray Sum Array,Binary Search,Prefix Sum,Sliding Window Medium
0210 Course Schedule II Depth-First Search,Breadth-First Search,Graph,Topological Sort Medium
0211 Design Add and Search Words Data Structure Depth-First Search,Design,Trie,String Medium
0212 Word Search II Trie,Array,String,Backtracking,Matrix Hard
0213 House Robber II Array,Dynamic Programming Medium
0214 Shortest Palindrome String,String Matching,Hash Function,Rolling Hash Hard
0215 Kth Largest Element in an Array Array,Divide and Conquer,Quickselect,Sorting,Heap (Priority Queue) Medium
0216 Combination Sum III Array,Backtracking Medium
0217 Contains Duplicate Array,Hash Table,Sorting Easy
0218 The Skyline Problem Binary Indexed Tree,Segment Tree,Array,Divide and Conquer,Ordered Set,Line Sweep,Heap (Priority Queue) Hard
0219 Contains Duplicate II Array,Hash Table,Sliding Window Easy
0220 Contains Duplicate III Array,Bucket Sort,Ordered Set,Sorting,Sliding Window Medium
0221 Maximal Square Array,Dynamic Programming,Matrix Medium
0222 Count Complete Tree Nodes Tree,Depth-First Search,Binary Search,Binary Tree Medium
0223 Rectangle Area Geometry,Math Medium
0224 Basic Calculator Stack,Recursion,Math,String Hard
0225 Implement Stack using Queues Stack,Design,Queue Easy
0226 Invert Binary Tree Tree,Depth-First Search,Breadth-First Search,Binary Tree Easy
0227 Basic Calculator II Stack,Math,String Medium
0228 Summary Ranges Array Easy
0229 Majority Element II Array,Hash Table,Counting,Sorting Medium
0230 Kth Smallest Element in a BST Tree,Depth-First Search,Binary Search Tree,Binary Tree Medium
0231 Power of Two Bit Manipulation,Recursion,Math Easy
0232 Implement Queue using Stacks Stack,Design,Queue Easy
0233 Number of Digit One Recursion,Math,Dynamic Programming Hard
0234 Palindrome Linked List Stack,Recursion,Linked List,Two Pointers Easy
0235 Lowest Common Ancestor of a Binary Search Tree Tree,Depth-First Search,Binary Search Tree,Binary Tree Easy
0236 Lowest Common Ancestor of a Binary Tree Tree,Depth-First Search,Binary Tree Medium
0237 Delete Node in a Linked List Linked List Easy
0238 Product of Array Except Self Array,Prefix Sum Medium
0239 Sliding Window Maximum Queue,Array,Sliding Window,Monotonic Queue,Heap (Priority Queue) Hard
0240 Search a 2D Matrix II Array,Binary Search,Divide and Conquer,Matrix Medium
0241 Different Ways to Add Parentheses Recursion,Memoization,Math,String,Dynamic Programming Medium
0242 Valid Anagram Hash Table,String,Sorting Easy
0243 Shortest Word Distance Array,String Easy ๐Ÿ”’
0244 Shortest Word Distance II Design,Array,Hash Table,Two Pointers,String Medium ๐Ÿ”’
0245 Shortest Word Distance III Array,String Medium ๐Ÿ”’
0246 Strobogrammatic Number Hash Table,Two Pointers,String Easy ๐Ÿ”’
0247 Strobogrammatic Number II Recursion,Array,String Medium ๐Ÿ”’
0248 Strobogrammatic Number III Recursion,Array,String Hard ๐Ÿ”’
0249 Group Shifted Strings Array,Hash Table,String Medium ๐Ÿ”’
0250 Count Univalue Subtrees Tree,Depth-First Search,Binary Tree Medium ๐Ÿ”’
0251 Flatten 2D Vector Design,Array,Two Pointers,Iterator Medium ๐Ÿ”’
0252 Meeting Rooms Array,Sorting Easy ๐Ÿ”’
0253 Meeting Rooms II Greedy,Array,Two Pointers,Sorting,Heap (Priority Queue) Medium ๐Ÿ”’
0254 Factor Combinations Array,Backtracking Medium ๐Ÿ”’
0255 Verify Preorder Sequence in Binary Search Tree Stack,Tree,Binary Search Tree,Recursion,Binary Tree,Monotonic Stack Medium ๐Ÿ”’
0256 Paint House Array,Dynamic Programming Medium ๐Ÿ”’
0257 Binary Tree Paths Tree,Depth-First Search,String,Backtracking,Binary Tree Easy
0258 Add Digits Math,Number Theory,Simulation Easy
0259 3Sum Smaller Array,Two Pointers,Binary Search,Sorting Medium ๐Ÿ”’
0260 Single Number III Bit Manipulation,Array Medium
0261 Graph Valid Tree Depth-First Search,Breadth-First Search,Union Find,Graph Medium ๐Ÿ”’
0262 Trips and Users Database Hard
0263 Ugly Number Math Easy
0264 Ugly Number II Hash Table,Math,Dynamic Programming,Heap (Priority Queue) Medium
0265 Paint House II Array,Dynamic Programming Hard ๐Ÿ”’
0266 Palindrome Permutation Bit Manipulation,Hash Table,String Easy ๐Ÿ”’
0267 Palindrome Permutation II Hash Table,String,Backtracking Medium ๐Ÿ”’
0268 Missing Number Bit Manipulation,Array,Hash Table,Math,Binary Search,Sorting Easy
0269 Alien Dictionary Depth-First Search,Breadth-First Search,Graph,Topological Sort,Array,String Hard ๐Ÿ”’
0270 Closest Binary Search Tree Value Tree,Depth-First Search,Binary Search Tree,Binary Search,Binary Tree Easy ๐Ÿ”’
0271 Encode and Decode Strings Design,Array,String Medium ๐Ÿ”’
0272 Closest Binary Search Tree Value II Stack,Tree,Depth-First Search,Binary Search Tree,Two Pointers,Binary Tree,Heap (Priority Queue) Hard ๐Ÿ”’
0273 Integer to English Words Recursion,Math,String Hard
0274 H-Index Array,Counting Sort,Sorting Medium
0275 H-Index II Array,Binary Search Medium
0276 Paint Fence Dynamic Programming Medium ๐Ÿ”’
0277 Find the Celebrity Greedy,Graph,Two Pointers,Interactive Medium ๐Ÿ”’
0278 First Bad Version Binary Search,Interactive Easy
0279 Perfect Squares Breadth-First Search,Math,Dynamic Programming Medium
0280 Wiggle Sort Greedy,Array,Sorting Medium ๐Ÿ”’
0281 Zigzag Iterator Design,Queue,Array,Iterator Medium ๐Ÿ”’
0282 Expression Add Operators Math,String,Backtracking Hard
0283 Move Zeroes Array,Two Pointers Easy
0284 Peeking Iterator Design,Array,Iterator Medium
0285 Inorder Successor in BST Tree,Depth-First Search,Binary Search Tree,Binary Tree Medium ๐Ÿ”’
0286 Walls and Gates Breadth-First Search,Array,Matrix Medium ๐Ÿ”’
0287 Find the Duplicate Number Bit Manipulation,Array,Two Pointers,Binary Search Medium
0288 Unique Word Abbreviation Design,Array,Hash Table,String Medium ๐Ÿ”’
0289 Game of Life Array,Matrix,Simulation Medium
0290 Word Pattern Hash Table,String Easy
0291 Word Pattern II Hash Table,String,Backtracking Medium ๐Ÿ”’
0292 Nim Game Brainteaser,Math,Game Theory Easy
0293 Flip Game String Easy ๐Ÿ”’
0294 Flip Game II Memoization,Math,Dynamic Programming,Backtracking,Game Theory Medium ๐Ÿ”’
0295 Find Median from Data Stream Design,Two Pointers,Data Stream,Sorting,Heap (Priority Queue) Hard
0296 Best Meeting Point Array,Math,Matrix,Sorting Hard ๐Ÿ”’
0297 Serialize and Deserialize Binary Tree Tree,Depth-First Search,Breadth-First Search,Design,String,Binary Tree Hard
0298 Binary Tree Longest Consecutive Sequence Tree,Depth-First Search,Binary Tree Medium ๐Ÿ”’
0299 Bulls and Cows Hash Table,String,Counting Medium
0300 Longest Increasing Subsequence Array,Binary Search,Dynamic Programming Medium
0301 Remove Invalid Parentheses Breadth-First Search,String,Backtracking Hard
0302 Smallest Rectangle Enclosing Black Pixels Depth-First Search,Breadth-First Search,Array,Binary Search,Matrix Hard ๐Ÿ”’
0303 Range Sum Query - Immutable Design,Array,Prefix Sum Easy
0304 Range Sum Query 2D - Immutable Design,Array,Matrix,Prefix Sum Medium
0305 Number of Islands II Union Find,Array Hard ๐Ÿ”’
0306 Additive Number String,Backtracking Medium
0307 Range Sum Query - Mutable Design,Binary Indexed Tree,Segment Tree,Array Medium
0308 Range Sum Query 2D - Mutable Design,Binary Indexed Tree,Segment Tree,Array,Matrix Hard ๐Ÿ”’
0309 Best Time to Buy and Sell Stock with Cooldown Array,Dynamic Programming Medium
0310 Minimum Height Trees Depth-First Search,Breadth-First Search,Graph,Topological Sort Medium
0311 Sparse Matrix Multiplication Array,Hash Table,Matrix Medium ๐Ÿ”’
0312 Burst Balloons Array,Dynamic Programming Hard
0313 Super Ugly Number Array,Math,Dynamic Programming Medium
0314 Binary Tree Vertical Order Traversal Tree,Depth-First Search,Breadth-First Search,Hash Table,Binary Tree Medium ๐Ÿ”’
0315 Count of Smaller Numbers After Self Binary Indexed Tree,Segment Tree,Array,Binary Search,Divide and Conquer,Ordered Set,Merge Sort Hard
0316 Remove Duplicate Letters Stack,Greedy,String,Monotonic Stack Medium
0317 Shortest Distance from All Buildings Breadth-First Search,Array,Matrix Hard ๐Ÿ”’
0318 Maximum Product of Word Lengths Bit Manipulation,Array,String Medium
0319 Bulb Switcher Brainteaser,Math Medium
0320 Generalized Abbreviation Bit Manipulation,String,Backtracking Medium ๐Ÿ”’
0321 Create Maximum Number Stack,Greedy,Monotonic Stack Hard
0322 Coin Change Breadth-First Search,Array,Dynamic Programming Medium
0323 Number of Connected Components in an Undirected Graph Depth-First Search,Breadth-First Search,Union Find,Graph Medium ๐Ÿ”’
0324 Wiggle Sort II Array,Divide and Conquer,Quickselect,Sorting Medium
0325 Maximum Size Subarray Sum Equals k Array,Hash Table Medium ๐Ÿ”’
0326 Power of Three Recursion,Math Easy
0327 Count of Range Sum Binary Indexed Tree,Segment Tree,Array,Binary Search,Divide and Conquer,Ordered Set,Merge Sort Hard
0328 Odd Even Linked List Linked List Medium
0329 Longest Increasing Path in a Matrix Depth-First Search,Breadth-First Search,Graph,Topological Sort,Memoization,Array,Dynamic Programming,Matrix Hard
0330 Patching Array Greedy,Array Hard
0331 Verify Preorder Serialization of a Binary Tree Stack,Tree,String,Binary Tree Medium
0332 Reconstruct Itinerary Depth-First Search,Graph,Eulerian Circuit Hard
0333 Largest BST Subtree Tree,Depth-First Search,Binary Search Tree,Dynamic Programming,Binary Tree Medium ๐Ÿ”’
0334 Increasing Triplet Subsequence Greedy,Array Medium
0335 Self Crossing Geometry,Array,Math Hard
0336 Palindrome Pairs Trie,Array,Hash Table,String Hard
0337 House Robber III Tree,Depth-First Search,Dynamic Programming,Binary Tree Medium
0338 Counting Bits Bit Manipulation,Dynamic Programming Easy
0339 Nested List Weight Sum Depth-First Search,Breadth-First Search Medium ๐Ÿ”’
0340 Longest Substring with At Most K Distinct Characters Hash Table,String,Sliding Window Medium ๐Ÿ”’
0341 Flatten Nested List Iterator Stack,Tree,Depth-First Search,Design,Queue,Iterator Medium
0342 Power of Four Bit Manipulation,Recursion,Math Easy
0343 Integer Break Math,Dynamic Programming Medium
0344 Reverse String Recursion,Two Pointers,String Easy
0345 Reverse Vowels of a String Two Pointers,String Easy
0346 Moving Average from Data Stream Design,Queue,Array,Data Stream Easy ๐Ÿ”’
0347 Top K Frequent Elements Array,Hash Table,Divide and Conquer,Bucket Sort,Counting,Quickselect,Sorting,Heap (Priority Queue) Medium
0348 Design Tic-Tac-Toe Design,Array,Hash Table,Matrix Medium ๐Ÿ”’
0349 Intersection of Two Arrays Array,Hash Table,Two Pointers,Binary Search,Sorting Easy
0350 Intersection of Two Arrays II Array,Hash Table,Two Pointers,Binary Search,Sorting Easy
0351 Android Unlock Patterns Dynamic Programming,Backtracking Medium ๐Ÿ”’
0352 Data Stream as Disjoint Intervals Design,Binary Search,Ordered Set Hard
0353 Design Snake Game Design,Queue,Array,Matrix Medium ๐Ÿ”’
0354 Russian Doll Envelopes Array,Binary Search,Dynamic Programming,Sorting Hard
0355 Design Twitter Design,Hash Table,Linked List,Heap (Priority Queue) Medium
0356 Line Reflection Array,Hash Table,Math Medium ๐Ÿ”’
0357 Count Numbers with Unique Digits Math,Dynamic Programming,Backtracking Medium
0358 Rearrange String k Distance Apart Greedy,Hash Table,String,Counting,Sorting,Heap (Priority Queue) Hard ๐Ÿ”’
0359 Logger Rate Limiter Design,Hash Table Easy ๐Ÿ”’
0360 Sort Transformed Array Array,Math,Two Pointers,Sorting Medium ๐Ÿ”’
0361 Bomb Enemy Array,Dynamic Programming,Matrix Medium ๐Ÿ”’
0362 Design Hit Counter Design,Queue,Array,Hash Table,Binary Search Medium ๐Ÿ”’
0363 Max Sum of Rectangle No Larger Than K Array,Binary Search,Dynamic Programming,Matrix,Ordered Set Hard
0364 Nested List Weight Sum II Stack,Depth-First Search,Breadth-First Search Medium ๐Ÿ”’
0365 Water and Jug Problem Depth-First Search,Breadth-First Search,Math Medium
0366 Find Leaves of Binary Tree Tree,Depth-First Search,Binary Tree Medium ๐Ÿ”’
0367 Valid Perfect Square Math,Binary Search Easy
0368 Largest Divisible Subset Array,Math,Dynamic Programming,Sorting Medium
0369 Plus One Linked List Linked List,Math Medium ๐Ÿ”’
0370 Range Addition Array,Prefix Sum Medium ๐Ÿ”’
0371 Sum of Two Integers Bit Manipulation,Math Medium
0372 Super Pow Math,Divide and Conquer Medium
0373 Find K Pairs with Smallest Sums Array,Heap (Priority Queue) Medium
0374 Guess Number Higher or Lower Binary Search,Interactive Easy
0375 Guess Number Higher or Lower II Math,Dynamic Programming,Game Theory Medium
0376 Wiggle Subsequence Greedy,Array,Dynamic Programming Medium
0377 Combination Sum IV Array,Dynamic Programming Medium
0378 Kth Smallest Element in a Sorted Matrix Array,Binary Search,Matrix,Sorting,Heap (Priority Queue) Medium
0379 Design Phone Directory Design,Queue,Array,Hash Table,Linked List Medium ๐Ÿ”’
0380 Insert Delete GetRandom O(1) Design,Array,Hash Table,Math,Randomized Medium
0381 Insert Delete GetRandom O(1) - Duplicates allowed Design,Array,Hash Table,Math,Randomized Hard
0382 Linked List Random Node Reservoir Sampling,Linked List,Math,Randomized Medium
0383 Ransom Note Hash Table,String,Counting Easy
0384 Shuffle an Array Array,Math,Randomized Medium
0385 Mini Parser Stack,Depth-First Search,String Medium
0386 Lexicographical Numbers Depth-First Search,Trie Medium
0387 First Unique Character in a String Queue,Hash Table,String,Counting Easy
0388 Longest Absolute File Path Stack,Depth-First Search,String Medium
0389 Find the Difference Bit Manipulation,Hash Table,String,Sorting Easy
0390 Elimination Game Recursion,Math Medium
0391 Perfect Rectangle Array,Line Sweep Hard
0392 Is Subsequence Two Pointers,String,Dynamic Programming Easy
0393 UTF-8 Validation Bit Manipulation,Array Medium
0394 Decode String Stack,Recursion,String Medium
0395 Longest Substring with At Least K Repeating Characters Hash Table,String,Divide and Conquer,Sliding Window Medium
0396 Rotate Function Array,Math,Dynamic Programming Medium
0397 Integer Replacement Greedy,Bit Manipulation,Memoization,Dynamic Programming Medium
0398 Random Pick Index Reservoir Sampling,Hash Table,Math,Randomized Medium
0399 Evaluate Division Depth-First Search,Breadth-First Search,Union Find,Graph,Array,Shortest Path Medium
0400 Nth Digit Math,Binary Search Medium
0401 Binary Watch Bit Manipulation,Backtracking Easy
0402 Remove K Digits Stack,Greedy,String,Monotonic Stack Medium
0403 Frog Jump Array,Dynamic Programming Hard
0404 Sum of Left Leaves Tree,Depth-First Search,Breadth-First Search,Binary Tree Easy
0405 Convert a Number to Hexadecimal Bit Manipulation,Math Easy
0406 Queue Reconstruction by Height Greedy,Binary Indexed Tree,Segment Tree,Array,Sorting Medium
0407 Trapping Rain Water II Breadth-First Search,Array,Matrix,Heap (Priority Queue) Hard
0408 Valid Word Abbreviation Two Pointers,String Easy ๐Ÿ”’
0409 Longest Palindrome Greedy,Hash Table,String Easy
0410 Split Array Largest Sum Greedy,Array,Binary Search,Dynamic Programming Hard
0411 Minimum Unique Word Abbreviation Bit Manipulation,String,Backtracking Hard ๐Ÿ”’
0412 Fizz Buzz Math,String,Simulation Easy
0413 Arithmetic Slices Array,Dynamic Programming Medium
0414 Third Maximum Number Array,Sorting Easy
0415 Add Strings Math,String,Simulation Easy
0416 Partition Equal Subset Sum Array,Dynamic Programming Medium
0417 Pacific Atlantic Water Flow Depth-First Search,Breadth-First Search,Array,Matrix Medium
0418 Sentence Screen Fitting String,Dynamic Programming,Simulation Medium ๐Ÿ”’
0419 Battleships in a Board Depth-First Search,Array,Matrix Medium
0420 Strong Password Checker Greedy,String,Heap (Priority Queue) Hard
0421 Maximum XOR of Two Numbers in an Array Bit Manipulation,Trie,Array,Hash Table Medium
0422 Valid Word Square Array,Matrix Easy ๐Ÿ”’
0423 Reconstruct Original Digits from English Hash Table,Math,String Medium
0424 Longest Repeating Character Replacement Hash Table,String,Sliding Window Medium
0425 Word Squares Trie,Array,String,Backtracking Hard ๐Ÿ”’
0426 Convert Binary Search Tree to Sorted Doubly Linked List Stack,Tree,Depth-First Search,Binary Search Tree,Linked List,Binary Tree,Doubly-Linked List Medium ๐Ÿ”’
0427 Construct Quad Tree Tree,Array,Divide and Conquer,Matrix Medium
0428 Serialize and Deserialize N-ary Tree Tree,Depth-First Search,Breadth-First Search,String Hard ๐Ÿ”’
0429 N-ary Tree Level Order Traversal Tree,Breadth-First Search Medium
0430 Flatten a Multilevel Doubly Linked List Depth-First Search,Linked List,Doubly-Linked List Medium
0431 Encode N-ary Tree to Binary Tree Tree,Depth-First Search,Breadth-First Search,Design,Binary Tree Hard ๐Ÿ”’
0432 All O`one Data Structure Design,Hash Table,Linked List,Doubly-Linked List Hard
0433 Minimum Genetic Mutation Breadth-First Search,Hash Table,String Medium
0434 Number of Segments in a String String Easy
0435 Non-overlapping Intervals Greedy,Array,Dynamic Programming,Sorting Medium
0436 Find Right Interval Array,Binary Search,Sorting Medium
0437 Path Sum III Tree,Depth-First Search,Binary Tree Medium
0438 Find All Anagrams in a String Hash Table,String,Sliding Window Medium
0439 Ternary Expression Parser Stack,Recursion,String Medium ๐Ÿ”’
0440 K-th Smallest in Lexicographical Order Trie Hard
0441 Arranging Coins Math,Binary Search Easy
0442 Find All Duplicates in an Array Array,Hash Table Medium
0443 String Compression Two Pointers,String Medium
0444 Sequence Reconstruction Graph,Topological Sort,Array Medium ๐Ÿ”’
0445 Add Two Numbers II Stack,Linked List,Math Medium
0446 Arithmetic Slices II - Subsequence Array,Dynamic Programming Hard
0447 Number of Boomerangs Array,Hash Table,Math Medium
0448 Find All Numbers Disappeared in an Array Array,Hash Table Easy
0449 Serialize and Deserialize BST Tree,Depth-First Search,Breadth-First Search,Design,Binary Search Tree,String,Binary Tree Medium
0450 Delete Node in a BST Tree,Binary Search Tree,Binary Tree Medium
0451 Sort Characters By Frequency Hash Table,String,Bucket Sort,Counting,Sorting,Heap (Priority Queue) Medium
0452 Minimum Number of Arrows to Burst Balloons Greedy,Array,Sorting Medium
0453 Minimum Moves to Equal Array Elements Array,Math Easy
0454 4Sum II Array,Hash Table Medium
0455 Assign Cookies Greedy,Array,Sorting Easy
0456 132 Pattern Stack,Array,Binary Search,Ordered Set,Monotonic Stack Medium
0457 Circular Array Loop Array,Hash Table,Two Pointers Medium
0458 Poor Pigs Math,Dynamic Programming,Combinatorics Hard
0459 Repeated Substring Pattern String,String Matching Easy
0460 LFU Cache Design,Hash Table,Linked List,Doubly-Linked List Hard
0461 Hamming Distance Bit Manipulation Easy
0462 Minimum Moves to Equal Array Elements II Array,Math,Sorting Medium
0463 Island Perimeter Depth-First Search,Breadth-First Search,Array,Matrix Easy
0464 Can I Win Bit Manipulation,Memoization,Math,Dynamic Programming,Bitmask,Game Theory Medium
0465 Optimal Account Balancing Bit Manipulation,Array,Dynamic Programming,Backtracking,Bitmask Hard ๐Ÿ”’
0466 Count The Repetitions String,Dynamic Programming Hard
0467 Unique Substrings in Wraparound String String,Dynamic Programming Medium
0468 Validate IP Address String Medium
0469 Convex Polygon Geometry,Math Medium ๐Ÿ”’
0470 Implement Rand10() Using Rand7() Math,Rejection Sampling,Probability and Statistics,Randomized Medium
0471 Encode String with Shortest Length String,Dynamic Programming Hard ๐Ÿ”’
0472 Concatenated Words Depth-First Search,Trie,Array,String,Dynamic Programming Hard
0473 Matchsticks to Square Bit Manipulation,Array,Dynamic Programming,Backtracking,Bitmask Medium
0474 Ones and Zeroes Array,String,Dynamic Programming Medium
0475 Heaters Array,Two Pointers,Binary Search,Sorting Medium
0476 Number Complement Bit Manipulation Easy
0477 Total Hamming Distance Bit Manipulation,Array,Math Medium
0478 Generate Random Point in a Circle Geometry,Math,Rejection Sampling,Randomized Medium
0479 Largest Palindrome Product Math Hard
0480 Sliding Window Median Array,Hash Table,Sliding Window,Heap (Priority Queue) Hard
0481 Magical String Two Pointers,String Medium
0482 License Key Formatting String Easy
0483 Smallest Good Base Math,Binary Search Hard
0484 Find Permutation Stack,Greedy,Array Medium ๐Ÿ”’
0485 Max Consecutive Ones Array Easy
0486 Predict the Winner Recursion,Array,Math,Dynamic Programming,Game Theory Medium
0487 Max Consecutive Ones II Array,Dynamic Programming,Sliding Window Medium ๐Ÿ”’
0488 Zuma Game Breadth-First Search,Memoization,String,Dynamic Programming Hard
0489 Robot Room Cleaner Backtracking,Interactive Hard ๐Ÿ”’
0490 The Maze Depth-First Search,Breadth-First Search,Graph Medium ๐Ÿ”’
0491 Increasing Subsequences Bit Manipulation,Array,Hash Table,Backtracking Medium
0492 Construct the Rectangle Math Easy
0493 Reverse Pairs Binary Indexed Tree,Segment Tree,Array,Binary Search,Divide and Conquer,Ordered Set,Merge Sort Hard
0494 Target Sum Array,Dynamic Programming,Backtracking Medium
0495 Teemo Attacking Array,Simulation Easy
0496 Next Greater Element I Stack,Array,Hash Table,Monotonic Stack Easy
0497 Random Point in Non-overlapping Rectangles Reservoir Sampling,Math,Binary Search,Ordered Set,Prefix Sum,Randomized Medium
0498 Diagonal Traverse Array,Matrix,Simulation Medium
0499 The Maze III Depth-First Search,Breadth-First Search,Graph,Shortest Path,Heap (Priority Queue) Hard ๐Ÿ”’
0500 Keyboard Row Array,Hash Table,String Easy
0501 Find Mode in Binary Search Tree Tree,Depth-First Search,Binary Search Tree,Binary Tree Easy
0502 IPO Greedy,Array,Sorting,Heap (Priority Queue) Hard
0503 Next Greater Element II Stack,Array,Monotonic Stack Medium
0504 Base 7 Math Easy
0505 The Maze II Depth-First Search,Breadth-First Search,Graph,Shortest Path,Heap (Priority Queue) Medium ๐Ÿ”’
0506 Relative Ranks Array,Sorting,Heap (Priority Queue) Easy
0507 Perfect Number Math Easy
0508 Most Frequent Subtree Sum Tree,Depth-First Search,Hash Table,Binary Tree Medium
0509 Fibonacci Number Recursion,Memoization,Math,Dynamic Programming Easy
0510 Inorder Successor in BST II Tree,Binary Search Tree,Binary Tree Medium ๐Ÿ”’
0511 Game Play Analysis I Database Easy
0512 Game Play Analysis II Database Easy ๐Ÿ”’
0513 Find Bottom Left Tree Value Tree,Depth-First Search,Breadth-First Search,Binary Tree Medium
0514 Freedom Trail Depth-First Search,Breadth-First Search,String,Dynamic Programming Hard
0515 Find Largest Value in Each Tree Row Tree,Depth-First Search,Breadth-First Search,Binary Tree Medium
0516 Longest Palindromic Subsequence String,Dynamic Programming Medium
0517 Super Washing Machines Greedy,Array Hard
0518 Coin Change 2 Array,Dynamic Programming Medium
0519 Random Flip Matrix Reservoir Sampling,Hash Table,Math,Randomized Medium
0520 Detect Capital String Easy
0521 Longest Uncommon Subsequence I String Easy
0522 Longest Uncommon Subsequence II Array,Hash Table,Two Pointers,String,Sorting Medium
0523 Continuous Subarray Sum Array,Hash Table,Math,Prefix Sum Medium
0524 Longest Word in Dictionary through Deleting Array,Two Pointers,String,Sorting Medium
0525 Contiguous Array Array,Hash Table,Prefix Sum Medium
0526 Beautiful Arrangement Bit Manipulation,Array,Dynamic Programming,Backtracking,Bitmask Medium
0527 Word Abbreviation Greedy,Trie,Array,String,Sorting Hard ๐Ÿ”’
0528 Random Pick with Weight Math,Binary Search,Prefix Sum,Randomized Medium
0529 Minesweeper Depth-First Search,Breadth-First Search,Array,Matrix Medium
0530 Minimum Absolute Difference in BST Tree,Depth-First Search,Breadth-First Search,Binary Search Tree,Binary Tree Easy
0531 Lonely Pixel I Array,Hash Table,Matrix Medium ๐Ÿ”’
0532 K-diff Pairs in an Array Array,Hash Table,Two Pointers,Binary Search,Sorting Medium
0533 Lonely Pixel II Array,Hash Table,Matrix Medium ๐Ÿ”’
0534 Game Play Analysis III Database Medium ๐Ÿ”’
0535 Encode and Decode TinyURL Design,Hash Table,String,Hash Function Medium
0536 Construct Binary Tree from String Tree,Depth-First Search,String,Binary Tree Medium ๐Ÿ”’
0537 Complex Number Multiplication Math,String,Simulation Medium
0538 Convert BST to Greater Tree Tree,Depth-First Search,Binary Search Tree,Binary Tree Medium
0539 Minimum Time Difference Array,Math,String,Sorting Medium
0540 Single Element in a Sorted Array Array,Binary Search Medium
0541 Reverse String II Two Pointers,String Easy
0542 01 Matrix Breadth-First Search,Array,Dynamic Programming,Matrix Medium
0543 Diameter of Binary Tree Tree,Depth-First Search,Binary Tree Easy
0544 Output Contest Matches Recursion,String,Simulation Medium ๐Ÿ”’
0545 Boundary of Binary Tree Tree,Depth-First Search,Binary Tree Medium ๐Ÿ”’
0546 Remove Boxes Memoization,Array,Dynamic Programming Hard
0547 Number of Provinces Depth-First Search,Breadth-First Search,Union Find,Graph Medium
0548 Split Array with Equal Sum Array,Prefix Sum Hard ๐Ÿ”’
0549 Binary Tree Longest Consecutive Sequence II Tree,Depth-First Search,Binary Tree Medium ๐Ÿ”’
0550 Game Play Analysis IV Database Medium ๐Ÿ”’
0551 Student Attendance Record I String Easy
0552 Student Attendance Record II Dynamic Programming Hard
0553 Optimal Division Array,Math,Dynamic Programming Medium
0554 Brick Wall Array,Hash Table Medium
0555 Split Concatenated Strings Greedy,Array,String Medium ๐Ÿ”’
0556 Next Greater Element III Math,Two Pointers,String Medium
0557 Reverse Words in a String III Two Pointers,String Easy
0558 Logical OR of Two Binary Grids Represented as Quad-Trees Tree,Divide and Conquer Medium
0559 Maximum Depth of N-ary Tree Tree,Depth-First Search,Breadth-First Search Easy
0560 Subarray Sum Equals K Array,Hash Table,Prefix Sum Medium
0561 Array Partition Greedy,Array,Counting Sort,Sorting Easy
0562 Longest Line of Consecutive One in Matrix Array,Dynamic Programming,Matrix Medium ๐Ÿ”’
0563 Binary Tree Tilt Tree,Depth-First Search,Binary Tree Easy
0564 Find the Closest Palindrome Math,String Hard
0565 Array Nesting Depth-First Search,Array Medium
0566 Reshape the Matrix Array,Matrix,Simulation Easy
0567 Permutation in String Hash Table,Two Pointers,String,Sliding Window Medium
0568 Maximum Vacation Days Array,Dynamic Programming,Matrix Hard ๐Ÿ”’
0569 Median Employee Salary Database Hard ๐Ÿ”’
0570 Managers with at Least 5 Direct Reports Database Medium ๐Ÿ”’
0571 Find Median Given Frequency of Numbers Database Hard ๐Ÿ”’
0572 Subtree of Another Tree Tree,Depth-First Search,Binary Tree,String Matching,Hash Function Easy
0573 Squirrel Simulation Array,Math Medium ๐Ÿ”’
0574 Winning Candidate Database Medium ๐Ÿ”’
0575 Distribute Candies Array,Hash Table Easy
0576 Out of Boundary Paths Dynamic Programming Medium
0577 Employee Bonus Database Easy ๐Ÿ”’
0578 Get Highest Answer Rate Question Database Medium ๐Ÿ”’
0579 Find Cumulative Salary of an Employee Database Hard ๐Ÿ”’
0580 Count Student Number in Departments Database Medium ๐Ÿ”’
0581 Shortest Unsorted Continuous Subarray Stack,Greedy,Array,Two Pointers,Sorting,Monotonic Stack Medium
0582 Kill Process Tree,Depth-First Search,Breadth-First Search,Array,Hash Table Medium ๐Ÿ”’
0583 Delete Operation for Two Strings String,Dynamic Programming Medium
0584 Find Customer Referee Database Easy
0585 Investments in 2016 Database Medium ๐Ÿ”’
0586 Customer Placing the Largest Number of Orders Database Easy
0587 Erect the Fence Geometry,Array,Math Hard
0588 Design In-Memory File System Design,Trie,Hash Table,String Hard ๐Ÿ”’
0589 N-ary Tree Preorder Traversal Stack,Tree,Depth-First Search Easy
0590 N-ary Tree Postorder Traversal Stack,Tree,Depth-First Search Easy
0591 Tag Validator Stack,String Hard
0592 Fraction Addition and Subtraction Math,String,Simulation Medium
0593 Valid Square Geometry,Math Medium
0594 Longest Harmonious Subsequence Array,Hash Table,Sorting Easy
0595 Big Countries Database Easy
0596 Classes More Than 5 Students Database Easy
0597 Friend Requests I Overall Acceptance Rate Database Easy ๐Ÿ”’
0598 Range Addition II Array,Math Easy
0599 Minimum Index Sum of Two Lists Array,Hash Table,String Easy
0600 Non-negative Integers without Consecutive Ones Dynamic Programming Hard
0601 Human Traffic of Stadium Database Hard
0602 Friend Requests II Who Has the Most Friends Database Medium ๐Ÿ”’
0603 Consecutive Available Seats Database Easy ๐Ÿ”’
0604 Design Compressed String Iterator Design,Array,Hash Table,String,Iterator Easy ๐Ÿ”’
0605 Can Place Flowers Greedy,Array Easy
0606 Construct String from Binary Tree Tree,Depth-First Search,String,Binary Tree Easy
0607 Sales Person Database Easy
0608 Tree Node Database Medium
0609 Find Duplicate File in System Array,Hash Table,String Medium
0610 Triangle Judgement Database Easy ๐Ÿ”’
0611 Valid Triangle Number Greedy,Array,Two Pointers,Binary Search,Sorting Medium
0612 Shortest Distance in a Plane Database Medium ๐Ÿ”’
0613 Shortest Distance in a Line Database Easy ๐Ÿ”’
0614 Second Degree Follower Database Medium ๐Ÿ”’
0615 Average Salary Departments VS Company Database Hard ๐Ÿ”’
0616 Add Bold Tag in String Trie,Array,Hash Table,String,String Matching Medium ๐Ÿ”’
0617 Merge Two Binary Trees Tree,Depth-First Search,Breadth-First Search,Binary Tree Easy
0618 Students Report By Geography Database Hard ๐Ÿ”’
0619 Biggest Single Number Database Easy ๐Ÿ”’
0620 Not Boring Movies Database Easy
0621 Task Scheduler Greedy,Array,Hash Table,Counting,Sorting,Heap (Priority Queue) Medium
0622 Design Circular Queue Design,Queue,Array,Linked List Medium
0623 Add One Row to Tree Tree,Depth-First Search,Breadth-First Search,Binary Tree Medium
0624 Maximum Distance in Arrays Greedy,Array Medium ๐Ÿ”’
0625 Minimum Factorization Greedy,Math Medium ๐Ÿ”’
0626 Exchange Seats Database Medium
0627 Swap Salary Database Easy
0628 Maximum Product of Three Numbers Array,Math,Sorting Easy
0629 K Inverse Pairs Array Dynamic Programming Hard
0630 Course Schedule III Greedy,Array,Heap (Priority Queue) Hard
0631 Design Excel Sum Formula Graph,Design,Topological Sort Hard ๐Ÿ”’
0632 Smallest Range Covering Elements from K Lists Greedy,Array,Hash Table,Sorting,Sliding Window,Heap (Priority Queue) Hard
0633 Sum of Square Numbers Math,Two Pointers,Binary Search Medium
0634 Find the Derangement of An Array Math,Dynamic Programming Medium ๐Ÿ”’
0635 Design Log Storage System Design,Hash Table,String,Ordered Set Medium ๐Ÿ”’
0636 Exclusive Time of Functions Stack,Array Medium
0637 Average of Levels in Binary Tree Tree,Depth-First Search,Breadth-First Search,Binary Tree Easy
0638 Shopping Offers Bit Manipulation,Memoization,Array,Dynamic Programming,Backtracking,Bitmask Medium
0639 Decode Ways II String,Dynamic Programming Hard
0640 Solve the Equation Math,String,Simulation Medium
0641 Design Circular Deque Design,Queue,Array,Linked List Medium
0642 Design Search Autocomplete System Design,Trie,String,Data Stream Hard ๐Ÿ”’
0643 Maximum Average Subarray I Array,Sliding Window Easy
0644 Maximum Average Subarray II Array,Binary Search Hard ๐Ÿ”’
0645 Set Mismatch Bit Manipulation,Array,Hash Table,Sorting Easy
0646 Maximum Length of Pair Chain Greedy,Array,Dynamic Programming,Sorting Medium
0647 Palindromic Substrings String,Dynamic Programming Medium
0648 Replace Words Trie,Array,Hash Table,String Medium
0649 Dota2 Senate Greedy,Queue,String Medium
0650 2 Keys Keyboard Math,Dynamic Programming Medium
0651 4 Keys Keyboard Math,Dynamic Programming Medium ๐Ÿ”’
0652 Find Duplicate Subtrees Tree,Depth-First Search,Hash Table,Binary Tree Medium
0653 Two Sum IV - Input is a BST Tree,Depth-First Search,Breadth-First Search,Binary Search Tree,Hash Table,Two Pointers,Binary Tree Easy
0654 Maximum Binary Tree Stack,Tree,Array,Divide and Conquer,Binary Tree,Monotonic Stack Medium
0655 Print Binary Tree Tree,Depth-First Search,Breadth-First Search,Binary Tree Medium
0656 Coin Path Array,Dynamic Programming Hard ๐Ÿ”’
0657 Robot Return to Origin String,Simulation Easy
0658 Find K Closest Elements Array,Two Pointers,Binary Search,Sorting,Heap (Priority Queue) Medium
0659 Split Array into Consecutive Subsequences Greedy,Array,Hash Table,Heap (Priority Queue) Medium
0660 Remove 9 Math Hard ๐Ÿ”’
0661 Image Smoother Array,Matrix Easy
0662 Maximum Width of Binary Tree Tree,Depth-First Search,Breadth-First Search,Binary Tree Medium
0663 Equal Tree Partition Tree,Depth-First Search,Binary Tree Medium ๐Ÿ”’
0664 Strange Printer String,Dynamic Programming Hard
0665 Non-decreasing Array Array Medium
0666 Path Sum IV Tree,Depth-First Search,Array,Binary Tree Medium ๐Ÿ”’
0667 Beautiful Arrangement II Array,Math Medium
0668 Kth Smallest Number in Multiplication Table Math,Binary Search Hard
0669 Trim a Binary Search Tree Tree,Depth-First Search,Binary Search Tree,Binary Tree Medium
0670 Maximum Swap Greedy,Math Medium
0671 Second Minimum Node In a Binary Tree Tree,Depth-First Search,Binary Tree Easy
0672 Bulb Switcher II Bit Manipulation,Depth-First Search,Breadth-First Search,Math Medium
0673 Number of Longest Increasing Subsequence Binary Indexed Tree,Segment Tree,Array,Dynamic Programming Medium
0674 Longest Continuous Increasing Subsequence Array Easy
0675 Cut Off Trees for Golf Event Breadth-First Search,Array,Matrix,Heap (Priority Queue) Hard
0676 Implement Magic Dictionary Design,Trie,Hash Table,String Medium
0677 Map Sum Pairs Design,Trie,Hash Table,String Medium
0678 Valid Parenthesis String Stack,Greedy,String,Dynamic Programming Medium
0679 24 Game Array,Math,Backtracking Hard
0680 Valid Palindrome II Greedy,Two Pointers,String Easy
0681 Next Closest Time String,Enumeration Medium ๐Ÿ”’
0682 Baseball Game Stack,Array,Simulation Easy
0683 K Empty Slots Binary Indexed Tree,Array,Ordered Set,Sliding Window Hard ๐Ÿ”’
0684 Redundant Connection Depth-First Search,Breadth-First Search,Union Find,Graph Medium
0685 Redundant Connection II Depth-First Search,Breadth-First Search,Union Find,Graph Hard
0686 Repeated String Match String,String Matching Medium
0687 Longest Univalue Path Tree,Depth-First Search,Binary Tree Medium
0688 Knight Probability in Chessboard Dynamic Programming Medium
0689 Maximum Sum of 3 Non-Overlapping Subarrays Array,Dynamic Programming Hard
0690 Employee Importance Depth-First Search,Breadth-First Search,Hash Table Medium
0691 Stickers to Spell Word Bit Manipulation,Array,String,Dynamic Programming,Backtracking,Bitmask Hard
0692 Top K Frequent Words Trie,Hash Table,String,Bucket Sort,Counting,Sorting,Heap (Priority Queue) Medium
0693 Binary Number with Alternating Bits Bit Manipulation Easy
0694 Number of Distinct Islands Depth-First Search,Breadth-First Search,Union Find,Hash Table,Hash Function Medium ๐Ÿ”’
0695 Max Area of Island Depth-First Search,Breadth-First Search,Union Find,Array,Matrix Medium
0696 Count Binary Substrings Two Pointers,String Easy
0697 Degree of an Array Array,Hash Table Easy
0698 Partition to K Equal Sum Subsets Bit Manipulation,Memoization,Array,Dynamic Programming,Backtracking,Bitmask Medium
0699 Falling Squares Segment Tree,Array,Ordered Set Hard
0700 Search in a Binary Search Tree Tree,Binary Search Tree,Binary Tree Easy
0701 Insert into a Binary Search Tree Tree,Binary Search Tree,Binary Tree Medium
0702 Search in a Sorted Array of Unknown Size Array,Binary Search,Interactive Medium ๐Ÿ”’
0703 Kth Largest Element in a Stream Tree,Design,Binary Search Tree,Binary Tree,Data Stream,Heap (Priority Queue) Easy
0704 Binary Search Array,Binary Search Easy
0705 Design HashSet Design,Array,Hash Table,Linked List,Hash Function Easy
0706 Design HashMap Design,Array,Hash Table,Linked List,Hash Function Easy
0707 Design Linked List Design,Linked List Medium
0708 Insert into a Sorted Circular Linked List Linked List Medium ๐Ÿ”’
0709 To Lower Case String Easy
0710 Random Pick with Blacklist Hash Table,Math,Binary Search,Sorting,Randomized Hard
0711 Number of Distinct Islands II Depth-First Search,Breadth-First Search,Union Find,Hash Table,Hash Function Hard ๐Ÿ”’
0712 Minimum ASCII Delete Sum for Two Strings String,Dynamic Programming Medium
0713 Subarray Product Less Than K Array,Sliding Window Medium
0714 Best Time to Buy and Sell Stock with Transaction Fee Greedy,Array,Dynamic Programming Medium
0715 Range Module Design,Segment Tree,Ordered Set Hard
0716 Max Stack Stack,Design,Linked List,Doubly-Linked List,Ordered Set Hard ๐Ÿ”’
0717 1-bit and 2-bit Characters Array Easy
0718 Maximum Length of Repeated Subarray Array,Binary Search,Dynamic Programming,Sliding Window,Hash Function,Rolling Hash Medium
0719 Find K-th Smallest Pair Distance Array,Two Pointers,Binary Search,Sorting Hard
0720 Longest Word in Dictionary Trie,Array,Hash Table,String,Sorting Easy
0721 Accounts Merge Depth-First Search,Breadth-First Search,Union Find,Array,String Medium
0722 Remove Comments Array,String Medium
0723 Candy Crush Array,Two Pointers,Matrix,Simulation Medium ๐Ÿ”’
0724 Find Pivot Index Array,Prefix Sum Easy
0725 Split Linked List in Parts Linked List Medium
0726 Number of Atoms Stack,Hash Table,String,Sorting Hard
0727 Minimum Window Subsequence String,Dynamic Programming,Sliding Window Hard ๐Ÿ”’
0728 Self Dividing Numbers Math Easy
0729 My Calendar I Design,Segment Tree,Binary Search,Ordered Set Medium
0730 Count Different Palindromic Subsequences String,Dynamic Programming Hard
0731 My Calendar II Design,Segment Tree,Binary Search,Ordered Set Medium
0732 My Calendar III Design,Segment Tree,Binary Search,Ordered Set Hard
0733 Flood Fill Depth-First Search,Breadth-First Search,Array,Matrix Easy
0734 Sentence Similarity Array,Hash Table,String Easy ๐Ÿ”’
0735 Asteroid Collision Stack,Array Medium
0736 Parse Lisp Expression Stack,Recursion,Hash Table,String Hard
0737 Sentence Similarity II Depth-First Search,Breadth-First Search,Union Find,Array,Hash Table,String Medium ๐Ÿ”’
0738 Monotone Increasing Digits Greedy,Math Medium
0739 Daily Temperatures Stack,Array,Monotonic Stack Medium
0740 Delete and Earn Array,Hash Table,Dynamic Programming Medium
0741 Cherry Pickup Array,Dynamic Programming,Matrix Hard
0742 Closest Leaf in a Binary Tree Tree,Depth-First Search,Breadth-First Search,Binary Tree Medium ๐Ÿ”’
0743 Network Delay Time Depth-First Search,Breadth-First Search,Graph,Shortest Path,Heap (Priority Queue) Medium
0744 Find Smallest Letter Greater Than Target Array,Binary Search Easy
0745 Prefix and Suffix Search Design,Trie,String Hard
0746 Min Cost Climbing Stairs Array,Dynamic Programming Easy
0747 Largest Number At Least Twice of Others Array,Sorting Easy
0748 Shortest Completing Word Array,Hash Table,String Easy
0749 Contain Virus Depth-First Search,Breadth-First Search,Array,Matrix,Simulation Hard
0750 Number Of Corner Rectangles Array,Math,Dynamic Programming,Matrix Medium ๐Ÿ”’
0751 IP to CIDR Bit Manipulation,String Medium ๐Ÿ”’
0752 Open the Lock Breadth-First Search,Array,Hash Table,String Medium
0753 Cracking the Safe Depth-First Search,Graph,Eulerian Circuit Hard
0754 Reach a Number Math,Binary Search Medium
0755 Pour Water Array,Simulation Medium ๐Ÿ”’
0756 Pyramid Transition Matrix Bit Manipulation,Depth-First Search,Breadth-First Search Medium
0757 Set Intersection Size At Least Two Greedy,Array,Sorting Hard
0758 Bold Words in String Trie,Array,Hash Table,String,String Matching Medium ๐Ÿ”’
0759 Employee Free Time Array,Sorting,Heap (Priority Queue) Hard ๐Ÿ”’
0760 Find Anagram Mappings Array,Hash Table Easy ๐Ÿ”’
0761 Special Binary String Recursion,String Hard
0762 Prime Number of Set Bits in Binary Representation Bit Manipulation,Math Easy
0763 Partition Labels Greedy,Hash Table,Two Pointers,String Medium
0764 Largest Plus Sign Array,Dynamic Programming Medium
0765 Couples Holding Hands Greedy,Depth-First Search,Breadth-First Search,Union Find,Graph Hard
0766 Toeplitz Matrix Array,Matrix Easy
0767 Reorganize String Greedy,Hash Table,String,Counting,Sorting,Heap (Priority Queue) Medium
0768 Max Chunks To Make Sorted II Stack,Greedy,Array,Sorting,Monotonic Stack Hard
0769 Max Chunks To Make Sorted Stack,Greedy,Array,Sorting,Monotonic Stack Medium
0770 Basic Calculator IV Stack,Recursion,Hash Table,Math,String Hard
0771 Jewels and Stones Hash Table,String Easy
0772 Basic Calculator III Stack,Recursion,Math,String Hard ๐Ÿ”’
0773 Sliding Puzzle Breadth-First Search,Array,Matrix Hard
0774 Minimize Max Distance to Gas Station Array,Binary Search Hard ๐Ÿ”’
0775 Global and Local Inversions Array,Math Medium
0776 Split BST Tree,Binary Search Tree,Recursion,Binary Tree Medium ๐Ÿ”’
0777 Swap Adjacent in LR String Two Pointers,String Medium
0778 Swim in Rising Water Depth-First Search,Breadth-First Search,Union Find,Array,Binary Search,Matrix,Heap (Priority Queue) Hard
0779 K-th Symbol in Grammar Bit Manipulation,Recursion,Math Medium
0780 Reaching Points Math Hard
0781 Rabbits in Forest Greedy,Array,Hash Table,Math Medium
0782 Transform to Chessboard Bit Manipulation,Array,Math,Matrix Hard
0783 Minimum Distance Between BST Nodes Tree,Depth-First Search,Breadth-First Search,Binary Search Tree,Binary Tree Easy
0784 Letter Case Permutation Bit Manipulation,String,Backtracking Medium
0785 Is Graph Bipartite Depth-First Search,Breadth-First Search,Union Find,Graph Medium
0786 K-th Smallest Prime Fraction Array,Binary Search,Sorting,Heap (Priority Queue) Medium
0787 Cheapest Flights Within K Stops Depth-First Search,Breadth-First Search,Graph,Dynamic Programming,Shortest Path,Heap (Priority Queue) Medium
0788 Rotated Digits Math,Dynamic Programming Medium
0789 Escape The Ghosts Array,Math Medium
0790 Domino and Tromino Tiling Dynamic Programming Medium
0791 Custom Sort String Hash Table,String,Sorting Medium
0792 Number of Matching Subsequences Trie,Hash Table,String,Sorting Medium
0793 Preimage Size of Factorial Zeroes Function Math,Binary Search Hard
0794 Valid Tic-Tac-Toe State Array,String Medium
0795 Number of Subarrays with Bounded Maximum Array,Two Pointers Medium
0796 Rotate String String,String Matching Easy
0797 All Paths From Source to Target Depth-First Search,Breadth-First Search,Graph,Backtracking Medium
0798 Smallest Rotation with Highest Score Array,Prefix Sum Hard
0799 Champagne Tower Dynamic Programming Medium
0800 Similar RGB Color Math,String,Enumeration Easy ๐Ÿ”’
0801 Minimum Swaps To Make Sequences Increasing Array,Dynamic Programming Hard
0802 Find Eventual Safe States Depth-First Search,Breadth-First Search,Graph,Topological Sort Medium
0803 Bricks Falling When Hit Union Find,Array,Matrix Hard
0804 Unique Morse Code Words Array,Hash Table,String Easy
0805 Split Array With Same Average Bit Manipulation,Array,Math,Dynamic Programming,Bitmask Hard
0806 Number of Lines To Write String Array,String Easy
0807 Max Increase to Keep City Skyline Greedy,Array,Matrix Medium
0808 Soup Servings Math,Dynamic Programming,Probability and Statistics Medium
0809 Expressive Words Array,Two Pointers,String Medium
0810 Chalkboard XOR Game Bit Manipulation,Brainteaser,Array,Math,Game Theory Hard
0811 Subdomain Visit Count Array,Hash Table,String,Counting Medium
0812 Largest Triangle Area Geometry,Array,Math Easy
0813 Largest Sum of Averages Array,Dynamic Programming Medium
0814 Binary Tree Pruning Tree,Depth-First Search,Binary Tree Medium
0815 Bus Routes Breadth-First Search,Array,Hash Table Hard
0816 Ambiguous Coordinates String,Backtracking Medium
0817 Linked List Components Hash Table,Linked List Medium
0818 Race Car Dynamic Programming Hard
0819 Most Common Word Hash Table,String,Counting Easy
0820 Short Encoding of Words Trie,Array,Hash Table,String Medium
0821 Shortest Distance to a Character Array,Two Pointers,String Easy
0822 Card Flipping Game Array,Hash Table Medium
0823 Binary Trees With Factors Array,Hash Table,Dynamic Programming Medium
0824 Goat Latin String Easy
0825 Friends Of Appropriate Ages Array,Two Pointers,Binary Search,Sorting Medium
0826 Most Profit Assigning Work Greedy,Array,Two Pointers,Binary Search,Sorting Medium
0827 Making A Large Island Depth-First Search,Breadth-First Search,Union Find,Array,Matrix Hard
0828 Count Unique Characters of All Substrings of a Given String Hash Table,String,Dynamic Programming Hard Weekly Contest 83
0829 Consecutive Numbers Sum Math,Enumeration Hard Weekly Contest 83
0830 Positions of Large Groups String Easy Weekly Contest 83
0831 Masking Personal Information String Medium Weekly Contest 83
0832 Flipping an Image Array,Two Pointers,Matrix,Simulation Easy Weekly Contest 84
0833 Find And Replace in String Array,String,Sorting Medium Weekly Contest 84
0834 Sum of Distances in Tree Tree,Depth-First Search,Graph,Dynamic Programming Hard Weekly Contest 84
0835 Image Overlap Array,Matrix Medium Weekly Contest 84
0836 Rectangle Overlap Geometry,Math Easy Weekly Contest 85
0837 New 21 Game Math,Dynamic Programming,Sliding Window,Probability and Statistics Medium Weekly Contest 85
0838 Push Dominoes Two Pointers,String,Dynamic Programming Medium Weekly Contest 85
0839 Similar String Groups Depth-First Search,Breadth-First Search,Union Find,Array,String Hard Weekly Contest 85
0840 Magic Squares In Grid Array,Math,Matrix Medium Weekly Contest 86
0841 Keys and Rooms Depth-First Search,Breadth-First Search,Graph Medium Weekly Contest 86
0842 Split Array into Fibonacci Sequence String,Backtracking Medium Weekly Contest 86
0843 Guess the Word Array,Math,String,Game Theory,Interactive Hard Weekly Contest 86
0844 Backspace String Compare Stack,Two Pointers,String,Simulation Easy Weekly Contest 87
0845 Longest Mountain in Array Array,Two Pointers,Dynamic Programming,Enumeration Medium Weekly Contest 87
0846 Hand of Straights Greedy,Array,Hash Table,Sorting Medium Weekly Contest 87
0847 Shortest Path Visiting All Nodes Bit Manipulation,Breadth-First Search,Graph,Dynamic Programming,Bitmask Hard Weekly Contest 87
0848 Shifting Letters Array,String Medium Weekly Contest 88
0849 Maximize Distance to Closest Person Array Medium Weekly Contest 88
0850 Rectangle Area II Segment Tree,Array,Ordered Set,Line Sweep Hard Weekly Contest 88
0851 Loud and Rich Depth-First Search,Graph,Topological Sort,Array Medium Weekly Contest 88
0852 Peak Index in a Mountain Array Array,Binary Search Medium Weekly Contest 89
0853 Car Fleet Stack,Array,Sorting,Monotonic Stack Medium Weekly Contest 89
0854 K-Similar Strings Breadth-First Search,String Hard Weekly Contest 89
0855 Exam Room Design,Ordered Set Medium Weekly Contest 89
0856 Score of Parentheses Stack,String Medium Weekly Contest 90
0857 Minimum Cost to Hire K Workers Greedy,Array,Sorting,Heap (Priority Queue) Hard Weekly Contest 90
0858 Mirror Reflection Geometry,Math Medium Weekly Contest 90
0859 Buddy Strings Hash Table,String Easy Weekly Contest 90
0860 Lemonade Change Greedy,Array Easy Weekly Contest 91
0861 Score After Flipping Matrix Greedy,Bit Manipulation,Array,Matrix Medium Weekly Contest 91
0862 Shortest Subarray with Sum at Least K Queue,Array,Binary Search,Prefix Sum,Sliding Window,Monotonic Queue,Heap (Priority Queue) Hard Weekly Contest 91
0863 All Nodes Distance K in Binary Tree Tree,Depth-First Search,Breadth-First Search,Binary Tree Medium Weekly Contest 91
0864 Shortest Path to Get All Keys Bit Manipulation,Breadth-First Search Hard Weekly Contest 92
0865 Smallest Subtree with all the Deepest Nodes Tree,Depth-First Search,Breadth-First Search,Hash Table,Binary Tree Medium Weekly Contest 92
0866 Prime Palindrome Math Medium Weekly Contest 92
0867 Transpose Matrix Array,Matrix,Simulation Easy Weekly Contest 92
0868 Binary Gap Bit Manipulation Easy Weekly Contest 93
0869 Reordered Power of 2 Math,Counting,Enumeration,Sorting Medium Weekly Contest 93
0870 Advantage Shuffle Greedy,Array,Sorting Medium Weekly Contest 93
0871 Minimum Number of Refueling Stops Greedy,Array,Dynamic Programming,Heap (Priority Queue) Hard Weekly Contest 93
0872 Leaf-Similar Trees Tree,Depth-First Search,Binary Tree Easy Weekly Contest 94
0873 Length of Longest Fibonacci Subsequence Array,Hash Table,Dynamic Programming Medium Weekly Contest 94
0874 Walking Robot Simulation Array,Simulation Medium Weekly Contest 94
0875 Koko Eating Bananas Array,Binary Search Medium Weekly Contest 94
0876 Middle of the Linked List Linked List,Two Pointers Easy Weekly Contest 95
0877 Stone Game Array,Math,Dynamic Programming,Game Theory Medium Weekly Contest 95
0878 Nth Magical Number Math,Binary Search Hard Weekly Contest 95
0879 Profitable Schemes Array,Dynamic Programming Hard Weekly Contest 95
0880 Decoded String at Index Stack,String Medium Weekly Contest 96
0881 Boats to Save People Greedy,Array,Two Pointers,Sorting Medium Weekly Contest 96
0882 Reachable Nodes In Subdivided Graph Graph,Shortest Path,Heap (Priority Queue) Hard Weekly Contest 96
0883 Projection Area of 3D Shapes Geometry,Array,Math,Matrix Easy Weekly Contest 96
0884 Uncommon Words from Two Sentences Hash Table,String Easy Weekly Contest 97
0885 Spiral Matrix III Array,Matrix,Simulation Medium Weekly Contest 97
0886 Possible Bipartition Depth-First Search,Breadth-First Search,Union Find,Graph Medium Weekly Contest 97
0887 Super Egg Drop Math,Binary Search,Dynamic Programming Hard Weekly Contest 97
0888 Fair Candy Swap Array,Hash Table,Binary Search,Sorting Easy Weekly Contest 98
0889 Construct Binary Tree from Preorder and Postorder Traversal Tree,Array,Hash Table,Divide and Conquer,Binary Tree Medium Weekly Contest 98
0890 Find and Replace Pattern Array,Hash Table,String Medium Weekly Contest 98
0891 Sum of Subsequence Widths Array,Math,Sorting Hard Weekly Contest 98
0892 Surface Area of 3D Shapes Geometry,Array,Math,Matrix Easy Weekly Contest 99
0893 Groups of Special-Equivalent Strings Array,Hash Table,String Medium Weekly Contest 99
0894 All Possible Full Binary Trees Tree,Recursion,Memoization,Dynamic Programming,Binary Tree Medium Weekly Contest 99
0895 Maximum Frequency Stack Stack,Design,Hash Table,Ordered Set Hard Weekly Contest 99
0896 Monotonic Array Array Easy Weekly Contest 100
0897 Increasing Order Search Tree Stack,Tree,Depth-First Search,Binary Search Tree,Binary Tree Easy Weekly Contest 100
0898 Bitwise ORs of Subarrays Bit Manipulation,Array,Dynamic Programming Medium Weekly Contest 100
0899 Orderly Queue Math,String,Sorting Hard Weekly Contest 100
0900 RLE Iterator Design,Array,Counting,Iterator Medium Weekly Contest 101
0901 Online Stock Span Stack,Design,Data Stream,Monotonic Stack Medium Weekly Contest 101
0902 Numbers At Most N Given Digit Set Array,Math,Binary Search,Dynamic Programming Hard Weekly Contest 101
0903 Valid Permutations for DI Sequence Dynamic Programming Hard Weekly Contest 101
0904 Fruit Into Baskets Array,Hash Table,Sliding Window Medium Weekly Contest 102
0905 Sort Array By Parity Array,Two Pointers,Sorting Easy Weekly Contest 102
0906 Super Palindromes Math,Enumeration Hard Weekly Contest 102
0907 Sum of Subarray Minimums Stack,Array,Dynamic Programming,Monotonic Stack Medium Weekly Contest 102
0908 Smallest Range I Array,Math Easy Weekly Contest 103
0909 Snakes and Ladders Breadth-First Search,Array,Matrix Medium Weekly Contest 103
0910 Smallest Range II Greedy,Array,Math,Sorting Medium Weekly Contest 103
0911 Online Election Design,Array,Hash Table,Binary Search Medium Weekly Contest 103
0912 Sort an Array Array,Divide and Conquer,Bucket Sort,Counting Sort,Radix Sort,Sorting,Heap (Priority Queue),Merge Sort Medium
0913 Cat and Mouse Graph,Topological Sort,Memoization,Math,Dynamic Programming,Game Theory Hard Weekly Contest 104
0914 X of a Kind in a Deck of Cards Array,Hash Table,Math,Counting,Number Theory Easy Weekly Contest 104
0915 Partition Array into Disjoint Intervals Array Medium Weekly Contest 104
0916 Word Subsets Array,Hash Table,String Medium Weekly Contest 104
0917 Reverse Only Letters Two Pointers,String Easy Weekly Contest 105
0918 Maximum Sum Circular Subarray Queue,Array,Divide and Conquer,Dynamic Programming,Monotonic Queue Medium Weekly Contest 105
0919 Complete Binary Tree Inserter Tree,Breadth-First Search,Design,Binary Tree Medium Weekly Contest 105
0920 Number of Music Playlists Math,Dynamic Programming,Combinatorics Hard Weekly Contest 105
0921 Minimum Add to Make Parentheses Valid Stack,Greedy,String Medium Weekly Contest 106
0922 Sort Array By Parity II Array,Two Pointers,Sorting Easy Weekly Contest 106
0923 3Sum With Multiplicity Array,Hash Table,Two Pointers,Counting,Sorting Medium Weekly Contest 106
0924 Minimize Malware Spread Depth-First Search,Breadth-First Search,Union Find,Array,Matrix Hard Weekly Contest 106
0925 Long Pressed Name Two Pointers,String Easy Weekly Contest 107
0926 Flip String to Monotone Increasing String,Dynamic Programming Medium Weekly Contest 107
0927 Three Equal Parts Array,Math Hard Weekly Contest 107
0928 Minimize Malware Spread II Depth-First Search,Breadth-First Search,Union Find,Array,Matrix Hard Weekly Contest 107
0929 Unique Email Addresses Array,Hash Table,String Easy Weekly Contest 108
0930 Binary Subarrays With Sum Array,Hash Table,Prefix Sum,Sliding Window Medium Weekly Contest 108
0931 Minimum Falling Path Sum Array,Dynamic Programming,Matrix Medium Weekly Contest 108
0932 Beautiful Array Array,Math,Divide and Conquer Medium Weekly Contest 108
0933 Number of Recent Calls Design,Queue,Data Stream Easy Weekly Contest 109
0934 Shortest Bridge Depth-First Search,Breadth-First Search,Array,Matrix Medium Weekly Contest 109
0935 Knight Dialer Dynamic Programming Medium Weekly Contest 109
0936 Stamping The Sequence Stack,Greedy,Queue,String Hard Weekly Contest 109
0937 Reorder Data in Log Files Array,String,Sorting Easy Weekly Contest 110
0938 Range Sum of BST Tree,Depth-First Search,Binary Search Tree,Binary Tree Easy Weekly Contest 110
0939 Minimum Area Rectangle Geometry,Array,Hash Table,Math,Sorting Medium Weekly Contest 110
0940 Distinct Subsequences II String,Dynamic Programming Hard Weekly Contest 110
0941 Valid Mountain Array Array Easy Weekly Contest 111
0942 DI String Match Greedy,Array,Math,Two Pointers,String Easy Weekly Contest 111
0943 Find the Shortest Superstring Bit Manipulation,Array,String,Dynamic Programming,Bitmask Hard Weekly Contest 111
0944 Delete Columns to Make Sorted Array,String Easy Weekly Contest 111
0945 Minimum Increment to Make Array Unique Greedy,Array,Counting,Sorting Medium Weekly Contest 112
0946 Validate Stack Sequences Stack,Array,Simulation Medium Weekly Contest 112
0947 Most Stones Removed with Same Row or Column Depth-First Search,Union Find,Graph Medium Weekly Contest 112
0948 Bag of Tokens Greedy,Array,Two Pointers,Sorting Medium Weekly Contest 112
0949 Largest Time for Given Digits String,Enumeration Medium Weekly Contest 113
0950 Reveal Cards In Increasing Order Queue,Array,Sorting,Simulation Medium Weekly Contest 113
0951 Flip Equivalent Binary Trees Tree,Depth-First Search,Binary Tree Medium Weekly Contest 113
0952 Largest Component Size by Common Factor Union Find,Array,Math Hard Weekly Contest 113
0953 Verifying an Alien Dictionary Array,Hash Table,String Easy Weekly Contest 114
0954 Array of Doubled Pairs Greedy,Array,Hash Table,Sorting Medium Weekly Contest 114
0955 Delete Columns to Make Sorted II Greedy,Array,String Medium Weekly Contest 114
0956 Tallest Billboard Array,Dynamic Programming Hard Weekly Contest 114
0957 Prison Cells After N Days Bit Manipulation,Array,Hash Table,Math Medium Weekly Contest 115
0958 Check Completeness of a Binary Tree Tree,Breadth-First Search,Binary Tree Medium Weekly Contest 115
0959 Regions Cut By Slashes Depth-First Search,Breadth-First Search,Union Find,Graph Medium Weekly Contest 115
0960 Delete Columns to Make Sorted III Array,String,Dynamic Programming Hard Weekly Contest 115
0961 N-Repeated Element in Size 2N Array Array,Hash Table Easy Weekly Contest 116
0962 Maximum Width Ramp Stack,Array,Monotonic Stack Medium Weekly Contest 116
0963 Minimum Area Rectangle II Geometry,Array,Math Medium Weekly Contest 116
0964 Least Operators to Express Number Math,Dynamic Programming Hard Weekly Contest 116
0965 Univalued Binary Tree Tree,Depth-First Search,Breadth-First Search,Binary Tree Easy Weekly Contest 117
0966 Vowel Spellchecker Array,Hash Table,String Medium Weekly Contest 117
0967 Numbers With Same Consecutive Differences Breadth-First Search,Backtracking Medium Weekly Contest 117
0968 Binary Tree Cameras Tree,Depth-First Search,Dynamic Programming,Binary Tree Hard Weekly Contest 117
0969 Pancake Sorting Greedy,Array,Two Pointers,Sorting Medium Weekly Contest 118
0970 Powerful Integers Hash Table,Math Medium Weekly Contest 118
0971 Flip Binary Tree To Match Preorder Traversal Tree,Depth-First Search,Binary Tree Medium Weekly Contest 118
0972 Equal Rational Numbers Math,String Hard Weekly Contest 118
0973 K Closest Points to Origin Geometry,Array,Math,Divide and Conquer,Quickselect,Sorting,Heap (Priority Queue) Medium Weekly Contest 119
0974 Subarray Sums Divisible by K Array,Hash Table,Prefix Sum Medium Weekly Contest 119
0975 Odd Even Jump Stack,Array,Dynamic Programming,Ordered Set,Monotonic Stack Hard Weekly Contest 119
0976 Largest Perimeter Triangle Greedy,Array,Math,Sorting Easy Weekly Contest 119
0977 Squares of a Sorted Array Array,Two Pointers,Sorting Easy Weekly Contest 120
0978 Longest Turbulent Subarray Array,Dynamic Programming,Sliding Window Medium Weekly Contest 120
0979 Distribute Coins in Binary Tree Tree,Depth-First Search,Binary Tree Medium Weekly Contest 120
0980 Unique Paths III Bit Manipulation,Array,Backtracking,Matrix Hard Weekly Contest 120
0981 Time Based Key-Value Store Design,Hash Table,String,Binary Search Medium Weekly Contest 121
0982 Triples with Bitwise AND Equal To Zero Bit Manipulation,Array,Hash Table Hard Weekly Contest 121
0983 Minimum Cost For Tickets Array,Dynamic Programming Medium Weekly Contest 121
0984 String Without AAA or BBB Greedy,String Medium Weekly Contest 121
0985 Sum of Even Numbers After Queries Array,Simulation Medium Weekly Contest 122
0986 Interval List Intersections Array,Two Pointers Medium Weekly Contest 122
0987 Vertical Order Traversal of a Binary Tree Tree,Depth-First Search,Breadth-First Search,Hash Table,Binary Tree Hard Weekly Contest 122
0988 Smallest String Starting From Leaf Tree,Depth-First Search,String,Binary Tree Medium Weekly Contest 122
0989 Add to Array-Form of Integer Array,Math Easy Weekly Contest 123
0990 Satisfiability of Equality Equations Union Find,Graph,Array,String Medium Weekly Contest 123
0991 Broken Calculator Greedy,Math Medium Weekly Contest 123
0992 Subarrays with K Different Integers Array,Hash Table,Counting,Sliding Window Hard Weekly Contest 123
0993 Cousins in Binary Tree Tree,Depth-First Search,Breadth-First Search,Binary Tree Easy Weekly Contest 124
0994 Rotting Oranges Breadth-First Search,Array,Matrix Medium Weekly Contest 124
0995 Minimum Number of K Consecutive Bit Flips Bit Manipulation,Array,Prefix Sum,Sliding Window Hard Weekly Contest 124
0996 Number of Squareful Arrays Bit Manipulation,Array,Math,Dynamic Programming,Backtracking,Bitmask Hard Weekly Contest 124
0997 Find the Town Judge Graph,Array,Hash Table Easy Weekly Contest 125
0998 Maximum Binary Tree II Tree,Binary Tree Medium Weekly Contest 125
0999 Available Captures for Rook Array,Matrix,Simulation Easy Weekly Contest 125
1000 Minimum Cost to Merge Stones Array,Dynamic Programming Hard Weekly Contest 126
1001 Grid Illumination Array,Hash Table Hard Weekly Contest 125
1002 Find Common Characters Array,Hash Table,String Easy Weekly Contest 126
1003 Check If Word Is Valid After Substitutions Stack,String Medium Weekly Contest 126
1004 Max Consecutive Ones III Array,Binary Search,Prefix Sum,Sliding Window Medium Weekly Contest 126
1005 Maximize Sum Of Array After K Negations Greedy,Array,Sorting Easy Weekly Contest 127
1006 Clumsy Factorial Stack,Math,Simulation Medium Weekly Contest 127
1007 Minimum Domino Rotations For Equal Row Greedy,Array Medium Weekly Contest 127
1008 Construct Binary Search Tree from Preorder Traversal Stack,Tree,Binary Search Tree,Array,Binary Tree,Monotonic Stack Medium Weekly Contest 127
1009 Complement of Base 10 Integer Bit Manipulation Easy Weekly Contest 128
1010 Pairs of Songs With Total Durations Divisible by 60 Array,Hash Table,Counting Medium Weekly Contest 128
1011 Capacity To Ship Packages Within D Days Array,Binary Search Medium Weekly Contest 128
1012 Numbers With Repeated Digits Math,Dynamic Programming Hard Weekly Contest 128
1013 Partition Array Into Three Parts With Equal Sum Greedy,Array Easy Weekly Contest 129
1014 Best Sightseeing Pair Array,Dynamic Programming Medium Weekly Contest 129
1015 Smallest Integer Divisible by K Hash Table,Math Medium Weekly Contest 129
1016 Binary String With Substrings Representing 1 To N String Medium Weekly Contest 129
1017 Convert to Base -2 Math Medium Weekly Contest 130
1018 Binary Prefix Divisible By 5 Array Easy Weekly Contest 130
1019 Next Greater Node In Linked List Stack,Array,Linked List,Monotonic Stack Medium Weekly Contest 130
1020 Number of Enclaves Depth-First Search,Breadth-First Search,Union Find,Array,Matrix Medium Weekly Contest 130
1021 Remove Outermost Parentheses Stack,String Easy Weekly Contest 131
1022 Sum of Root To Leaf Binary Numbers Tree,Depth-First Search,Binary Tree Easy Weekly Contest 131
1023 Camelcase Matching Trie,Two Pointers,String,String Matching Medium Weekly Contest 131
1024 Video Stitching Greedy,Array,Dynamic Programming Medium Weekly Contest 131
1025 Divisor Game Brainteaser,Math,Dynamic Programming,Game Theory Easy Weekly Contest 132
1026 Maximum Difference Between Node and Ancestor Tree,Depth-First Search,Binary Tree Medium Weekly Contest 132
1027 Longest Arithmetic Subsequence Array,Hash Table,Binary Search,Dynamic Programming Medium Weekly Contest 132
1028 Recover a Tree From Preorder Traversal Tree,Depth-First Search,String,Binary Tree Hard Weekly Contest 132
1029 Two City Scheduling Greedy,Array,Sorting Medium Weekly Contest 133
1030 Matrix Cells in Distance Order Geometry,Array,Math,Matrix,Sorting Easy Weekly Contest 133
1031 Maximum Sum of Two Non-Overlapping Subarrays Array,Dynamic Programming,Sliding Window Medium Weekly Contest 133
1032 Stream of Characters Design,Trie,Array,String,Data Stream Hard Weekly Contest 133
1033 Moving Stones Until Consecutive Brainteaser,Math Medium Weekly Contest 134
1034 Coloring A Border Depth-First Search,Breadth-First Search,Array,Matrix Medium Weekly Contest 134
1035 Uncrossed Lines Array,Dynamic Programming Medium Weekly Contest 134
1036 Escape a Large Maze Depth-First Search,Breadth-First Search,Array,Hash Table Hard Weekly Contest 134
1037 Valid Boomerang Geometry,Array,Math Easy Weekly Contest 135
1038 Binary Search Tree to Greater Sum Tree Tree,Depth-First Search,Binary Search Tree,Binary Tree Medium Weekly Contest 135
1039 Minimum Score Triangulation of Polygon Array,Dynamic Programming Medium Weekly Contest 135
1040 Moving Stones Until Consecutive II Array,Math,Two Pointers,Sorting Medium Weekly Contest 135
1041 Robot Bounded In Circle Math,String,Simulation Medium Weekly Contest 136
1042 Flower Planting With No Adjacent Depth-First Search,Breadth-First Search,Graph Medium Weekly Contest 136
1043 Partition Array for Maximum Sum Array,Dynamic Programming Medium Weekly Contest 136
1044 Longest Duplicate Substring String,Binary Search,Suffix Array,Sliding Window,Hash Function,Rolling Hash Hard Weekly Contest 136
1045 Customers Who Bought All Products Database Medium ๐Ÿ”’
1046 Last Stone Weight Array,Heap (Priority Queue) Easy Weekly Contest 137
1047 Remove All Adjacent Duplicates In String Stack,String Easy Weekly Contest 137
1048 Longest String Chain Array,Hash Table,Two Pointers,String,Dynamic Programming Medium Weekly Contest 137
1049 Last Stone Weight II Array,Dynamic Programming Medium Weekly Contest 137
1050 Actors and Directors Who Cooperated At Least Three Times Database Easy
1051 Height Checker Array,Counting Sort,Sorting Easy Weekly Contest 138
1052 Grumpy Bookstore Owner Array,Sliding Window Medium Weekly Contest 138
1053 Previous Permutation With One Swap Greedy,Array Medium Weekly Contest 138
1054 Distant Barcodes Greedy,Array,Hash Table,Counting,Sorting,Heap (Priority Queue) Medium Weekly Contest 138
1055 Shortest Way to Form String Greedy,String,Dynamic Programming Medium ๐Ÿ”’
1056 Confusing Number Math Easy ๐Ÿ”’
1057 Campus Bikes Greedy,Array,Sorting Medium ๐Ÿ”’
1058 Minimize Rounding Error to Meet Target Greedy,Array,Math,String Medium ๐Ÿ”’
1059 All Paths from Source Lead to Destination Depth-First Search,Graph Medium ๐Ÿ”’
1060 Missing Element in Sorted Array Array,Binary Search Medium ๐Ÿ”’
1061 Lexicographically Smallest Equivalent String Union Find,String Medium ๐Ÿ”’
1062 Longest Repeating Substring String,Binary Search,Dynamic Programming,Suffix Array,Hash Function,Rolling Hash Medium ๐Ÿ”’
1063 Number of Valid Subarrays Stack,Array,Monotonic Stack Hard ๐Ÿ”’
1064 Fixed Point Array,Binary Search Easy ๐Ÿ”’
1065 Index Pairs of a String Trie,Array,String,Sorting Easy ๐Ÿ”’
1066 Campus Bikes II Bit Manipulation,Array,Dynamic Programming,Backtracking,Bitmask Medium ๐Ÿ”’
1067 Digit Count in Range Math,Dynamic Programming Hard ๐Ÿ”’
1068 Product Sales Analysis I Database Easy ๐Ÿ”’
1069 Product Sales Analysis II Database Easy ๐Ÿ”’
1070 Product Sales Analysis III Database Medium ๐Ÿ”’
1071 Greatest Common Divisor of Strings Math,String Easy Weekly Contest 139
1072 Flip Columns For Maximum Number of Equal Rows Array,Hash Table,Matrix Medium Weekly Contest 139
1073 Adding Two Negabinary Numbers Array,Math Medium Weekly Contest 139
1074 Number of Submatrices That Sum to Target Array,Hash Table,Matrix,Prefix Sum Hard Weekly Contest 139
1075 Project Employees I Database Easy ๐Ÿ”’
1076 Project Employees II Database Easy ๐Ÿ”’
1077 Project Employees III Database Medium ๐Ÿ”’
1078 Occurrences After Bigram String Easy Weekly Contest 140
1079 Letter Tile Possibilities String,Backtracking Medium Weekly Contest 140
1080 Insufficient Nodes in Root to Leaf Paths Tree,Depth-First Search,Binary Tree Medium Weekly Contest 140
1081 Smallest Subsequence of Distinct Characters Stack,Greedy,String,Monotonic Stack Medium Weekly Contest 140
1082 Sales Analysis I Database Easy ๐Ÿ”’
1083 Sales Analysis II Database Easy ๐Ÿ”’
1084 Sales Analysis III Database Easy
1085 Sum of Digits in the Minimum Number Array,Math Easy ๐Ÿ”’
1086 High Five Array,Hash Table,Sorting Easy ๐Ÿ”’
1087 Brace Expansion Breadth-First Search,String,Backtracking Medium ๐Ÿ”’
1088 Confusing Number II Math,Backtracking Hard ๐Ÿ”’
1089 Duplicate Zeros Array,Two Pointers Easy Weekly Contest 141
1090 Largest Values From Labels Greedy,Array,Hash Table,Counting,Sorting Medium Weekly Contest 141
1091 Shortest Path in Binary Matrix Breadth-First Search,Array,Matrix Medium Weekly Contest 141
1092 Shortest Common Supersequence String,Dynamic Programming Hard Weekly Contest 141
1093 Statistics from a Large Sample Math,Two Pointers,Probability and Statistics Medium Weekly Contest 142
1094 Car Pooling Array,Prefix Sum,Sorting,Simulation,Heap (Priority Queue) Medium Weekly Contest 142
1095 Find in Mountain Array Array,Binary Search,Interactive Hard Weekly Contest 142
1096 Brace Expansion II Stack,Breadth-First Search,String,Backtracking Hard Weekly Contest 142
1097 Game Play Analysis V Database Hard ๐Ÿ”’
1098 Unpopular Books Database Medium ๐Ÿ”’
1099 Two Sum Less Than K Array,Two Pointers,Binary Search,Sorting Easy ๐Ÿ”’
1100 Find K-Length Substrings With No Repeated Characters Hash Table,String,Sliding Window Medium ๐Ÿ”’
1101 The Earliest Moment When Everyone Become Friends Union Find,Array Medium ๐Ÿ”’
1102 Path With Maximum Minimum Value Depth-First Search,Breadth-First Search,Union Find,Array,Matrix,Heap (Priority Queue) Medium ๐Ÿ”’
1103 Distribute Candies to People Math,Simulation Easy Weekly Contest 143
1104 Path In Zigzag Labelled Binary Tree Tree,Math,Binary Tree Medium Weekly Contest 143
1105 Filling Bookcase Shelves Array,Dynamic Programming Medium Weekly Contest 143
1106 Parsing A Boolean Expression Stack,Recursion,String Hard Weekly Contest 143
1107 New Users Daily Count Database Medium ๐Ÿ”’
1108 Defanging an IP Address String Easy Weekly Contest 144
1109 Corporate Flight Bookings Array,Prefix Sum Medium Weekly Contest 144
1110 Delete Nodes And Return Forest Tree,Depth-First Search,Binary Tree Medium Weekly Contest 144
1111 Maximum Nesting Depth of Two Valid Parentheses Strings Stack,String Medium Weekly Contest 144
1112 Highest Grade For Each Student Database Medium ๐Ÿ”’
1113 Reported Posts Database Easy ๐Ÿ”’
1114 Print in Order Concurrency Easy
1115 Print FooBar Alternately Concurrency Medium
1116 Print Zero Even Odd Concurrency Medium
1117 Building H2O Concurrency Medium
1118 Number of Days in a Month Math Easy ๐Ÿ”’
1119 Remove Vowels from a String String Easy ๐Ÿ”’
1120 Maximum Average Subtree Tree,Depth-First Search,Binary Tree Medium ๐Ÿ”’
1121 Divide Array Into Increasing Sequences Greedy,Array Hard ๐Ÿ”’
1122 Relative Sort Array Array,Hash Table,Counting Sort,Sorting Easy Weekly Contest 145
1123 Lowest Common Ancestor of Deepest Leaves Tree,Depth-First Search,Breadth-First Search,Hash Table,Binary Tree Medium Weekly Contest 145
1124 Longest Well-Performing Interval Stack,Array,Hash Table,Prefix Sum,Monotonic Stack Medium Weekly Contest 145
1125 Smallest Sufficient Team Bit Manipulation,Array,Dynamic Programming,Bitmask Hard Weekly Contest 145
1126 Active Businesses Database Medium ๐Ÿ”’
1127 User Purchase Platform Database Hard ๐Ÿ”’
1128 Number of Equivalent Domino Pairs Array,Hash Table,Counting Easy Weekly Contest 146
1129 Shortest Path with Alternating Colors Breadth-First Search,Graph Medium Weekly Contest 146
1130 Minimum Cost Tree From Leaf Values Stack,Greedy,Dynamic Programming,Monotonic Stack Medium Weekly Contest 146
1131 Maximum of Absolute Value Expression Array,Math Medium Weekly Contest 146
1132 Reported Posts II Database Medium ๐Ÿ”’
1133 Largest Unique Number Array,Hash Table,Sorting Easy ๐Ÿ”’
1134 Armstrong Number Math Easy ๐Ÿ”’
1135 Connecting Cities With Minimum Cost Union Find,Graph,Minimum Spanning Tree,Heap (Priority Queue) Medium ๐Ÿ”’
1136 Parallel Courses Graph,Topological Sort Medium ๐Ÿ”’
1137 N-th Tribonacci Number Memoization,Math,Dynamic Programming Easy Weekly Contest 147
1138 Alphabet Board Path Hash Table,String Medium Weekly Contest 147
1139 Largest 1-Bordered Square Array,Dynamic Programming,Matrix Medium Weekly Contest 147
1140 Stone Game II Array,Math,Dynamic Programming,Game Theory Medium Weekly Contest 147
1141 User Activity for the Past 30 Days I Database Easy
1142 User Activity for the Past 30 Days II Database Easy ๐Ÿ”’
1143 Longest Common Subsequence String,Dynamic Programming Medium
1144 Decrease Elements To Make Array Zigzag Greedy,Array Medium Weekly Contest 148
1145 Binary Tree Coloring Game Tree,Depth-First Search,Binary Tree Medium Weekly Contest 148
1146 Snapshot Array Design,Array,Hash Table,Binary Search Medium Weekly Contest 148
1147 Longest Chunked Palindrome Decomposition Greedy,Two Pointers,String,Dynamic Programming,Hash Function,Rolling Hash Hard Weekly Contest 148
1148 Article Views I Database Easy
1149 Article Views II Database Medium ๐Ÿ”’
1150 Check If a Number Is Majority Element in a Sorted Array Array,Binary Search Easy ๐Ÿ”’
1151 Minimum Swaps to Group All 1's Together Array,Sliding Window Medium ๐Ÿ”’
1152 Analyze User Website Visit Pattern Array,Hash Table,Sorting Medium ๐Ÿ”’
1153 String Transforms Into Another String Hash Table,String Hard ๐Ÿ”’
1154 Day of the Year Math,String Easy Weekly Contest 149
1155 Number of Dice Rolls With Target Sum Dynamic Programming Medium Weekly Contest 149
1156 Swap For Longest Repeated Character Substring String,Sliding Window Medium Weekly Contest 149
1157 Online Majority Element In Subarray Design,Binary Indexed Tree,Segment Tree,Array,Binary Search Hard Weekly Contest 149
1158 Market Analysis I Database Medium
1159 Market Analysis II Database Hard ๐Ÿ”’
1160 Find Words That Can Be Formed by Characters Array,Hash Table,String Easy Weekly Contest 150
1161 Maximum Level Sum of a Binary Tree Tree,Depth-First Search,Breadth-First Search,Binary Tree Medium Weekly Contest 150
1162 As Far from Land as Possible Breadth-First Search,Array,Dynamic Programming,Matrix Medium Weekly Contest 150
1163 Last Substring in Lexicographical Order Two Pointers,String Hard Weekly Contest 150
1164 Product Price at a Given Date Database Medium ๐Ÿ”’
1165 Single-Row Keyboard Hash Table,String Easy ๐Ÿ”’
1166 Design File System Design,Trie,Hash Table,String Medium ๐Ÿ”’
1167 Minimum Cost to Connect Sticks Greedy,Array,Heap (Priority Queue) Medium ๐Ÿ”’
1168 Optimize Water Distribution in a Village Union Find,Graph,Minimum Spanning Tree Hard ๐Ÿ”’
1169 Invalid Transactions Array,Hash Table,String,Sorting Medium Weekly Contest 151
1170 Compare Strings by Frequency of the Smallest Character Array,Hash Table,String,Binary Search,Sorting Medium Weekly Contest 151
1171 Remove Zero Sum Consecutive Nodes from Linked List Hash Table,Linked List Medium Weekly Contest 151
1172 Dinner Plate Stacks Stack,Design,Hash Table,Heap (Priority Queue) Hard Weekly Contest 151
1173 Immediate Food Delivery I Database Easy ๐Ÿ”’
1174 Immediate Food Delivery II Database Medium ๐Ÿ”’
1175 Prime Arrangements Math Easy Weekly Contest 152
1176 Diet Plan Performance Array,Sliding Window Easy ๐Ÿ”’
1177 Can Make Palindrome from Substring Bit Manipulation,Hash Table,String,Prefix Sum Medium Weekly Contest 152
1178 Number of Valid Words for Each Puzzle Bit Manipulation,Trie,Array,Hash Table,String Hard Weekly Contest 152
1179 Reformat Department Table Database Easy
1180 Count Substrings with Only One Distinct Letter Math,String Easy ๐Ÿ”’
1181 Before and After Puzzle Array,Hash Table,String,Sorting Medium ๐Ÿ”’
1182 Shortest Distance to Target Color Array,Binary Search,Dynamic Programming Medium ๐Ÿ”’
1183 Maximum Number of Ones Greedy,Heap (Priority Queue) Hard ๐Ÿ”’
1184 Distance Between Bus Stops Array Easy Weekly Contest 153
1185 Day of the Week Math Easy Weekly Contest 153
1186 Maximum Subarray Sum with One Deletion Array,Dynamic Programming Medium Weekly Contest 153
1187 Make Array Strictly Increasing Array,Binary Search,Dynamic Programming Hard Weekly Contest 153
1188 Design Bounded Blocking Queue Concurrency Medium ๐Ÿ”’
1189 Maximum Number of Balloons Hash Table,String,Counting Easy Weekly Contest 154
1190 Reverse Substrings Between Each Pair of Parentheses Stack,String Medium Weekly Contest 154
1191 K-Concatenation Maximum Sum Array,Dynamic Programming Medium Weekly Contest 154
1192 Critical Connections in a Network Depth-First Search,Graph,Biconnected Component Hard Weekly Contest 154
1193 Monthly Transactions I Database Medium ๐Ÿ”’
1194 Tournament Winners Database Hard ๐Ÿ”’
1195 Fizz Buzz Multithreaded Concurrency Medium
1196 How Many Apples Can You Put into the Basket Greedy,Array,Sorting Easy ๐Ÿ”’
1197 Minimum Knight Moves Breadth-First Search Medium ๐Ÿ”’
1198 Find Smallest Common Element in All Rows Array,Hash Table,Binary Search,Counting,Matrix Medium ๐Ÿ”’
1199 Minimum Time to Build Blocks Greedy,Math,Heap (Priority Queue) Hard ๐Ÿ”’
1200 Minimum Absolute Difference Array,Sorting Easy Weekly Contest 155
1201 Ugly Number III Math,Binary Search,Number Theory Medium Weekly Contest 155
1202 Smallest String With Swaps Depth-First Search,Breadth-First Search,Union Find,Hash Table,String Medium Weekly Contest 155
1203 Sort Items by Groups Respecting Dependencies Depth-First Search,Breadth-First Search,Graph,Topological Sort Hard Weekly Contest 155
1204 Last Person to Fit in the Bus Database Medium ๐Ÿ”’
1205 Monthly Transactions II Database Medium ๐Ÿ”’
1206 Design Skiplist Design,Linked List Hard
1207 Unique Number of Occurrences Array,Hash Table Easy Weekly Contest 156
1208 Get Equal Substrings Within Budget String,Binary Search,Prefix Sum,Sliding Window Medium Weekly Contest 156
1209 Remove All Adjacent Duplicates in String II Stack,String Medium Weekly Contest 156
1210 Minimum Moves to Reach Target with Rotations Breadth-First Search,Array,Matrix Hard Weekly Contest 156
1211 Queries Quality and Percentage Database Easy ๐Ÿ”’
1212 Team Scores in Football Tournament Database Medium ๐Ÿ”’
1213 Intersection of Three Sorted Arrays Array,Hash Table,Binary Search,Counting Easy ๐Ÿ”’
1214 Two Sum BSTs Stack,Tree,Depth-First Search,Binary Search Tree,Two Pointers,Binary Search,Binary Tree Medium ๐Ÿ”’
1215 Stepping Numbers Breadth-First Search,Backtracking Medium ๐Ÿ”’
1216 Valid Palindrome III String,Dynamic Programming Hard ๐Ÿ”’
1217 Minimum Cost to Move Chips to The Same Position Greedy,Array,Math Easy Weekly Contest 157
1218 Longest Arithmetic Subsequence of Given Difference Array,Hash Table,Dynamic Programming Medium Weekly Contest 157
1219 Path with Maximum Gold Array,Backtracking,Matrix Medium Weekly Contest 157
1220 Count Vowels Permutation Dynamic Programming Hard Weekly Contest 157
1221 Split a String in Balanced Strings Greedy,String,Counting Easy Weekly Contest 158
1222 Queens That Can Attack the King Array,Matrix,Simulation Medium Weekly Contest 158
1223 Dice Roll Simulation Array,Dynamic Programming Hard Weekly Contest 158
1224 Maximum Equal Frequency Array,Hash Table Hard Weekly Contest 158
1225 Report Contiguous Dates Database Hard ๐Ÿ”’
1226 The Dining Philosophers Concurrency Medium
1227 Airplane Seat Assignment Probability Brainteaser,Math,Dynamic Programming,Probability and Statistics Medium
1228 Missing Number In Arithmetic Progression Array,Math Easy ๐Ÿ”’
1229 Meeting Scheduler Array,Two Pointers,Sorting Medium ๐Ÿ”’
1230 Toss Strange Coins Math,Dynamic Programming,Probability and Statistics Medium ๐Ÿ”’
1231 Divide Chocolate Array,Binary Search Hard ๐Ÿ”’
1232 Check If It Is a Straight Line Geometry,Array,Math Easy Weekly Contest 159
1233 Remove Sub-Folders from the Filesystem Trie,Array,String Medium Weekly Contest 159
1234 Replace the Substring for Balanced String String,Sliding Window Medium Weekly Contest 159
1235 Maximum Profit in Job Scheduling Array,Binary Search,Dynamic Programming,Sorting Hard Weekly Contest 159
1236 Web Crawler Depth-First Search,Breadth-First Search,String,Interactive Medium ๐Ÿ”’
1237 Find Positive Integer Solution for a Given Equation Math,Two Pointers,Binary Search,Interactive Medium Weekly Contest 160
1238 Circular Permutation in Binary Representation Bit Manipulation,Math,Backtracking Medium Weekly Contest 160
1239 Maximum Length of a Concatenated String with Unique Characters Bit Manipulation,Array,String,Backtracking Medium Weekly Contest 160
1240 Tiling a Rectangle with the Fewest Squares Dynamic Programming,Backtracking Hard Weekly Contest 160
1241 Number of Comments per Post Database Easy ๐Ÿ”’
1242 Web Crawler Multithreaded Depth-First Search,Breadth-First Search,Concurrency Medium ๐Ÿ”’
1243 Array Transformation Array,Simulation Easy ๐Ÿ”’
1244 Design A Leaderboard Design,Hash Table,Sorting Medium ๐Ÿ”’
1245 Tree Diameter Tree,Depth-First Search,Breadth-First Search,Graph,Topological Sort Medium ๐Ÿ”’
1246 Palindrome Removal Array,Dynamic Programming Hard ๐Ÿ”’
1247 Minimum Swaps to Make Strings Equal Greedy,Math,String Medium Weekly Contest 161
1248 Count Number of Nice Subarrays Array,Hash Table,Math,Sliding Window Medium Weekly Contest 161
1249 Minimum Remove to Make Valid Parentheses Stack,String Medium Weekly Contest 161
1250 Check If It Is a Good Array Array,Math,Number Theory Hard Weekly Contest 161
1251 Average Selling Price Database Easy ๐Ÿ”’
1252 Cells with Odd Values in a Matrix Array,Math,Simulation Easy Weekly Contest 162
1253 Reconstruct a 2-Row Binary Matrix Greedy,Array,Matrix Medium Weekly Contest 162
1254 Number of Closed Islands Depth-First Search,Breadth-First Search,Union Find,Array,Matrix Medium Weekly Contest 162
1255 Maximum Score Words Formed by Letters Bit Manipulation,Array,String,Dynamic Programming,Backtracking,Bitmask Hard Weekly Contest 162
1256 Encode Number Bit Manipulation,Math,String Medium ๐Ÿ”’
1257 Smallest Common Region Tree,Depth-First Search,Breadth-First Search,Array,Hash Table,String Medium ๐Ÿ”’
1258 Synonymous Sentences Union Find,Array,Hash Table,String,Backtracking Medium ๐Ÿ”’
1259 Handshakes That Don't Cross Math,Dynamic Programming Hard ๐Ÿ”’
1260 Shift 2D Grid Array,Matrix,Simulation Easy Weekly Contest 163
1261 Find Elements in a Contaminated Binary Tree Tree,Depth-First Search,Breadth-First Search,Design,Hash Table,Binary Tree Medium Weekly Contest 163
1262 Greatest Sum Divisible by Three Greedy,Array,Dynamic Programming Medium Weekly Contest 163
1263 Minimum Moves to Move a Box to Their Target Location Breadth-First Search,Array,Matrix,Heap (Priority Queue) Hard Weekly Contest 163
1264 Page Recommendations Database Medium ๐Ÿ”’
1265 Print Immutable Linked List in Reverse Stack,Recursion,Linked List,Two Pointers Medium ๐Ÿ”’
1266 Minimum Time Visiting All Points Geometry,Array,Math Easy Weekly Contest 164
1267 Count Servers that Communicate Depth-First Search,Breadth-First Search,Union Find,Array,Counting,Matrix Medium Weekly Contest 164
1268 Search Suggestions System Trie,Array,String Medium Weekly Contest 164
1269 Number of Ways to Stay in the Same Place After Some Steps Dynamic Programming Hard Weekly Contest 164
1270 All People Report to the Given Manager Database Medium ๐Ÿ”’
1271 Hexspeak Math,String Easy ๐Ÿ”’
1272 Remove Interval Array Medium ๐Ÿ”’
1273 Delete Tree Nodes Tree,Depth-First Search,Breadth-First Search Medium ๐Ÿ”’
1274 Number of Ships in a Rectangle Array,Divide and Conquer,Interactive Hard ๐Ÿ”’
1275 Find Winner on a Tic Tac Toe Game Array,Hash Table,Matrix,Simulation Easy Weekly Contest 165
1276 Number of Burgers with No Waste of Ingredients Math Medium Weekly Contest 165
1277 Count Square Submatrices with All Ones Array,Dynamic Programming,Matrix Medium Weekly Contest 165
1278 Palindrome Partitioning III String,Dynamic Programming Hard Weekly Contest 165
1279 Traffic Light Controlled Intersection Concurrency Easy ๐Ÿ”’
1280 Students and Examinations Database Easy ๐Ÿ”’
1281 Subtract the Product and Sum of Digits of an Integer Math Easy Weekly Contest 166
1282 Group the People Given the Group Size They Belong To Array,Hash Table Medium Weekly Contest 166
1283 Find the Smallest Divisor Given a Threshold Array,Binary Search Medium Weekly Contest 166
1284 Minimum Number of Flips to Convert Binary Matrix to Zero Matrix Bit Manipulation,Breadth-First Search,Array,Matrix Hard Weekly Contest 166
1285 Find the Start and End Number of Continuous Ranges Database Medium ๐Ÿ”’
1286 Iterator for Combination Design,String,Backtracking,Iterator Medium Biweekly Contest 15
1287 Element Appearing More Than 25% In Sorted Array Array Easy Biweekly Contest 15
1288 Remove Covered Intervals Array,Sorting Medium Biweekly Contest 15
1289 Minimum Falling Path Sum II Array,Dynamic Programming,Matrix Hard Biweekly Contest 15
1290 Convert Binary Number in a Linked List to Integer Linked List,Math Easy Weekly Contest 167
1291 Sequential Digits Enumeration Medium Weekly Contest 167
1292 Maximum Side Length of a Square with Sum Less than or Equal to Threshold Array,Binary Search,Matrix,Prefix Sum Medium Weekly Contest 167
1293 Shortest Path in a Grid with Obstacles Elimination Breadth-First Search,Array,Matrix Hard Weekly Contest 167
1294 Weather Type in Each Country Database Easy ๐Ÿ”’
1295 Find Numbers with Even Number of Digits Array Easy Weekly Contest 168
1296 Divide Array in Sets of K Consecutive Numbers Greedy,Array,Hash Table,Sorting Medium Weekly Contest 168
1297 Maximum Number of Occurrences of a Substring Hash Table,String,Sliding Window Medium Weekly Contest 168
1298 Maximum Candies You Can Get from Boxes Breadth-First Search,Array Hard Weekly Contest 168
1299 Replace Elements with Greatest Element on Right Side Array Easy Biweekly Contest 16
1300 Sum of Mutated Array Closest to Target Array,Binary Search,Sorting Medium Biweekly Contest 16
1301 Number of Paths with Max Score Array,Dynamic Programming,Matrix Hard Biweekly Contest 16
1302 Deepest Leaves Sum Tree,Depth-First Search,Breadth-First Search,Binary Tree Medium Biweekly Contest 16
1303 Find the Team Size Database Easy ๐Ÿ”’
1304 Find N Unique Integers Sum up to Zero Array,Math Easy Weekly Contest 169
1305 All Elements in Two Binary Search Trees Tree,Depth-First Search,Binary Search Tree,Binary Tree,Sorting Medium Weekly Contest 169
1306 Jump Game III Depth-First Search,Breadth-First Search,Array Medium Weekly Contest 169
1307 Verbal Arithmetic Puzzle Array,Math,String,Backtracking Hard Weekly Contest 169
1308 Running Total for Different Genders Database Medium ๐Ÿ”’
1309 Decrypt String from Alphabet to Integer Mapping String Easy Weekly Contest 170
1310 XOR Queries of a Subarray Bit Manipulation,Array,Prefix Sum Medium Weekly Contest 170
1311 Get Watched Videos by Your Friends Breadth-First Search,Array,Hash Table,Sorting Medium Weekly Contest 170
1312 Minimum Insertion Steps to Make a String Palindrome String,Dynamic Programming Hard Weekly Contest 170
1313 Decompress Run-Length Encoded List Array Easy Biweekly Contest 17
1314 Matrix Block Sum Array,Matrix,Prefix Sum Medium Biweekly Contest 17
1315 Sum of Nodes with Even-Valued Grandparent Tree,Depth-First Search,Breadth-First Search,Binary Tree Medium Biweekly Contest 17
1316 Distinct Echo Substrings Trie,String,Dynamic Programming,Sliding Window,Hash Function,Rolling Hash Hard Biweekly Contest 17
1317 Convert Integer to the Sum of Two No-Zero Integers Math Easy Weekly Contest 171
1318 Minimum Flips to Make a OR b Equal to c Bit Manipulation Medium Weekly Contest 171
1319 Number of Operations to Make Network Connected Depth-First Search,Breadth-First Search,Union Find,Graph Medium Weekly Contest 171
1320 Minimum Distance to Type a Word Using Two Fingers String,Dynamic Programming Hard Weekly Contest 171
1321 Restaurant Growth Database Medium ๐Ÿ”’
1322 Ads Performance Database Easy ๐Ÿ”’
1323 Maximum 69 Number Greedy,Math Easy Weekly Contest 172
1324 Print Words Vertically Array,String,Simulation Medium Weekly Contest 172
1325 Delete Leaves With a Given Value Tree,Depth-First Search,Binary Tree Medium Weekly Contest 172
1326 Minimum Number of Taps to Open to Water a Garden Greedy,Array,Dynamic Programming Hard Weekly Contest 172
1327 List the Products Ordered in a Period Database Easy ๐Ÿ”’
1328 Break a Palindrome Greedy,String Medium Biweekly Contest 18
1329 Sort the Matrix Diagonally Array,Matrix,Sorting Medium Biweekly Contest 18
1330 Reverse Subarray To Maximize Array Value Greedy,Array,Math Hard Biweekly Contest 18
1331 Rank Transform of an Array Array,Hash Table,Sorting Easy Biweekly Contest 18
1332 Remove Palindromic Subsequences Two Pointers,String Easy Weekly Contest 173
1333 Filter Restaurants by Vegan-Friendly, Price and Distance Array,Sorting Medium Weekly Contest 173
1334 Find the City With the Smallest Number of Neighbors at a Threshold Distance Graph,Dynamic Programming,Shortest Path Medium Weekly Contest 173
1335 Minimum Difficulty of a Job Schedule Array,Dynamic Programming Hard Weekly Contest 173
1336 Number of Transactions per Visit Database Hard ๐Ÿ”’
1337 The K Weakest Rows in a Matrix Array,Binary Search,Matrix,Sorting,Heap (Priority Queue) Easy Weekly Contest 174
1338 Reduce Array Size to The Half Greedy,Array,Hash Table,Sorting,Heap (Priority Queue) Medium Weekly Contest 174
1339 Maximum Product of Splitted Binary Tree Tree,Depth-First Search,Binary Tree Medium Weekly Contest 174
1340 Jump Game V Array,Dynamic Programming,Sorting Hard Weekly Contest 174
1341 Movie Rating Database Medium ๐Ÿ”’
1342 Number of Steps to Reduce a Number to Zero Bit Manipulation,Math Easy Biweekly Contest 19
1343 Number of Sub-arrays of Size K and Average Greater than or Equal to Threshold Array,Sliding Window Medium Biweekly Contest 19
1344 Angle Between Hands of a Clock Math Medium Biweekly Contest 19
1345 Jump Game IV Breadth-First Search,Array,Hash Table Hard Biweekly Contest 19
1346 Check If N and Its Double Exist Array,Hash Table,Two Pointers,Binary Search,Sorting Easy Weekly Contest 175
1347 Minimum Number of Steps to Make Two Strings Anagram Hash Table,String,Counting Medium Weekly Contest 175
1348 Tweet Counts Per Frequency Design,Hash Table,Binary Search,Ordered Set,Sorting Medium Weekly Contest 175
1349 Maximum Students Taking Exam Bit Manipulation,Array,Dynamic Programming,Bitmask,Matrix Hard Weekly Contest 175
1350 Students With Invalid Departments Database Easy ๐Ÿ”’
1351 Count Negative Numbers in a Sorted Matrix Array,Binary Search,Matrix Easy Weekly Contest 176
1352 Product of the Last K Numbers Design,Queue,Array,Math,Data Stream Medium Weekly Contest 176
1353 Maximum Number of Events That Can Be Attended Greedy,Array,Heap (Priority Queue) Medium Weekly Contest 176
1354 Construct Target Array With Multiple Sums Array,Heap (Priority Queue) Hard Weekly Contest 176
1355 Activity Participants Database Medium ๐Ÿ”’
1356 Sort Integers by The Number of 1 Bits Bit Manipulation,Array,Counting,Sorting Easy Biweekly Contest 20
1357 Apply Discount Every n Orders Design,Array,Hash Table Medium Biweekly Contest 20
1358 Number of Substrings Containing All Three Characters Hash Table,String,Sliding Window Medium Biweekly Contest 20
1359 Count All Valid Pickup and Delivery Options Math,Dynamic Programming,Combinatorics Hard Biweekly Contest 20
1360 Number of Days Between Two Dates Math,String Easy Weekly Contest 177
1361 Validate Binary Tree Nodes Tree,Depth-First Search,Breadth-First Search,Union Find,Graph,Binary Tree Medium Weekly Contest 177
1362 Closest Divisors Math Medium Weekly Contest 177
1363 Largest Multiple of Three Greedy,Array,Dynamic Programming Hard Weekly Contest 177
1364 Number of Trusted Contacts of a Customer Database Medium ๐Ÿ”’
1365 How Many Numbers Are Smaller Than the Current Number Array,Hash Table,Counting,Sorting Easy Weekly Contest 178
1366 Rank Teams by Votes Array,Hash Table,String,Counting,Sorting Medium Weekly Contest 178
1367 Linked List in Binary Tree Tree,Depth-First Search,Breadth-First Search,Linked List,Binary Tree Medium Weekly Contest 178
1368 Minimum Cost to Make at Least One Valid Path in a Grid Breadth-First Search,Graph,Array,Matrix,Shortest Path,Heap (Priority Queue) Hard Weekly Contest 178
1369 Get the Second Most Recent Activity Database Hard ๐Ÿ”’
1370 Increasing Decreasing String Hash Table,String,Counting Easy Biweekly Contest 21
1371 Find the Longest Substring Containing Vowels in Even Counts Bit Manipulation,Hash Table,String,Prefix Sum Medium Biweekly Contest 21
1372 Longest ZigZag Path in a Binary Tree Tree,Depth-First Search,Dynamic Programming,Binary Tree Medium Biweekly Contest 21
1373 Maximum Sum BST in Binary Tree Tree,Depth-First Search,Binary Search Tree,Dynamic Programming,Binary Tree Hard Biweekly Contest 21
1374 Generate a String With Characters That Have Odd Counts String Easy Weekly Contest 179
1375 Number of Times Binary String Is Prefix-Aligned Array Medium Weekly Contest 179
1376 Time Needed to Inform All Employees Tree,Depth-First Search,Breadth-First Search Medium Weekly Contest 179
1377 Frog Position After T Seconds Tree,Depth-First Search,Breadth-First Search,Graph Hard Weekly Contest 179
1378 Replace Employee ID With The Unique Identifier Database Easy ๐Ÿ”’
1379 Find a Corresponding Node of a Binary Tree in a Clone of That Tree Tree,Depth-First Search,Breadth-First Search,Binary Tree Medium
1380 Lucky Numbers in a Matrix Array,Matrix Easy Weekly Contest 180
1381 Design a Stack With Increment Operation Stack,Design,Array Medium Weekly Contest 180
1382 Balance a Binary Search Tree Greedy,Tree,Depth-First Search,Binary Search Tree,Divide and Conquer,Binary Tree Medium Weekly Contest 180
1383 Maximum Performance of a Team Greedy,Array,Sorting,Heap (Priority Queue) Hard Weekly Contest 180
1384 Total Sales Amount by Year Database Hard ๐Ÿ”’
1385 Find the Distance Value Between Two Arrays Array,Two Pointers,Binary Search,Sorting Easy Biweekly Contest 22
1386 Cinema Seat Allocation Greedy,Bit Manipulation,Array,Hash Table Medium Biweekly Contest 22
1387 Sort Integers by The Power Value Memoization,Dynamic Programming,Sorting Medium Biweekly Contest 22
1388 Pizza With 3n Slices Greedy,Array,Dynamic Programming,Heap (Priority Queue) Hard Biweekly Contest 22
1389 Create Target Array in the Given Order Array,Simulation Easy Weekly Contest 181
1390 Four Divisors Array,Math Medium Weekly Contest 181
1391 Check if There is a Valid Path in a Grid Depth-First Search,Breadth-First Search,Union Find,Array,Matrix Medium Weekly Contest 181
1392 Longest Happy Prefix String,String Matching,Hash Function,Rolling Hash Hard Weekly Contest 181
1393 Capital GainLoss Database Medium
1394 Find Lucky Integer in an Array Array,Hash Table,Counting Easy Weekly Contest 182
1395 Count Number of Teams Binary Indexed Tree,Array,Dynamic Programming Medium Weekly Contest 182
1396 Design Underground System Design,Hash Table,String Medium Weekly Contest 182
1397 Find All Good Strings String,Dynamic Programming,String Matching Hard Weekly Contest 182
1398 Customers Who Bought Products A and B but Not C Database Medium ๐Ÿ”’
1399 Count Largest Group Hash Table,Math Easy Biweekly Contest 23
1400 Construct K Palindrome Strings Greedy,Hash Table,String,Counting Medium Biweekly Contest 23
1401 Circle and Rectangle Overlapping Geometry,Math Medium Biweekly Contest 23
1402 Reducing Dishes Greedy,Array,Dynamic Programming,Sorting Hard Biweekly Contest 23
1403 Minimum Subsequence in Non-Increasing Order Greedy,Array,Sorting Easy Weekly Contest 183
1404 Number of Steps to Reduce a Number in Binary Representation to One Bit Manipulation,String Medium Weekly Contest 183
1405 Longest Happy String Greedy,String,Heap (Priority Queue) Medium Weekly Contest 183
1406 Stone Game III Array,Math,Dynamic Programming,Game Theory Hard Weekly Contest 183
1407 Top Travellers Database Easy
1408 String Matching in an Array String,String Matching Easy Weekly Contest 184
1409 Queries on a Permutation With Key Binary Indexed Tree,Array,Simulation Medium Weekly Contest 184
1410 HTML Entity Parser Hash Table,String Medium Weekly Contest 184
1411 Number of Ways to Paint N ร— 3 Grid Dynamic Programming Hard Weekly Contest 184
1412 Find the Quiet Students in All Exams Database Hard ๐Ÿ”’
1413 Minimum Value to Get Positive Step by Step Sum Array,Prefix Sum Easy Biweekly Contest 24
1414 Find the Minimum Number of Fibonacci Numbers Whose Sum Is K Greedy Medium Biweekly Contest 24
1415 The k-th Lexicographical String of All Happy Strings of Length n String,Backtracking Medium Biweekly Contest 24
1416 Restore The Array String,Dynamic Programming Hard Biweekly Contest 24
1417 Reformat The String String Easy Weekly Contest 185
1418 Display Table of Food Orders in a Restaurant Array,Hash Table,String,Ordered Set,Sorting Medium Weekly Contest 185
1419 Minimum Number of Frogs Croaking String,Counting Medium Weekly Contest 185
1420 Build Array Where You Can Find The Maximum Exactly K Comparisons Dynamic Programming Hard Weekly Contest 185
1421 NPV Queries Database Easy ๐Ÿ”’
1422 Maximum Score After Splitting a String String Easy Weekly Contest 186
1423 Maximum Points You Can Obtain from Cards Array,Prefix Sum,Sliding Window Medium Weekly Contest 186
1424 Diagonal Traverse II Array,Sorting,Heap (Priority Queue) Medium Weekly Contest 186
1425 Constrained Subsequence Sum Queue,Array,Dynamic Programming,Sliding Window,Monotonic Queue,Heap (Priority Queue) Hard Weekly Contest 186
1426 Counting Elements Array,Hash Table Easy ๐Ÿ”’
1427 Perform String Shifts Array,Math,String Easy ๐Ÿ”’
1428 Leftmost Column with at Least a One Array,Binary Search,Interactive,Matrix Medium ๐Ÿ”’
1429 First Unique Number Design,Queue,Array,Hash Table,Data Stream Medium ๐Ÿ”’
1430 Check If a String Is a Valid Sequence from Root to Leaves Path in a Binary Tree Tree,Depth-First Search,Breadth-First Search,Binary Tree Medium ๐Ÿ”’
1431 Kids With the Greatest Number of Candies Array Easy Biweekly Contest 25
1432 Max Difference You Can Get From Changing an Integer Greedy,Math Medium Biweekly Contest 25
1433 Check If a String Can Break Another String Greedy,String,Sorting Medium Biweekly Contest 25
1434 Number of Ways to Wear Different Hats to Each Other Bit Manipulation,Array,Dynamic Programming,Bitmask Hard Biweekly Contest 25
1435 Create a Session Bar Chart Database Easy ๐Ÿ”’
1436 Destination City Hash Table,String Easy Weekly Contest 187
1437 Check If All 1's Are at Least Length K Places Away Array Easy Weekly Contest 187
1438 Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit Queue,Array,Ordered Set,Sliding Window,Monotonic Queue,Heap (Priority Queue) Medium Weekly Contest 187
1439 Find the Kth Smallest Sum of a Matrix With Sorted Rows Array,Binary Search,Matrix,Heap (Priority Queue) Hard Weekly Contest 187
1440 Evaluate Boolean Expression Database Medium ๐Ÿ”’
1441 Build an Array With Stack Operations Stack,Array,Simulation Easy Weekly Contest 188
1442 Count Triplets That Can Form Two Arrays of Equal XOR Bit Manipulation,Array,Hash Table,Math,Prefix Sum Medium Weekly Contest 188
1443 Minimum Time to Collect All Apples in a Tree Tree,Depth-First Search,Breadth-First Search,Hash Table Medium Weekly Contest 188
1444 Number of Ways of Cutting a Pizza Memoization,Array,Dynamic Programming,Matrix Hard Weekly Contest 188
1445 Apples & Oranges Database Medium ๐Ÿ”’
1446 Consecutive Characters String Easy Biweekly Contest 26
1447 Simplified Fractions Math,String,Number Theory Medium Biweekly Contest 26
1448 Count Good Nodes in Binary Tree Tree,Depth-First Search,Breadth-First Search,Binary Tree Medium Biweekly Contest 26
1449 Form Largest Integer With Digits That Add up to Target Array,Dynamic Programming Hard Biweekly Contest 26
1450 Number of Students Doing Homework at a Given Time Array Easy Weekly Contest 189
1451 Rearrange Words in a Sentence String,Sorting Medium Weekly Contest 189
1452 People Whose List of Favorite Companies Is Not a Subset of Another List Array,Hash Table,String Medium Weekly Contest 189
1453 Maximum Number of Darts Inside of a Circular Dartboard Geometry,Array,Math Hard Weekly Contest 189
1454 Active Users Database Medium ๐Ÿ”’
1455 Check If a Word Occurs As a Prefix of Any Word in a Sentence String,String Matching Easy Weekly Contest 190
1456 Maximum Number of Vowels in a Substring of Given Length String,Sliding Window Medium Weekly Contest 190
1457 Pseudo-Palindromic Paths in a Binary Tree Bit Manipulation,Tree,Depth-First Search,Breadth-First Search,Binary Tree Medium Weekly Contest 190
1458 Max Dot Product of Two Subsequences Array,Dynamic Programming Hard Weekly Contest 190
1459 Rectangles Area Database Medium ๐Ÿ”’
1460 Make Two Arrays Equal by Reversing Sub-arrays Array,Hash Table,Sorting Easy Biweekly Contest 27
1461 Check If a String Contains All Binary Codes of Size K Bit Manipulation,Hash Table,String,Hash Function,Rolling Hash Medium Biweekly Contest 27
1462 Course Schedule IV Depth-First Search,Breadth-First Search,Graph,Topological Sort Medium Biweekly Contest 27
1463 Cherry Pickup II Array,Dynamic Programming,Matrix Hard Biweekly Contest 27
1464 Maximum Product of Two Elements in an Array Array,Sorting,Heap (Priority Queue) Easy Weekly Contest 191
1465 Maximum Area of a Piece of Cake After Horizontal and Vertical Cuts Greedy,Array,Sorting Medium Weekly Contest 191
1466 Reorder Routes to Make All Paths Lead to the City Zero Depth-First Search,Breadth-First Search,Graph Medium Weekly Contest 191
1467 Probability of a Two Boxes Having The Same Number of Distinct Balls Math,Dynamic Programming,Backtracking,Combinatorics,Probability and Statistics Hard Weekly Contest 191
1468 Calculate Salaries Database Medium ๐Ÿ”’
1469 Find All The Lonely Nodes Tree,Depth-First Search,Breadth-First Search,Binary Tree Easy ๐Ÿ”’
1470 Shuffle the Array Array Easy Weekly Contest 192
1471 The k Strongest Values in an Array Array,Two Pointers,Sorting Medium Weekly Contest 192
1472 Design Browser History Stack,Design,Array,Linked List,Data Stream,Doubly-Linked List Medium Weekly Contest 192
1473 Paint House III Array,Dynamic Programming Hard Weekly Contest 192
1474 Delete N Nodes After M Nodes of a Linked List Linked List Easy ๐Ÿ”’
1475 Final Prices With a Special Discount in a Shop Stack,Array,Monotonic Stack Easy Biweekly Contest 28
1476 Subrectangle Queries Design,Array,Matrix Medium Biweekly Contest 28
1477 Find Two Non-overlapping Sub-arrays Each With Target Sum Array,Hash Table,Binary Search,Dynamic Programming,Sliding Window Medium Biweekly Contest 28
1478 Allocate Mailboxes Array,Math,Dynamic Programming,Sorting Hard Biweekly Contest 28
1479 Sales by Day of the Week Database Hard ๐Ÿ”’
1480 Running Sum of 1d Array Array,Prefix Sum Easy Weekly Contest 193
1481 Least Number of Unique Integers after K Removals Greedy,Array,Hash Table,Counting,Sorting Medium Weekly Contest 193
1482 Minimum Number of Days to Make m Bouquets Array,Binary Search Medium Weekly Contest 193
1483 Kth Ancestor of a Tree Node Tree,Depth-First Search,Breadth-First Search,Design,Binary Search,Dynamic Programming Hard Weekly Contest 193
1484 Group Sold Products By The Date Database Easy
1485 Clone Binary Tree With Random Pointer Tree,Depth-First Search,Breadth-First Search,Hash Table,Binary Tree Medium ๐Ÿ”’
1486 XOR Operation in an Array Bit Manipulation,Math Easy Weekly Contest 194
1487 Making File Names Unique Array,Hash Table,String Medium Weekly Contest 194
1488 Avoid Flood in The City Greedy,Array,Hash Table,Binary Search,Heap (Priority Queue) Medium Weekly Contest 194
1489 Find Critical and Pseudo-Critical Edges in Minimum Spanning Tree Union Find,Graph,Minimum Spanning Tree,Sorting,Strongly Connected Component Hard Weekly Contest 194
1490 Clone N-ary Tree Tree,Depth-First Search,Breadth-First Search,Hash Table Medium ๐Ÿ”’
1491 Average Salary Excluding the Minimum and Maximum Salary Array,Sorting Easy Biweekly Contest 29
1492 The kth Factor of n Math Medium Biweekly Contest 29
1493 Longest Subarray of 1's After Deleting One Element Math,Dynamic Programming,Sliding Window Medium Biweekly Contest 29
1494 Parallel Courses II Bit Manipulation,Graph,Dynamic Programming,Bitmask Hard Biweekly Contest 29
1495 Friendly Movies Streamed Last Month Database Easy ๐Ÿ”’
1496 Path Crossing Hash Table,String Easy Weekly Contest 195
1497 Check If Array Pairs Are Divisible by k Array,Hash Table,Counting Medium Weekly Contest 195
1498 Number of Subsequences That Satisfy the Given Sum Condition Array,Two Pointers,Binary Search,Sorting Medium Weekly Contest 195
1499 Max Value of Equation Queue,Array,Sliding Window,Monotonic Queue,Heap (Priority Queue) Hard Weekly Contest 195
1500 Design a File Sharing System Design,Hash Table,Data Stream,Heap (Priority Queue) Medium ๐Ÿ”’
1501 Countries You Can Safely Invest In Database Medium ๐Ÿ”’
1502 Can Make Arithmetic Progression From Sequence Array,Sorting Easy Weekly Contest 196
1503 Last Moment Before All Ants Fall Out of a Plank Brainteaser,Array,Simulation Medium Weekly Contest 196
1504 Count Submatrices With All Ones Stack,Array,Dynamic Programming,Matrix,Monotonic Stack Medium Weekly Contest 196
1505 Minimum Possible Integer After at Most K Adjacent Swaps On Digits Greedy,Binary Indexed Tree,Segment Tree,String Hard Weekly Contest 196
1506 Find Root of N-Ary Tree Bit Manipulation,Tree,Depth-First Search,Hash Table Medium ๐Ÿ”’
1507 Reformat Date String Easy Biweekly Contest 30
1508 Range Sum of Sorted Subarray Sums Array,Two Pointers,Binary Search,Sorting Medium Biweekly Contest 30
1509 Minimum Difference Between Largest and Smallest Value in Three Moves Greedy,Array,Sorting Medium Biweekly Contest 30
1510 Stone Game IV Math,Dynamic Programming,Game Theory Hard Biweekly Contest 30
1511 Customer Order Frequency Database Easy ๐Ÿ”’
1512 Number of Good Pairs Array,Hash Table,Math,Counting Easy Weekly Contest 197
1513 Number of Substrings With Only 1s Math,String Medium Weekly Contest 197
1514 Path with Maximum Probability Graph,Shortest Path,Heap (Priority Queue) Medium Weekly Contest 197
1515 Best Position for a Service Centre Geometry,Math,Randomized Hard Weekly Contest 197
1516 Move Sub-Tree of N-Ary Tree Tree,Depth-First Search Hard ๐Ÿ”’
1517 Find Users With Valid E-Mails Database Easy ๐Ÿ”’
1518 Water Bottles Math,Simulation Easy Weekly Contest 198
1519 Number of Nodes in the Sub-Tree With the Same Label Tree,Depth-First Search,Breadth-First Search,Hash Table,Counting Medium Weekly Contest 198
1520 Maximum Number of Non-Overlapping Substrings Greedy,String Hard Weekly Contest 198
1521 Find a Value of a Mysterious Function Closest to Target Bit Manipulation,Segment Tree,Array,Binary Search Hard Weekly Contest 198
1522 Diameter of N-Ary Tree Tree,Depth-First Search Medium ๐Ÿ”’
1523 Count Odd Numbers in an Interval Range Math Easy Biweekly Contest 31
1524 Number of Sub-arrays With Odd Sum Array,Math,Dynamic Programming,Prefix Sum Medium Biweekly Contest 31
1525 Number of Good Ways to Split a String Bit Manipulation,String,Dynamic Programming Medium Biweekly Contest 31
1526 Minimum Number of Increments on Subarrays to Form a Target Array Stack,Greedy,Array,Dynamic Programming,Monotonic Stack Hard Biweekly Contest 31
1527 Patients With a Condition Database Easy
1528 Shuffle String Array,String Easy Weekly Contest 199
1529 Minimum Suffix Flips Greedy,String Medium Weekly Contest 199
1530 Number of Good Leaf Nodes Pairs Tree,Depth-First Search,Binary Tree Medium Weekly Contest 199
1531 String Compression II String,Dynamic Programming Hard Weekly Contest 199
1532 The Most Recent Three Orders Database Medium ๐Ÿ”’
1533 Find the Index of the Large Integer Array,Binary Search,Interactive Medium ๐Ÿ”’
1534 Count Good Triplets Array,Enumeration Easy Weekly Contest 200
1535 Find the Winner of an Array Game Array,Simulation Medium Weekly Contest 200
1536 Minimum Swaps to Arrange a Binary Grid Greedy,Array,Matrix Medium Weekly Contest 200
1537 Get the Maximum Score Greedy,Array,Two Pointers,Dynamic Programming Hard Weekly Contest 200
1538 Guess the Majority in a Hidden Array Array,Math,Interactive Medium ๐Ÿ”’
1539 Kth Missing Positive Number Array,Binary Search Easy Biweekly Contest 32
1540 Can Convert String in K Moves Hash Table,String Medium Biweekly Contest 32
1541 Minimum Insertions to Balance a Parentheses String Stack,Greedy,String Medium Biweekly Contest 32
1542 Find Longest Awesome Substring Bit Manipulation,Hash Table,String Hard Biweekly Contest 32
1543 Fix Product Name Format Database Easy ๐Ÿ”’
1544 Make The String Great Stack,String Easy Weekly Contest 201
1545 Find Kth Bit in Nth Binary String Recursion,String Medium Weekly Contest 201
1546 Maximum Number of Non-Overlapping Subarrays With Sum Equals Target Greedy,Array,Hash Table,Prefix Sum Medium Weekly Contest 201
1547 Minimum Cost to Cut a Stick Array,Dynamic Programming Hard Weekly Contest 201
1548 The Most Similar Path in a Graph Graph,Dynamic Programming Hard ๐Ÿ”’
1549 The Most Recent Orders for Each Product Database Medium ๐Ÿ”’
1550 Three Consecutive Odds Array Easy Weekly Contest 202
1551 Minimum Operations to Make Array Equal Math Medium Weekly Contest 202
1552 Magnetic Force Between Two Balls Array,Binary Search,Sorting Medium Weekly Contest 202
1553 Minimum Number of Days to Eat N Oranges Memoization,Dynamic Programming Hard Weekly Contest 202
1554 Strings Differ by One Character Hash Table,String,Hash Function,Rolling Hash Medium ๐Ÿ”’
1555 Bank Account Summary Database Medium ๐Ÿ”’
1556 Thousand Separator String Easy Biweekly Contest 33
1557 Minimum Number of Vertices to Reach All Nodes Graph Medium Biweekly Contest 33
1558 Minimum Numbers of Function Calls to Make Target Array Greedy,Array Medium Biweekly Contest 33
1559 Detect Cycles in 2D Grid Depth-First Search,Breadth-First Search,Union Find,Array,Matrix Medium Biweekly Contest 33
1560 Most Visited Sector in a Circular Track Array,Simulation Easy Weekly Contest 203
1561 Maximum Number of Coins You Can Get Greedy,Array,Math,Game Theory,Sorting Medium Weekly Contest 203
1562 Find Latest Group of Size M Array,Binary Search,Simulation Medium Weekly Contest 203
1563 Stone Game V Array,Math,Dynamic Programming,Game Theory Hard Weekly Contest 203
1564 Put Boxes Into the Warehouse I Greedy,Array,Sorting Medium ๐Ÿ”’
1565 Unique Orders and Customers Per Month Database Easy ๐Ÿ”’
1566 Detect Pattern of Length M Repeated K or More Times Array,Enumeration Easy Weekly Contest 204
1567 Maximum Length of Subarray With Positive Product Greedy,Array,Dynamic Programming Medium Weekly Contest 204
1568 Minimum Number of Days to Disconnect Island Depth-First Search,Breadth-First Search,Array,Matrix,Strongly Connected Component Hard Weekly Contest 204
1569 Number of Ways to Reorder Array to Get Same BST Tree,Union Find,Binary Search Tree,Memoization,Array,Math,Divide and Conquer,Dynamic Programming,Binary Tree,Combinatorics Hard Weekly Contest 204
1570 Dot Product of Two Sparse Vectors Design,Array,Hash Table,Two Pointers Medium ๐Ÿ”’
1571 Warehouse Manager Database Easy ๐Ÿ”’
1572 Matrix Diagonal Sum Array,Matrix Easy Biweekly Contest 34
1573 Number of Ways to Split a String Math,String Medium Biweekly Contest 34
1574 Shortest Subarray to be Removed to Make Array Sorted Stack,Array,Two Pointers,Binary Search,Monotonic Stack Medium Biweekly Contest 34
1575 Count All Possible Routes Memoization,Array,Dynamic Programming Hard Biweekly Contest 34
1576 Replace All 's to Avoid Consecutive Repeating Characters String Easy Weekly Contest 205
1577 Number of Ways Where Square of Number Is Equal to Product of Two Numbers Array,Hash Table,Math,Two Pointers Medium Weekly Contest 205
1578 Minimum Time to Make Rope Colorful Greedy,Array,String,Dynamic Programming Medium Weekly Contest 205
1579 Remove Max Number of Edges to Keep Graph Fully Traversable Union Find,Graph Hard Weekly Contest 205
1580 Put Boxes Into the Warehouse II Greedy,Array,Sorting Medium ๐Ÿ”’
1581 Customer Who Visited but Did Not Make Any Transactions Database Easy
1582 Special Positions in a Binary Matrix Array,Matrix Easy Weekly Contest 206
1583 Count Unhappy Friends Array,Simulation Medium Weekly Contest 206
1584 Min Cost to Connect All Points Union Find,Array,Minimum Spanning Tree Medium Weekly Contest 206
1585 Check If String Is Transformable With Substring Sort Operations Greedy,String,Sorting Hard Weekly Contest 206
1586 Binary Search Tree Iterator II Stack,Tree,Design,Binary Search Tree,Binary Tree,Iterator Medium ๐Ÿ”’
1587 Bank Account Summary II Database Easy
1588 Sum of All Odd Length Subarrays Array,Math,Prefix Sum Easy Biweekly Contest 35
1589 Maximum Sum Obtained of Any Permutation Greedy,Array,Prefix Sum,Sorting Medium Biweekly Contest 35
1590 Make Sum Divisible by P Array,Hash Table,Prefix Sum Medium Biweekly Contest 35
1591 Strange Printer II Graph,Topological Sort,Array,Matrix Hard Biweekly Contest 35
1592 Rearrange Spaces Between Words String Easy Weekly Contest 207
1593 Split a String Into the Max Number of Unique Substrings Hash Table,String,Backtracking Medium Weekly Contest 207
1594 Maximum Non Negative Product in a Matrix Array,Dynamic Programming,Matrix Medium Weekly Contest 207
1595 Minimum Cost to Connect Two Groups of Points Bit Manipulation,Array,Dynamic Programming,Bitmask,Matrix Hard Weekly Contest 207
1596 The Most Frequently Ordered Products for Each Customer Database Medium ๐Ÿ”’
1597 Build Binary Expression Tree From Infix Expression Stack,Tree,String,Binary Tree Hard ๐Ÿ”’
1598 Crawler Log Folder Stack,Array,String Easy Weekly Contest 208
1599 Maximum Profit of Operating a Centennial Wheel Array,Simulation Medium Weekly Contest 208
1600 Throne Inheritance Tree,Depth-First Search,Design,Hash Table Medium Weekly Contest 208
1601 Maximum Number of Achievable Transfer Requests Bit Manipulation,Array,Backtracking,Enumeration Hard Weekly Contest 208
1602 Find Nearest Right Node in Binary Tree Tree,Breadth-First Search,Binary Tree Medium ๐Ÿ”’
1603 Design Parking System Design,Counting,Simulation Easy Biweekly Contest 36
1604 Alert Using Same Key-Card Three or More Times in a One Hour Period Array,Hash Table,String,Sorting Medium Biweekly Contest 36
1605 Find Valid Matrix Given Row and Column Sums Greedy,Array,Matrix Medium Biweekly Contest 36
1606 Find Servers That Handled Most Number of Requests Greedy,Array,Ordered Set,Heap (Priority Queue) Hard Biweekly Contest 36
1607 Sellers With No Sales Database Easy ๐Ÿ”’
1608 Special Array With X Elements Greater Than or Equal X Array,Binary Search,Sorting Easy Weekly Contest 209
1609 Even Odd Tree Tree,Breadth-First Search,Binary Tree Medium Weekly Contest 209
1610 Maximum Number of Visible Points Geometry,Array,Math,Sorting,Sliding Window Hard Weekly Contest 209
1611 Minimum One Bit Operations to Make Integers Zero Bit Manipulation,Memoization,Dynamic Programming Hard Weekly Contest 209
1612 Check If Two Expression Trees are Equivalent Tree,Depth-First Search,Binary Tree Medium ๐Ÿ”’
1613 Find the Missing IDs Database Medium ๐Ÿ”’
1614 Maximum Nesting Depth of the Parentheses Stack,String Easy Weekly Contest 210
1615 Maximal Network Rank Graph Medium Weekly Contest 210
1616 Split Two Strings to Make Palindrome Greedy,Two Pointers,String Medium Weekly Contest 210
1617 Count Subtrees With Max Distance Between Cities Bit Manipulation,Tree,Dynamic Programming,Bitmask,Enumeration Hard Weekly Contest 210
1618 Maximum Font to Fit a Sentence in a Screen Array,String,Binary Search,Interactive Medium ๐Ÿ”’
1619 Mean of Array After Removing Some Elements Array,Sorting Easy Biweekly Contest 37
1620 Coordinate With Maximum Network Quality Array,Enumeration Medium Biweekly Contest 37
1621 Number of Sets of K Non-Overlapping Line Segments Math,Dynamic Programming Medium Biweekly Contest 37
1622 Fancy Sequence Design,Segment Tree,Math Hard Biweekly Contest 37
1623 All Valid Triplets That Can Represent a Country Database Easy ๐Ÿ”’
1624 Largest Substring Between Two Equal Characters Hash Table,String Easy Weekly Contest 211
1625 Lexicographically Smallest String After Applying Operations Breadth-First Search,String Medium Weekly Contest 211
1626 Best Team With No Conflicts Array,Dynamic Programming,Sorting Medium Weekly Contest 211
1627 Graph Connectivity With Threshold Union Find,Array,Math Hard Weekly Contest 211
1628 Design an Expression Tree With Evaluate Function Stack,Tree,Design,Math,Binary Tree Medium ๐Ÿ”’
1629 Slowest Key Array,String Easy Weekly Contest 212
1630 Arithmetic Subarrays Array,Sorting Medium Weekly Contest 212
1631 Path With Minimum Effort Depth-First Search,Breadth-First Search,Union Find,Array,Binary Search,Matrix,Heap (Priority Queue) Medium Weekly Contest 212
1632 Rank Transform of a Matrix Greedy,Union Find,Graph,Topological Sort,Array,Matrix Hard Weekly Contest 212
1633 Percentage of Users Attended a Contest Database Easy ๐Ÿ”’
1634 Add Two Polynomials Represented as Linked Lists Linked List,Math,Two Pointers Medium ๐Ÿ”’
1635 Hopper Company Queries I Database Hard ๐Ÿ”’
1636 Sort Array by Increasing Frequency Array,Hash Table,Sorting Easy Biweekly Contest 38
1637 Widest Vertical Area Between Two Points Containing No Points Array,Sorting Medium Biweekly Contest 38
1638 Count Substrings That Differ by One Character Hash Table,String,Dynamic Programming Medium Biweekly Contest 38
1639 Number of Ways to Form a Target String Given a Dictionary Array,String,Dynamic Programming Hard Biweekly Contest 38
1640 Check Array Formation Through Concatenation Array,Hash Table Easy Weekly Contest 213
1641 Count Sorted Vowel Strings Dynamic Programming Medium Weekly Contest 213
1642 Furthest Building You Can Reach Greedy,Array,Heap (Priority Queue) Medium Weekly Contest 213
1643 Kth Smallest Instructions Array,Math,Dynamic Programming,Combinatorics Hard Weekly Contest 213
1644 Lowest Common Ancestor of a Binary Tree II Tree,Depth-First Search,Binary Tree Medium ๐Ÿ”’
1645 Hopper Company Queries II Database Hard ๐Ÿ”’
1646 Get Maximum in Generated Array Array,Dynamic Programming,Simulation Easy Weekly Contest 214
1647 Minimum Deletions to Make Character Frequencies Unique Greedy,String,Sorting Medium Weekly Contest 214
1648 Sell Diminishing-Valued Colored Balls Greedy,Array,Math,Binary Search,Sorting,Heap (Priority Queue) Medium Weekly Contest 214
1649 Create Sorted Array through Instructions Binary Indexed Tree,Segment Tree,Array,Binary Search,Divide and Conquer,Ordered Set,Merge Sort Hard Weekly Contest 214
1650 Lowest Common Ancestor of a Binary Tree III Tree,Hash Table,Binary Tree Medium ๐Ÿ”’
1651 Hopper Company Queries III Database Hard ๐Ÿ”’
1652 Defuse the Bomb Array Easy Biweekly Contest 39
1653 Minimum Deletions to Make String Balanced Stack,String,Dynamic Programming Medium Biweekly Contest 39
1654 Minimum Jumps to Reach Home Breadth-First Search,Array,Dynamic Programming Medium Biweekly Contest 39
1655 Distribute Repeating Integers Bit Manipulation,Array,Dynamic Programming,Backtracking,Bitmask Hard Biweekly Contest 39
1656 Design an Ordered Stream Design,Array,Hash Table,Data Stream Easy Weekly Contest 215
1657 Determine if Two Strings Are Close Hash Table,String,Sorting Medium Weekly Contest 215
1658 Minimum Operations to Reduce X to Zero Array,Hash Table,Binary Search,Prefix Sum,Sliding Window Medium Weekly Contest 215
1659 Maximize Grid Happiness Bit Manipulation,Memoization,Dynamic Programming,Bitmask Hard Weekly Contest 215
1660 Correct a Binary Tree Tree,Depth-First Search,Breadth-First Search,Hash Table,Binary Tree Medium ๐Ÿ”’
1661 Average Time of Process per Machine Database Easy ๐Ÿ”’
1662 Check If Two String Arrays are Equivalent Array,String Easy Weekly Contest 216
1663 Smallest String With A Given Numeric Value Greedy,String Medium Weekly Contest 216
1664 Ways to Make a Fair Array Array,Dynamic Programming Medium Weekly Contest 216
1665 Minimum Initial Energy to Finish Tasks Greedy,Array,Sorting Hard Weekly Contest 216
1666 Change the Root of a Binary Tree Tree,Depth-First Search,Binary Tree Medium ๐Ÿ”’
1667 Fix Names in a Table Database Easy
1668 Maximum Repeating Substring String,String Matching Easy Biweekly Contest 40
1669 Merge In Between Linked Lists Linked List Medium Biweekly Contest 40
1670 Design Front Middle Back Queue Design,Queue,Array,Linked List,Data Stream Medium Biweekly Contest 40
1671 Minimum Number of Removals to Make Mountain Array Greedy,Array,Binary Search,Dynamic Programming Hard Biweekly Contest 40
1672 Richest Customer Wealth Array,Matrix Easy Weekly Contest 217
1673 Find the Most Competitive Subsequence Stack,Greedy,Array,Monotonic Stack Medium Weekly Contest 217
1674 Minimum Moves to Make Array Complementary Array,Hash Table,Prefix Sum Medium Weekly Contest 217
1675 Minimize Deviation in Array Greedy,Array,Ordered Set,Heap (Priority Queue) Hard Weekly Contest 217
1676 Lowest Common Ancestor of a Binary Tree IV Tree,Depth-First Search,Binary Tree Medium ๐Ÿ”’
1677 Product's Worth Over Invoices Database Easy ๐Ÿ”’
1678 Goal Parser Interpretation String Easy Weekly Contest 218
1679 Max Number of K-Sum Pairs Array,Hash Table,Two Pointers,Sorting Medium Weekly Contest 218
1680 Concatenation of Consecutive Binary Numbers Bit Manipulation,Math,Simulation Medium Weekly Contest 218
1681 Minimum Incompatibility Bit Manipulation,Array,Dynamic Programming,Bitmask Hard Weekly Contest 218
1682 Longest Palindromic Subsequence II String,Dynamic Programming Medium ๐Ÿ”’
1683 Invalid Tweets Database Easy ๐Ÿ”’
1684 Count the Number of Consistent Strings Bit Manipulation,Array,Hash Table,String Easy Biweekly Contest 41
1685 Sum of Absolute Differences in a Sorted Array Array,Math,Prefix Sum Medium Biweekly Contest 41
1686 Stone Game VI Greedy,Array,Math,Game Theory,Sorting,Heap (Priority Queue) Medium Biweekly Contest 41
1687 Delivering Boxes from Storage to Ports Segment Tree,Queue,Array,Dynamic Programming,Monotonic Queue,Heap (Priority Queue) Hard Biweekly Contest 41
1688 Count of Matches in Tournament Math,Simulation Easy Weekly Contest 219
1689 Partitioning Into Minimum Number Of Deci-Binary Numbers Greedy,String Medium Weekly Contest 219
1690 Stone Game VII Array,Math,Dynamic Programming,Game Theory Medium Weekly Contest 219
1691 Maximum Height by Stacking Cuboids Array,Dynamic Programming,Sorting Hard Weekly Contest 219
1692 Count Ways to Distribute Candies Dynamic Programming Hard ๐Ÿ”’
1693 Daily Leads and Partners Database Easy
1694 Reformat Phone Number String Easy Weekly Contest 220
1695 Maximum Erasure Value Array,Hash Table,Sliding Window Medium Weekly Contest 220
1696 Jump Game VI Queue,Array,Dynamic Programming,Sliding Window,Monotonic Queue,Heap (Priority Queue) Medium Weekly Contest 220
1697 Checking Existence of Edge Length Limited Paths Union Find,Graph,Array,Sorting Hard Weekly Contest 220
1698 Number of Distinct Substrings in a String Trie,String,Suffix Array,Hash Function,Rolling Hash Medium ๐Ÿ”’
1699 Number of Calls Between Two Persons Database Medium ๐Ÿ”’
1700 Number of Students Unable to Eat Lunch Stack,Queue,Array,Simulation Easy Biweekly Contest 42
1701 Average Waiting Time Array,Simulation Medium Biweekly Contest 42
1702 Maximum Binary String After Change Greedy,String Medium Biweekly Contest 42
1703 Minimum Adjacent Swaps for K Consecutive Ones Greedy,Array,Prefix Sum,Sliding Window Hard Biweekly Contest 42
1704 Determine if String Halves Are Alike String,Counting Easy Weekly Contest 221
1705 Maximum Number of Eaten Apples Greedy,Array,Heap (Priority Queue) Medium Weekly Contest 221
1706 Where Will the Ball Fall Depth-First Search,Array,Dynamic Programming,Matrix,Simulation Medium Weekly Contest 221
1707 Maximum XOR With an Element From Array Bit Manipulation,Trie,Array Hard Weekly Contest 221
1708 Largest Subarray Length K Greedy,Array Easy ๐Ÿ”’
1709 Biggest Window Between Visits Database Medium ๐Ÿ”’
1710 Maximum Units on a Truck Greedy,Array,Sorting Easy Weekly Contest 222
1711 Count Good Meals Array,Hash Table Medium Weekly Contest 222
1712 Ways to Split Array Into Three Subarrays Array,Two Pointers,Binary Search,Prefix Sum Medium Weekly Contest 222
1713 Minimum Operations to Make a Subsequence Greedy,Array,Hash Table,Binary Search Hard Weekly Contest 222
1714 Sum Of Special Evenly-Spaced Elements In Array Array,Dynamic Programming Hard ๐Ÿ”’
1715 Count Apples and Oranges Database Medium ๐Ÿ”’
1716 Calculate Money in Leetcode Bank Math Easy Biweekly Contest 43
1717 Maximum Score From Removing Substrings Stack,Greedy,String Medium Biweekly Contest 43
1718 Construct the Lexicographically Largest Valid Sequence Array,Backtracking Medium Biweekly Contest 43
1719 Number Of Ways To Reconstruct A Tree Tree,Graph,Topological Sort Hard Biweekly Contest 43
1720 Decode XORed Array Bit Manipulation,Array Easy Weekly Contest 223
1721 Swapping Nodes in a Linked List Linked List,Two Pointers Medium Weekly Contest 223
1722 Minimize Hamming Distance After Swap Operations Depth-First Search,Union Find,Array Medium Weekly Contest 223
1723 Find Minimum Time to Finish All Jobs Bit Manipulation,Array,Dynamic Programming,Backtracking,Bitmask Hard Weekly Contest 223
1724 Checking Existence of Edge Length Limited Paths II Union Find,Graph,Minimum Spanning Tree Hard ๐Ÿ”’
1725 Number Of Rectangles That Can Form The Largest Square Array Easy Weekly Contest 224
1726 Tuple with Same Product Array,Hash Table Medium Weekly Contest 224
1727 Largest Submatrix With Rearrangements Greedy,Array,Matrix,Sorting Medium Weekly Contest 224
1728 Cat and Mouse II Graph,Topological Sort,Memoization,Array,Math,Dynamic Programming,Game Theory,Matrix Hard Weekly Contest 224
1729 Find Followers Count Database Easy
1730 Shortest Path to Get Food Breadth-First Search,Array,Matrix Medium ๐Ÿ”’
1731 The Number of Employees Which Report to Each Employee Database Easy ๐Ÿ”’
1732 Find the Highest Altitude Array,Prefix Sum Easy Biweekly Contest 44
1733 Minimum Number of People to Teach Greedy,Array Medium Biweekly Contest 44
1734 Decode XORed Permutation Bit Manipulation,Array Medium Biweekly Contest 44
1735 Count Ways to Make Array With Product Array,Math,Dynamic Programming Hard Biweekly Contest 44
1736 Latest Time by Replacing Hidden Digits String Easy Weekly Contest 225
1737 Change Minimum Characters to Satisfy One of Three Conditions Hash Table,String,Counting,Prefix Sum Medium Weekly Contest 225
1738 Find Kth Largest XOR Coordinate Value Bit Manipulation,Array,Divide and Conquer,Matrix,Prefix Sum,Quickselect,Heap (Priority Queue) Medium Weekly Contest 225
1739 Building Boxes Greedy,Math,Binary Search Hard Weekly Contest 225
1740 Find Distance in a Binary Tree Tree,Depth-First Search,Breadth-First Search,Hash Table,Binary Tree Medium ๐Ÿ”’
1741 Find Total Time Spent by Each Employee Database Easy
1742 Maximum Number of Balls in a Box Hash Table,Math,Counting Easy Weekly Contest 226
1743 Restore the Array From Adjacent Pairs Array,Hash Table Medium Weekly Contest 226
1744 Can You Eat Your Favorite Candy on Your Favorite Day Array,Prefix Sum Medium Weekly Contest 226
1745 Palindrome Partitioning IV String,Dynamic Programming Hard Weekly Contest 226
1746 Maximum Subarray Sum After One Operation Array,Dynamic Programming Medium ๐Ÿ”’
1747 Leetflex Banned Accounts Database Medium ๐Ÿ”’
1748 Sum of Unique Elements Array,Hash Table,Counting Easy Biweekly Contest 45
1749 Maximum Absolute Sum of Any Subarray Array,Dynamic Programming Medium Biweekly Contest 45
1750 Minimum Length of String After Deleting Similar Ends Two Pointers,String Medium Biweekly Contest 45
1751 Maximum Number of Events That Can Be Attended II Array,Binary Search,Dynamic Programming Hard Biweekly Contest 45
1752 Check if Array Is Sorted and Rotated Array Easy Weekly Contest 227
1753 Maximum Score From Removing Stones Greedy,Math,Heap (Priority Queue) Medium Weekly Contest 227
1754 Largest Merge Of Two Strings Greedy,Two Pointers,String Medium Weekly Contest 227
1755 Closest Subsequence Sum Bit Manipulation,Array,Two Pointers,Dynamic Programming,Bitmask Hard Weekly Contest 227
1756 Design Most Recently Used Queue Stack,Design,Binary Indexed Tree,Array,Hash Table,Ordered Set Medium ๐Ÿ”’
1757 Recyclable and Low Fat Products Database Easy
1758 Minimum Changes To Make Alternating Binary String String Easy Weekly Contest 228
1759 Count Number of Homogenous Substrings Math,String Medium Weekly Contest 228
1760 Minimum Limit of Balls in a Bag Array,Binary Search Medium Weekly Contest 228
1761 Minimum Degree of a Connected Trio in a Graph Graph Hard Weekly Contest 228
1762 Buildings With an Ocean View Stack,Array,Monotonic Stack Medium ๐Ÿ”’
1763 Longest Nice Substring Bit Manipulation,Hash Table,String,Sliding Window Easy Biweekly Contest 46
1764 Form Array by Concatenating Subarrays of Another Array Greedy,Array,String Matching Medium Biweekly Contest 46
1765 Map of Highest Peak Breadth-First Search,Array,Matrix Medium Biweekly Contest 46
1766 Tree of Coprimes Tree,Depth-First Search,Breadth-First Search,Math Hard Biweekly Contest 46
1767 Find the Subtasks That Did Not Execute Database Hard ๐Ÿ”’
1768 Merge Strings Alternately Two Pointers,String Easy Weekly Contest 229
1769 Minimum Number of Operations to Move All Balls to Each Box Array,String Medium Weekly Contest 229
1770 Maximum Score from Performing Multiplication Operations Array,Dynamic Programming Medium Weekly Contest 229
1771 Maximize Palindrome Length From Subsequences String,Dynamic Programming Hard Weekly Contest 229
1772 Sort Features by Popularity Array,Hash Table,String,Sorting Medium ๐Ÿ”’
1773 Count Items Matching a Rule Array,String Easy Weekly Contest 230
1774 Closest Dessert Cost Array,Dynamic Programming,Backtracking Medium Weekly Contest 230
1775 Equal Sum Arrays With Minimum Number of Operations Greedy,Array,Hash Table,Counting Medium Weekly Contest 230
1776 Car Fleet II Stack,Array,Math,Monotonic Stack,Heap (Priority Queue) Hard Weekly Contest 230
1777 Product's Price for Each Store Database Easy ๐Ÿ”’
1778 Shortest Path in a Hidden Grid Depth-First Search,Breadth-First Search,Graph,Interactive Medium ๐Ÿ”’
1779 Find Nearest Point That Has the Same X or Y Coordinate Array Easy Biweekly Contest 47
1780 Check if Number is a Sum of Powers of Three Math Medium Biweekly Contest 47
1781 Sum of Beauty of All Substrings Hash Table,String,Counting Medium Biweekly Contest 47
1782 Count Pairs Of Nodes Graph,Two Pointers,Binary Search Hard Biweekly Contest 47
1783 Grand Slam Titles Database Medium ๐Ÿ”’
1784 Check if Binary String Has at Most One Segment of Ones String Easy Weekly Contest 231
1785 Minimum Elements to Add to Form a Given Sum Greedy,Array Medium Weekly Contest 231
1786 Number of Restricted Paths From First to Last Node Graph,Topological Sort,Dynamic Programming,Shortest Path,Heap (Priority Queue) Medium Weekly Contest 231
1787 Make the XOR of All Segments Equal to Zero Bit Manipulation,Array,Dynamic Programming Hard Weekly Contest 231
1788 Maximize the Beauty of the Garden Greedy,Array,Prefix Sum Hard ๐Ÿ”’
1789 Primary Department for Each Employee Database Easy ๐Ÿ”’
1790 Check if One String Swap Can Make Strings Equal Hash Table,String,Counting Easy Weekly Contest 232
1791 Find Center of Star Graph Graph Easy Weekly Contest 232
1792 Maximum Average Pass Ratio Greedy,Array,Heap (Priority Queue) Medium Weekly Contest 232
1793 Maximum Score of a Good Subarray Stack,Array,Two Pointers,Binary Search,Monotonic Stack Hard Weekly Contest 232
1794 Count Pairs of Equal Substrings With Minimum Difference Greedy,Hash Table,String Medium ๐Ÿ”’
1795 Rearrange Products Table Database Easy
1796 Second Largest Digit in a String Hash Table,String Easy Biweekly Contest 48
1797 Design Authentication Manager Design,Hash Table Medium Biweekly Contest 48
1798 Maximum Number of Consecutive Values You Can Make Greedy,Array Medium Biweekly Contest 48
1799 Maximize Score After N Operations Bit Manipulation,Array,Math,Dynamic Programming,Backtracking,Bitmask,Number Theory Hard Biweekly Contest 48
1800 Maximum Ascending Subarray Sum Array Easy Weekly Contest 233
1801 Number of Orders in the Backlog Array,Simulation,Heap (Priority Queue) Medium Weekly Contest 233
1802 Maximum Value at a Given Index in a Bounded Array Greedy,Binary Search Medium Weekly Contest 233
1803 Count Pairs With XOR in a Range Bit Manipulation,Trie,Array Hard Weekly Contest 233
1804 Implement Trie II (Prefix Tree) Design,Trie,Hash Table,String Medium ๐Ÿ”’
1805 Number of Different Integers in a String Hash Table,String Easy Weekly Contest 234
1806 Minimum Number of Operations to Reinitialize a Permutation Array,Math,Simulation Medium Weekly Contest 234
1807 Evaluate the Bracket Pairs of a String Array,Hash Table,String Medium Weekly Contest 234
1808 Maximize Number of Nice Divisors Recursion,Math Hard Weekly Contest 234
1809 Ad-Free Sessions Database Easy ๐Ÿ”’
1810 Minimum Path Cost in a Hidden Grid Depth-First Search,Breadth-First Search,Graph,Interactive,Heap (Priority Queue) Medium ๐Ÿ”’
1811 Find Interview Candidates Database Medium ๐Ÿ”’
1812 Determine Color of a Chessboard Square Math,String Easy Biweekly Contest 49
1813 Sentence Similarity III Array,Two Pointers,String Medium Biweekly Contest 49
1814 Count Nice Pairs in an Array Array,Hash Table,Math,Counting Medium Biweekly Contest 49
1815 Maximum Number of Groups Getting Fresh Donuts Bit Manipulation,Memoization,Array,Dynamic Programming,Bitmask Hard Biweekly Contest 49
1816 Truncate Sentence Array,String Easy Weekly Contest 235
1817 Finding the Users Active Minutes Array,Hash Table Medium Weekly Contest 235
1818 Minimum Absolute Sum Difference Array,Binary Search,Ordered Set,Sorting Medium Weekly Contest 235
1819 Number of Different Subsequences GCDs Array,Math,Counting,Number Theory Hard Weekly Contest 235
1820 Maximum Number of Accepted Invitations Array,Backtracking,Matrix Medium ๐Ÿ”’
1821 Find Customers With Positive Revenue this Year Database Easy ๐Ÿ”’
1822 Sign of the Product of an Array Array,Math Easy Weekly Contest 236
1823 Find the Winner of the Circular Game Recursion,Queue,Array,Math,Simulation Medium Weekly Contest 236
1824 Minimum Sideway Jumps Greedy,Array,Dynamic Programming Medium Weekly Contest 236
1825 Finding MK Average Design,Queue,Ordered Set,Heap (Priority Queue) Hard Weekly Contest 236
1826 Faulty Sensor Array,Two Pointers Easy ๐Ÿ”’
1827 Minimum Operations to Make the Array Increasing Greedy,Array Easy Biweekly Contest 50
1828 Queries on Number of Points Inside a Circle Geometry,Array,Math Medium Biweekly Contest 50
1829 Maximum XOR for Each Query Bit Manipulation,Array,Prefix Sum Medium Biweekly Contest 50
1830 Minimum Number of Operations to Make String Sorted Math,String,Combinatorics Hard Biweekly Contest 50
1831 Maximum Transaction Each Day Database Medium ๐Ÿ”’
1832 Check if the Sentence Is Pangram Hash Table,String Easy Weekly Contest 237
1833 Maximum Ice Cream Bars Greedy,Array,Sorting Medium Weekly Contest 237
1834 Single-Threaded CPU Array,Sorting,Heap (Priority Queue) Medium Weekly Contest 237
1835 Find XOR Sum of All Pairs Bitwise AND Bit Manipulation,Array,Math Hard Weekly Contest 237
1836 Remove Duplicates From an Unsorted Linked List Hash Table,Linked List Medium ๐Ÿ”’
1837 Sum of Digits in Base K Math Easy Weekly Contest 238
1838 Frequency of the Most Frequent Element Array,Binary Search,Prefix Sum,Sliding Window Medium Weekly Contest 238
1839 Longest Substring Of All Vowels in Order String,Sliding Window Medium Weekly Contest 238
1840 Maximum Building Height Array,Math Hard Weekly Contest 238
1841 League Statistics Database Medium ๐Ÿ”’
1842 Next Palindrome Using Same Digits Two Pointers,String Hard ๐Ÿ”’
1843 Suspicious Bank Accounts Database Medium ๐Ÿ”’
1844 Replace All Digits with Characters String Easy Biweekly Contest 51
1845 Seat Reservation Manager Design,Heap (Priority Queue) Medium Biweekly Contest 51
1846 Maximum Element After Decreasing and Rearranging Greedy,Array,Sorting Medium Biweekly Contest 51
1847 Closest Room Array,Binary Search,Sorting Hard Biweekly Contest 51
1848 Minimum Distance to the Target Element Array Easy Weekly Contest 239
1849 Splitting a String Into Descending Consecutive Values String,Backtracking Medium Weekly Contest 239
1850 Minimum Adjacent Swaps to Reach the Kth Smallest Number Greedy,Two Pointers,String Medium Weekly Contest 239
1851 Minimum Interval to Include Each Query Array,Binary Search,Sorting,Line Sweep,Heap (Priority Queue) Hard Weekly Contest 239
1852 Distinct Numbers in Each Subarray Array,Hash Table,Sliding Window Medium ๐Ÿ”’
1853 Convert Date Format Database Easy ๐Ÿ”’
1854 Maximum Population Year Array,Counting Easy Weekly Contest 240
1855 Maximum Distance Between a Pair of Values Greedy,Array,Two Pointers,Binary Search Medium Weekly Contest 240
1856 Maximum Subarray Min-Product Stack,Array,Prefix Sum,Monotonic Stack Medium Weekly Contest 240
1857 Largest Color Value in a Directed Graph Graph,Topological Sort,Memoization,Hash Table,Dynamic Programming,Counting Hard Weekly Contest 240
1858 Longest Word With All Prefixes Depth-First Search,Trie Medium ๐Ÿ”’
1859 Sorting the Sentence String,Sorting Easy Biweekly Contest 52
1860 Incremental Memory Leak Simulation Medium Biweekly Contest 52
1861 Rotating the Box Array,Two Pointers,Matrix Medium Biweekly Contest 52
1862 Sum of Floored Pairs Array,Math,Binary Search,Prefix Sum Hard Biweekly Contest 52
1863 Sum of All Subset XOR Totals Bit Manipulation,Array,Math,Backtracking,Combinatorics Easy Weekly Contest 241
1864 Minimum Number of Swaps to Make the Binary String Alternating Greedy,String Medium Weekly Contest 241
1865 Finding Pairs With a Certain Sum Design,Array,Hash Table Medium Weekly Contest 241
1866 Number of Ways to Rearrange Sticks With K Sticks Visible Math,Dynamic Programming,Combinatorics Hard Weekly Contest 241
1867 Orders With Maximum Quantity Above Average Database Medium ๐Ÿ”’
1868 Product of Two Run-Length Encoded Arrays Array,Two Pointers Medium ๐Ÿ”’
1869 Longer Contiguous Segments of Ones than Zeros String Easy Weekly Contest 242
1870 Minimum Speed to Arrive on Time Array,Binary Search Medium Weekly Contest 242
1871 Jump Game VII Two Pointers,String,Prefix Sum Medium Weekly Contest 242
1872 Stone Game VIII Array,Math,Dynamic Programming,Game Theory,Prefix Sum Hard Weekly Contest 242
1873 Calculate Special Bonus Database Easy
1874 Minimize Product Sum of Two Arrays Greedy,Array,Sorting Medium ๐Ÿ”’
1875 Group Employees of the Same Salary Database Medium ๐Ÿ”’
1876 Substrings of Size Three with Distinct Characters Hash Table,String,Counting,Sliding Window Easy Biweekly Contest 53
1877 Minimize Maximum Pair Sum in Array Greedy,Array,Two Pointers,Sorting Medium Biweekly Contest 53
1878 Get Biggest Three Rhombus Sums in a Grid Array,Math,Matrix,Prefix Sum,Sorting,Heap (Priority Queue) Medium Biweekly Contest 53
1879 Minimum XOR Sum of Two Arrays Bit Manipulation,Array,Dynamic Programming,Bitmask Hard Biweekly Contest 53
1880 Check if Word Equals Summation of Two Words String Easy Weekly Contest 243
1881 Maximum Value after Insertion Greedy,String Medium Weekly Contest 243
1882 Process Tasks Using Servers Array,Heap (Priority Queue) Medium Weekly Contest 243
1883 Minimum Skips to Arrive at Meeting On Time Array,Dynamic Programming Hard Weekly Contest 243
1884 Egg Drop With 2 Eggs and N Floors Math,Dynamic Programming Medium
1885 Count Pairs in Two Arrays Array,Binary Search,Sorting Medium ๐Ÿ”’
1886 Determine Whether Matrix Can Be Obtained By Rotation Array,Matrix Easy Weekly Contest 244
1887 Reduction Operations to Make the Array Elements Equal Array,Sorting Medium Weekly Contest 244
1888 Minimum Number of Flips to Make the Binary String Alternating Greedy,String Medium Weekly Contest 244
1889 Minimum Space Wasted From Packaging Array,Binary Search,Prefix Sum,Sorting Hard Weekly Contest 244
1890 The Latest Login in 2020 Database Easy
1891 Cutting Ribbons Array,Binary Search Medium ๐Ÿ”’
1892 Page Recommendations II Database Hard ๐Ÿ”’
1893 Check if All the Integers in a Range Are Covered Array,Hash Table,Prefix Sum Easy Biweekly Contest 54
1894 Find the Student that Will Replace the Chalk Array,Binary Search,Prefix Sum,Simulation Medium Biweekly Contest 54
1895 Largest Magic Square Array,Matrix,Prefix Sum Medium Biweekly Contest 54
1896 Minimum Cost to Change the Final Value of Expression Stack,Math,String,Dynamic Programming Hard Biweekly Contest 54
1897 Redistribute Characters to Make All Strings Equal Hash Table,String,Counting Easy Weekly Contest 245
1898 Maximum Number of Removable Characters Array,String,Binary Search Medium Weekly Contest 245
1899 Merge Triplets to Form Target Triplet Greedy,Array Medium Weekly Contest 245
1900 The Earliest and Latest Rounds Where Players Compete Memoization,Dynamic Programming Hard Weekly Contest 245
1901 Find a Peak Element II Array,Binary Search,Matrix Medium
1902 Depth of BST Given Insertion Order Tree,Binary Search Tree,Binary Tree,Ordered Set Medium ๐Ÿ”’
1903 Largest Odd Number in String Greedy,Math,String Easy Weekly Contest 246
1904 The Number of Full Rounds You Have Played Math,String Medium Weekly Contest 246
1905 Count Sub Islands Depth-First Search,Breadth-First Search,Union Find,Array,Matrix Medium Weekly Contest 246
1906 Minimum Absolute Difference Queries Array,Hash Table Medium Weekly Contest 246
1907 Count Salary Categories Database Medium ๐Ÿ”’
1908 Game of Nim Bit Manipulation,Brainteaser,Array,Math,Dynamic Programming,Game Theory Medium ๐Ÿ”’
1909 Remove One Element to Make the Array Strictly Increasing Array Easy Biweekly Contest 55
1910 Remove All Occurrences of a Substring String Medium Biweekly Contest 55
1911 Maximum Alternating Subsequence Sum Array,Dynamic Programming Medium Biweekly Contest 55
1912 Design Movie Rental System Design,Array,Hash Table,Ordered Set,Heap (Priority Queue) Hard Biweekly Contest 55
1913 Maximum Product Difference Between Two Pairs Array,Sorting Easy Weekly Contest 247
1914 Cyclically Rotating a Grid Array,Matrix,Simulation Medium Weekly Contest 247
1915 Number of Wonderful Substrings Bit Manipulation,Hash Table,String,Prefix Sum Medium Weekly Contest 247
1916 Count Ways to Build Rooms in an Ant Colony Tree,Graph,Topological Sort,Math,Dynamic Programming,Combinatorics Hard Weekly Contest 247
1917 Leetcodify Friends Recommendations Database Hard ๐Ÿ”’
1918 Kth Smallest Subarray Sum Array,Binary Search,Sliding Window Medium ๐Ÿ”’
1919 Leetcodify Similar Friends Database Hard ๐Ÿ”’
1920 Build Array from Permutation Array,Simulation Easy Weekly Contest 248
1921 Eliminate Maximum Number of Monsters Greedy,Array,Sorting Medium Weekly Contest 248
1922 Count Good Numbers Recursion,Math Medium Weekly Contest 248
1923 Longest Common Subpath Array,Binary Search,Suffix Array,Hash Function,Rolling Hash Hard Weekly Contest 248
1924 Erect the Fence II Geometry,Array,Math Hard ๐Ÿ”’
1925 Count Square Sum Triples Math,Enumeration Easy Biweekly Contest 56
1926 Nearest Exit from Entrance in Maze Breadth-First Search,Array,Matrix Medium Biweekly Contest 56
1927 Sum Game Greedy,Math,Game Theory Medium Biweekly Contest 56
1928 Minimum Cost to Reach Destination in Time Graph,Dynamic Programming Hard Biweekly Contest 56
1929 Concatenation of Array Array Easy Weekly Contest 249
1930 Unique Length-3 Palindromic Subsequences Hash Table,String,Prefix Sum Medium Weekly Contest 249
1931 Painting a Grid With Three Different Colors Dynamic Programming Hard Weekly Contest 249
1932 Merge BSTs to Create Single BST Tree,Depth-First Search,Hash Table,Binary Search,Binary Tree Hard Weekly Contest 249
1933 Check if String Is Decomposable Into Value-Equal Substrings String Easy ๐Ÿ”’
1934 Confirmation Rate Database Medium ๐Ÿ”’
1935 Maximum Number of Words You Can Type Hash Table,String Easy Weekly Contest 250
1936 Add Minimum Number of Rungs Greedy,Array Medium Weekly Contest 250
1937 Maximum Number of Points with Cost Medium Weekly Contest 250
1938 Maximum Genetic Difference Query Hard Weekly Contest 250
1939 Users That Actively Request Confirmation Messages Database Easy ๐Ÿ”’
1940 Longest Common Subsequence Between Sorted Arrays Array,Hash Table,Counting Medium ๐Ÿ”’
1941 Check if All Characters Have Equal Number of Occurrences Hash Table,String,Counting Easy Biweekly Contest 57
1942 The Number of the Smallest Unoccupied Chair Array,Ordered Set,Heap (Priority Queue) Medium Biweekly Contest 57
1943 Describe the Painting Array,Prefix Sum Medium Biweekly Contest 57
1944 Number of Visible People in a Queue Stack,Array,Monotonic Stack Hard Biweekly Contest 57
1945 Sum of Digits of String After Convert String,Simulation Easy Weekly Contest 251
1946 Largest Number After Mutating Substring Greedy,Array,String Medium Weekly Contest 251
1947 Maximum Compatibility Score Sum Bit Manipulation,Array,Dynamic Programming,Backtracking,Bitmask Medium Weekly Contest 251
1948 Delete Duplicate Folders in System Trie,Array,Hash Table,String,Hash Function Hard Weekly Contest 251
1949 Strong Friendship Database Medium ๐Ÿ”’
1950 Maximum of Minimum Values in All Subarrays Stack,Array,Monotonic Stack Medium ๐Ÿ”’
1951 All the Pairs With the Maximum Number of Common Followers Database Medium ๐Ÿ”’
1952 Three Divisors Math Easy Weekly Contest 252
1953 Maximum Number of Weeks for Which You Can Work Greedy,Array Medium Weekly Contest 252
1954 Minimum Garden Perimeter to Collect Enough Apples Math,Binary Search Medium Weekly Contest 252
1955 Count Number of Special Subsequences Array,Dynamic Programming Hard Weekly Contest 252
1956 Minimum Time For K Virus Variants to Spread Geometry,Array,Math,Binary Search,Enumeration Hard ๐Ÿ”’
1957 Delete Characters to Make Fancy String String Easy Biweekly Contest 58
1958 Check if Move is Legal Array,Enumeration,Matrix Medium Biweekly Contest 58
1959 Minimum Total Space Wasted With K Resizing Operations Array,Dynamic Programming Medium Biweekly Contest 58
1960 Maximum Product of the Length of Two Palindromic Substrings String,Hash Function,Rolling Hash Hard Biweekly Contest 58
1961 Check If String Is a Prefix of Array Array,String Easy Weekly Contest 253
1962 Remove Stones to Minimize the Total Array,Heap (Priority Queue) Medium Weekly Contest 253
1963 Minimum Number of Swaps to Make the String Balanced Stack,Greedy,Two Pointers,String Medium Weekly Contest 253
1964 Find the Longest Valid Obstacle Course at Each Position Binary Indexed Tree,Array,Binary Search Hard Weekly Contest 253
1965 Employees With Missing Information Database Easy
1966 Binary Searchable Numbers in an Unsorted Array Array,Binary Search Medium ๐Ÿ”’
1967 Number of Strings That Appear as Substrings in Word String Easy Weekly Contest 254
1968 Array With Elements Not Equal to Average of Neighbors Greedy,Array,Sorting Medium Weekly Contest 254
1969 Minimum Non-Zero Product of the Array Elements Greedy,Recursion,Math Medium Weekly Contest 254
1970 Last Day Where You Can Still Cross Depth-First Search,Breadth-First Search,Union Find,Array,Binary Search,Matrix Hard Weekly Contest 254
1971 Find if Path Exists in Graph Depth-First Search,Breadth-First Search,Graph Easy
1972 First and Last Call On the Same Day Database Hard ๐Ÿ”’
1973 Count Nodes Equal to Sum of Descendants Medium ๐Ÿ”’
1974 Minimum Time to Type Word Using Special Typewriter Greedy,String Easy Biweekly Contest 59
1975 Maximum Matrix Sum Greedy,Array,Matrix Medium Biweekly Contest 59
1976 Number of Ways to Arrive at Destination Graph,Topological Sort,Dynamic Programming,Shortest Path Medium Biweekly Contest 59
1977 Number of Ways to Separate Numbers String,Dynamic Programming,Suffix Array Hard Biweekly Contest 59
1978 Employees Whose Manager Left the Company Easy ๐Ÿ”’
1979 Find Greatest Common Divisor of Array Array,Math,Number Theory Easy Weekly Contest 255
1980 Find Unique Binary String Array,String,Backtracking Medium Weekly Contest 255
1981 Minimize the Difference Between Target and Chosen Elements Array,Dynamic Programming,Matrix Medium Weekly Contest 255
1982 Find Array Given Subset Sums Array,Divide and Conquer Hard Weekly Contest 255
1983 Widest Pair of Indices With Equal Range Sum Medium ๐Ÿ”’
1984 Minimum Difference Between Highest and Lowest of K Scores Array,Sorting,Sliding Window Easy Weekly Contest 256
1985 Find the Kth Largest Integer in the Array Array,String,Divide and Conquer,Quickselect,Sorting,Heap (Priority Queue) Medium Weekly Contest 256
1986 Minimum Number of Work Sessions to Finish the Tasks Bit Manipulation,Array,Dynamic Programming,Backtracking,Bitmask Medium Weekly Contest 256
1987 Number of Unique Good Subsequences String,Dynamic Programming Hard Weekly Contest 256
1988 Find Cutoff Score for Each School Medium ๐Ÿ”’
1989 Maximum Number of People That Can Be Caught in Tag Medium ๐Ÿ”’
1990 Count the Number of Experiments Easy ๐Ÿ”’
1991 Find the Middle Index in Array Array,Prefix Sum Easy Biweekly Contest 60
1992 Find All Groups of Farmland Depth-First Search,Breadth-First Search,Array,Matrix Medium Biweekly Contest 60
1993 Operations on Tree Tree,Depth-First Search,Breadth-First Search,Design,Hash Table Medium Biweekly Contest 60
1994 The Number of Good Subsets Bit Manipulation,Array,Math,Dynamic Programming,Bitmask Hard Biweekly Contest 60
1995 Count Special Quadruplets Array,Enumeration Easy Weekly Contest 257
1996 The Number of Weak Characters in the Game Stack,Greedy,Array,Sorting,Monotonic Stack Medium Weekly Contest 257
1997 First Day Where You Have Been in All the Rooms Array,Dynamic Programming Medium Weekly Contest 257
1998 GCD Sort of an Array Union Find,Array,Math,Sorting Hard Weekly Contest 257
1999 Smallest Greater Multiple Made of Two Digits Medium ๐Ÿ”’
2000 Reverse Prefix of Word Two Pointers,String Easy Weekly Contest 258
2001 Number of Pairs of Interchangeable Rectangles Array,Hash Table,Math,Counting,Number Theory Medium Weekly Contest 258
2002 Maximum Product of the Length of Two Palindromic Subsequences Bit Manipulation,String,Dynamic Programming,Backtracking,Bitmask Medium Weekly Contest 258
2003 Smallest Missing Genetic Value in Each Subtree Tree,Depth-First Search,Union Find,Dynamic Programming Hard Weekly Contest 258
2004 The Number of Seniors and Juniors to Join the Company Hard ๐Ÿ”’
2005 Subtree Removal Game with Fibonacci Tree Hard ๐Ÿ”’
2006 Count Number of Pairs With Absolute Difference K Array,Hash Table,Counting Easy Biweekly Contest 61
2007 Find Original Array From Doubled Array Greedy,Array,Hash Table,Sorting Medium Biweekly Contest 61
2008 Maximum Earnings From Taxi Array,Binary Search,Dynamic Programming,Sorting Medium Biweekly Contest 61
2009 Minimum Number of Operations to Make Array Continuous Array,Binary Search Hard Biweekly Contest 61
2010 The Number of Seniors and Juniors to Join the Company II Hard ๐Ÿ”’
2011 Final Value of Variable After Performing Operations Array,String,Simulation Easy Weekly Contest 259
2012 Sum of Beauty in the Array Array Medium Weekly Contest 259
2013 Detect Squares Design,Array,Hash Table,Counting Medium Weekly Contest 259
2014 Longest Subsequence Repeated k Times Greedy,String,Backtracking,Counting,Enumeration Hard Weekly Contest 259
2015 Average Height of Buildings in Each Segment Greedy,Array,Sorting,Heap (Priority Queue) Medium ๐Ÿ”’
2016 Maximum Difference Between Increasing Elements Array Easy Weekly Contest 260
2017 Grid Game Array,Matrix,Prefix Sum Medium Weekly Contest 260
2018 Check if Word Can Be Placed In Crossword Array,Enumeration,Matrix Medium Weekly Contest 260
2019 The Score of Students Solving Math Expression Stack,Memoization,Array,Math,String,Dynamic Programming Hard Weekly Contest 260
2020 Number of Accounts That Did Not Stream Database Medium ๐Ÿ”’
2021 Brightest Position on Street Array,Ordered Set,Prefix Sum Medium ๐Ÿ”’
2022 Convert 1D Array Into 2D Array Array,Matrix,Simulation Easy Biweekly Contest 62
2023 Number of Pairs of Strings With Concatenation Equal to Target Array,String Medium Biweekly Contest 62
2024 Maximize the Confusion of an Exam String,Binary Search,Prefix Sum,Sliding Window Medium Biweekly Contest 62
2025 Maximum Number of Ways to Partition an Array Array,Hash Table,Counting,Enumeration,Prefix Sum Hard Biweekly Contest 62
2026 Low-Quality Problems Database Easy ๐Ÿ”’
2027 Minimum Moves to Convert String Greedy,String Easy Weekly Contest 261
2028 Find Missing Observations Array,Math,Simulation Medium Weekly Contest 261
2029 Stone Game IX Greedy,Array,Math,Counting,Game Theory Medium Weekly Contest 261
2030 Smallest K-Length Subsequence With Occurrences of a Letter Stack,Greedy,String,Monotonic Stack Hard Weekly Contest 261
2031 Count Subarrays With More Ones Than Zeros Binary Indexed Tree,Segment Tree,Array,Binary Search,Divide and Conquer,Ordered Set,Merge Sort Medium ๐Ÿ”’
2032 Two Out of Three Array,Hash Table Easy Weekly Contest 262
2033 Minimum Operations to Make a Uni-Value Grid Array,Math,Matrix,Sorting Medium Weekly Contest 262
2034 Stock Price Fluctuation Design,Hash Table,Data Stream,Ordered Set,Heap (Priority Queue) Medium Weekly Contest 262
2035 Partition Array Into Two Arrays to Minimize Sum Difference Bit Manipulation,Array,Two Pointers,Binary Search,Dynamic Programming,Bitmask,Ordered Set Hard Weekly Contest 262
2036 Maximum Alternating Subarray Sum Array,Dynamic Programming Medium ๐Ÿ”’
2037 Minimum Number of Moves to Seat Everyone Array,Sorting Easy Biweekly Contest 63
2038 Remove Colored Pieces if Both Neighbors are the Same Color Greedy,Math,String,Game Theory Medium Biweekly Contest 63
2039 The Time When the Network Becomes Idle Breadth-First Search,Graph,Array Medium Biweekly Contest 63
2040 Kth Smallest Product of Two Sorted Arrays Array,Binary Search Hard Biweekly Contest 63
2041 Accepted Candidates From the Interviews Database Medium ๐Ÿ”’
2042 Check if Numbers Are Ascending in a Sentence String Easy Weekly Contest 263
2043 Simple Bank System Design,Array,Hash Table,Simulation Medium Weekly Contest 263
2044 Count Number of Maximum Bitwise-OR Subsets Bit Manipulation,Array,Backtracking Medium Weekly Contest 263
2045 Second Minimum Time to Reach Destination Breadth-First Search,Graph,Shortest Path Hard Weekly Contest 263
2046 Sort Linked List Already Sorted Using Absolute Values Linked List,Two Pointers,Sorting Medium ๐Ÿ”’
2047 Number of Valid Words in a Sentence String Easy Weekly Contest 264
2048 Next Greater Numerically Balanced Number Math,Backtracking,Enumeration Medium Weekly Contest 264
2049 Count Nodes With the Highest Score Tree,Depth-First Search,Array,Binary Tree Medium Weekly Contest 264
2050 Parallel Courses III Graph,Topological Sort,Dynamic Programming Hard Weekly Contest 264
2051 The Category of Each Member in the Store Database Medium ๐Ÿ”’
2052 Minimum Cost to Separate Sentence Into Rows Array,Dynamic Programming Medium ๐Ÿ”’
2053 Kth Distinct String in an Array Array,Hash Table,String,Counting Easy Biweekly Contest 64
2054 Two Best Non-Overlapping Events Array,Binary Search,Dynamic Programming,Sorting,Heap (Priority Queue) Medium Biweekly Contest 64
2055 Plates Between Candles Array,String,Binary Search,Prefix Sum Medium Biweekly Contest 64
2056 Number of Valid Move Combinations On Chessboard Array,String,Backtracking,Simulation Hard Biweekly Contest 64
2057 Smallest Index With Equal Value Array Easy Weekly Contest 265
2058 Find the Minimum and Maximum Number of Nodes Between Critical Points Linked List Medium Weekly Contest 265
2059 Minimum Operations to Convert Number Breadth-First Search,Array Medium Weekly Contest 265
2060 Check if an Original String Exists Given Two Encoded Strings String,Dynamic Programming Hard Weekly Contest 265
2061 Number of Spaces Cleaning Robot Cleaned Array,Matrix,Simulation Medium ๐Ÿ”’
2062 Count Vowel Substrings of a String Hash Table,String Easy Weekly Contest 266
2063 Vowels of All Substrings Math,String,Dynamic Programming,Combinatorics Medium Weekly Contest 266
2064 Minimized Maximum of Products Distributed to Any Store Array,Binary Search Medium Weekly Contest 266
2065 Maximum Path Quality of a Graph Graph,Array,Backtracking Hard Weekly Contest 266
2066 Account Balance Database Medium ๐Ÿ”’
2067 Number of Equal Count Substrings String,Counting,Prefix Sum Medium ๐Ÿ”’
2068 Check Whether Two Strings are Almost Equivalent Hash Table,String,Counting Easy Biweekly Contest 65
2069 Walking Robot Simulation II Design,Simulation Medium Biweekly Contest 65
2070 Most Beautiful Item for Each Query Array,Binary Search,Sorting Medium Biweekly Contest 65
2071 Maximum Number of Tasks You Can Assign Greedy,Queue,Array,Binary Search,Sorting,Monotonic Queue Hard Biweekly Contest 65
2072 The Winner University Database Easy ๐Ÿ”’
2073 Time Needed to Buy Tickets Queue,Array,Simulation Easy Weekly Contest 267
2074 Reverse Nodes in Even Length Groups Linked List Medium Weekly Contest 267
2075 Decode the Slanted Ciphertext String,Simulation Medium Weekly Contest 267
2076 Process Restricted Friend Requests Union Find,Graph Hard Weekly Contest 267
2077 Paths in Maze That Lead to Same Room Graph Medium ๐Ÿ”’
2078 Two Furthest Houses With Different Colors Greedy,Array Easy Weekly Contest 268
2079 Watering Plants Array Medium Weekly Contest 268
2080 Range Frequency Queries Design,Segment Tree,Array,Hash Table,Binary Search Medium Weekly Contest 268
2081 Sum of k-Mirror Numbers Math,Enumeration Hard Weekly Contest 268
2082 The Number of Rich Customers Database Easy ๐Ÿ”’
2083 Substrings That Begin and End With the Same Letter Hash Table,Math,String,Counting,Prefix Sum Medium ๐Ÿ”’
2084 Drop Type 1 Orders for Customers With Type 0 Orders Database Medium ๐Ÿ”’
2085 Count Common Words With One Occurrence Array,Hash Table,String,Counting Easy Biweekly Contest 66
2086 Minimum Number of Buckets Required to Collect Rainwater from Houses Greedy,String,Dynamic Programming Medium Biweekly Contest 66
2087 Minimum Cost Homecoming of a Robot in a Grid Greedy,Array,Matrix Medium Biweekly Contest 66
2088 Count Fertile Pyramids in a Land Array,Dynamic Programming,Matrix Hard Biweekly Contest 66
2089 Find Target Indices After Sorting Array Array,Binary Search,Sorting Easy Weekly Contest 269
2090 K Radius Subarray Averages Array,Sliding Window Medium Weekly Contest 269
2091 Removing Minimum and Maximum From Array Greedy,Array Medium Weekly Contest 269
2092 Find All People With Secret Depth-First Search,Breadth-First Search,Union Find,Graph,Sorting Hard Weekly Contest 269
2093 Minimum Cost to Reach City With Discounts Graph,Shortest Path Medium ๐Ÿ”’
2094 Finding 3-Digit Even Numbers Array,Hash Table,Enumeration,Sorting Easy Weekly Contest 270
2095 Delete the Middle Node of a Linked List Linked List,Two Pointers Medium Weekly Contest 270
2096 Step-By-Step Directions From a Binary Tree Node to Another Tree,Depth-First Search,String,Binary Tree Medium Weekly Contest 270
2097 Valid Arrangement of Pairs Depth-First Search,Graph,Eulerian Circuit Hard Weekly Contest 270
2098 Subsequence of Size K With the Largest Even Sum Greedy,Array,Sorting Medium ๐Ÿ”’
2099 Find Subsequence of Length K With the Largest Sum Array,Hash Table,Sorting,Heap (Priority Queue) Easy Biweekly Contest 67
2100 Find Good Days to Rob the Bank Array,Dynamic Programming,Prefix Sum Medium Biweekly Contest 67
2101 Detonate the Maximum Bombs Depth-First Search,Breadth-First Search,Graph,Geometry,Array,Math Medium Biweekly Contest 67
2102 Sequentially Ordinal Rank Tracker Design,Data Stream,Ordered Set,Heap (Priority Queue) Hard Biweekly Contest 67
2103 Rings and Rods Hash Table,String Easy Weekly Contest 271
2104 Sum of Subarray Ranges Stack,Array,Monotonic Stack Medium Weekly Contest 271
2105 Watering Plants II Array,Two Pointers,Simulation Medium Weekly Contest 271
2106 Maximum Fruits Harvested After at Most K Steps Array,Binary Search,Prefix Sum,Sliding Window Hard Weekly Contest 271
2107 Number of Unique Flavors After Sharing K Candies Array,Hash Table,Sliding Window Medium ๐Ÿ”’
2108 Find First Palindromic String in the Array Array,Two Pointers,String Easy Weekly Contest 272
2109 Adding Spaces to a String Array,String,Simulation Medium Weekly Contest 272
2110 Number of Smooth Descent Periods of a Stock Array,Math,Dynamic Programming Medium Weekly Contest 272
2111 Minimum Operations to Make the Array K-Increasing Array,Binary Search Hard Weekly Contest 272
2112 The Airport With the Most Traffic Database Medium ๐Ÿ”’
2113 Elements in Array After Removing and Replacing Elements Array Medium ๐Ÿ”’
2114 Maximum Number of Words Found in Sentences Array,String Easy Biweekly Contest 68
2115 Find All Possible Recipes from Given Supplies Graph,Topological Sort,Array,Hash Table,String Medium Biweekly Contest 68
2116 Check if a Parentheses String Can Be Valid Stack,Greedy,String Medium Biweekly Contest 68
2117 Abbreviating the Product of a Range Math Hard Biweekly Contest 68
2118 Build the Equation Database Hard ๐Ÿ”’
2119 A Number After a Double Reversal Math Easy Weekly Contest 273
2120 Execution of All Suffix Instructions Staying in a Grid String,Simulation Medium Weekly Contest 273
2121 Intervals Between Identical Elements Array,Hash Table,Prefix Sum Medium Weekly Contest 273
2122 Recover the Original Array Array,Hash Table,Enumeration,Sorting Hard Weekly Contest 273
2123 Minimum Operations to Remove Adjacent Ones in Matrix Graph,Array,Matrix Hard ๐Ÿ”’
2124 Check if All A's Appears Before All B's String Easy Weekly Contest 274
2125 Number of Laser Beams in a Bank Array,Math,String,Matrix Medium Weekly Contest 274
2126 Destroying Asteroids Greedy,Array,Sorting Medium Weekly Contest 274
2127 Maximum Employees to Be Invited to a Meeting Depth-First Search,Graph,Topological Sort Hard Weekly Contest 274
2128 Remove All Ones With Row and Column Flips Bit Manipulation,Array,Math,Matrix Medium ๐Ÿ”’
2129 Capitalize the Title String Easy Biweekly Contest 69
2130 Maximum Twin Sum of a Linked List Stack,Linked List,Two Pointers Medium Biweekly Contest 69
2131 Longest Palindrome by Concatenating Two Letter Words Greedy,Array,Hash Table,String,Counting Medium Biweekly Contest 69
2132 Stamping the Grid Greedy,Array,Matrix,Prefix Sum Hard Biweekly Contest 69
2133 Check if Every Row and Column Contains All Numbers Array,Hash Table,Matrix Easy Weekly Contest 275
2134 Minimum Swaps to Group All 1's Together II Array,Sliding Window Medium Weekly Contest 275
2135 Count Words Obtained After Adding a Letter Bit Manipulation,Array,Hash Table,String,Sorting Medium Weekly Contest 275
2136 Earliest Possible Day of Full Bloom Greedy,Array,Sorting Hard Weekly Contest 275
2137 Pour Water Between Buckets to Make Water Levels Equal Array,Binary Search Medium ๐Ÿ”’
2138 Divide a String Into Groups of Size k String,Simulation Easy Weekly Contest 276
2139 Minimum Moves to Reach Target Score Greedy,Math Medium Weekly Contest 276
2140 Solving Questions With Brainpower Array,Dynamic Programming Medium Weekly Contest 276
2141 Maximum Running Time of N Computers Greedy,Array,Binary Search,Sorting Hard Weekly Contest 276
2142 The Number of Passengers in Each Bus I Database Medium ๐Ÿ”’
2143 Choose Numbers From Two Arrays in Range Array,Dynamic Programming Hard ๐Ÿ”’
2144 Minimum Cost of Buying Candies With Discount Greedy,Array,Sorting Easy Biweekly Contest 70
2145 Count the Hidden Sequences Array,Prefix Sum Medium Biweekly Contest 70
2146 K Highest Ranked Items Within a Price Range Breadth-First Search,Array,Matrix,Sorting,Heap (Priority Queue) Medium Biweekly Contest 70
2147 Number of Ways to Divide a Long Corridor Math,String,Dynamic Programming Hard Biweekly Contest 70
2148 Count Elements With Strictly Smaller and Greater Elements Array,Sorting Easy Weekly Contest 277
2149 Rearrange Array Elements by Sign Array,Two Pointers,Simulation Medium Weekly Contest 277
2150 Find All Lonely Numbers in the Array Array,Hash Table,Counting Medium Weekly Contest 277
2151 Maximum Good People Based on Statements Bit Manipulation,Array,Backtracking,Enumeration Hard Weekly Contest 277
2152 Minimum Number of Lines to Cover Points Bit Manipulation,Geometry,Array,Hash Table,Math,Dynamic Programming,Backtracking,Bitmask Medium ๐Ÿ”’
2153 The Number of Passengers in Each Bus II Database Hard ๐Ÿ”’
2154 Keep Multiplying Found Values by Two Array,Hash Table,Sorting,Simulation Easy Weekly Contest 278
2155 All Divisions With the Highest Score of a Binary Array Array Medium Weekly Contest 278
2156 Find Substring With Given Hash Value String,Sliding Window,Hash Function,Rolling Hash Medium Weekly Contest 278
2157 Groups of Strings Bit Manipulation,Union Find,String Hard Weekly Contest 278
2158 Amount of New Area Painted Each Day Segment Tree,Array,Ordered Set Hard ๐Ÿ”’
2159 Order Two Columns Independently Database Medium ๐Ÿ”’
2160 Minimum Sum of Four Digit Number After Splitting Digits Greedy,Math,Sorting Easy Biweekly Contest 71
2161 Partition Array According to Given Pivot Array,Two Pointers,Simulation Medium Biweekly Contest 71
2162 Minimum Cost to Set Cooking Time Math,Enumeration Medium Biweekly Contest 71
2163 Minimum Difference in Sums After Removal of Elements Array,Dynamic Programming,Heap (Priority Queue) Hard Biweekly Contest 71
2164 Sort Even and Odd Indices Independently Array,Sorting Easy Weekly Contest 279
2165 Smallest Value of the Rearranged Number Math,Sorting Medium Weekly Contest 279
2166 Design Bitset Design,Array,Hash Table Medium Weekly Contest 279
2167 Minimum Time to Remove All Cars Containing Illegal Goods String,Dynamic Programming Hard Weekly Contest 279
2168 Unique Substrings With Equal Digit Frequency Hash Table,String,Counting,Hash Function,Rolling Hash Medium ๐Ÿ”’
2169 Count Operations to Obtain Zero Math,Simulation Easy Weekly Contest 280
2170 Minimum Operations to Make the Array Alternating Greedy,Array,Hash Table,Counting Medium Weekly Contest 280
2171 Removing Minimum Number of Magic Beans Array,Prefix Sum,Sorting Medium Weekly Contest 280
2172 Maximum AND Sum of Array Bit Manipulation,Array,Dynamic Programming,Bitmask Hard Weekly Contest 280
2173 Longest Winning Streak Database Hard ๐Ÿ”’
2174 Remove All Ones With Row and Column Flips II Bit Manipulation,Breadth-First Search,Array,Matrix Medium ๐Ÿ”’
2175 The Change in Global Rankings Database Medium ๐Ÿ”’
2176 Count Equal and Divisible Pairs in an Array Array Easy Biweekly Contest 72
2177 Find Three Consecutive Integers That Sum to a Given Number Math,Simulation Medium Biweekly Contest 72
2178 Maximum Split of Positive Even Integers Greedy,Math Medium Biweekly Contest 72
2179 Count Good Triplets in an Array Binary Indexed Tree,Segment Tree,Array,Binary Search,Divide and Conquer,Ordered Set,Merge Sort Hard Biweekly Contest 72
2180 Count Integers With Even Digit Sum Math,Simulation Easy Weekly Contest 281
2181 Merge Nodes in Between Zeros Linked List,Simulation Medium Weekly Contest 281
2182 Construct String With Repeat Limit Greedy,String,Counting,Heap (Priority Queue) Medium Weekly Contest 281
2183 Count Array Pairs Divisible by K Array,Math,Number Theory Hard Weekly Contest 281
2184 Number of Ways to Build Sturdy Brick Wall Bit Manipulation,Array,Dynamic Programming,Bitmask Medium ๐Ÿ”’
2185 Counting Words With a Given Prefix Array,String Easy Weekly Contest 282
2186 Minimum Number of Steps to Make Two Strings Anagram II Hash Table,String,Counting Medium Weekly Contest 282
2187 Minimum Time to Complete Trips Array,Binary Search Medium Weekly Contest 282
2188 Minimum Time to Finish the Race Array,Dynamic Programming Hard Weekly Contest 282
2189 Number of Ways to Build House of Cards Math,Dynamic Programming Medium ๐Ÿ”’
2190 Most Frequent Number Following Key In an Array Array,Hash Table,Counting Easy Biweekly Contest 73
2191 Sort the Jumbled Numbers Array,Sorting Medium Biweekly Contest 73
2192 All Ancestors of a Node in a Directed Acyclic Graph Depth-First Search,Breadth-First Search,Graph,Topological Sort Medium Biweekly Contest 73
2193 Minimum Number of Moves to Make Palindrome Greedy,Binary Indexed Tree,Two Pointers,String Hard Biweekly Contest 73
2194 Cells in a Range on an Excel Sheet String Easy Weekly Contest 283
2195 Append K Integers With Minimal Sum Greedy,Array,Math,Sorting Medium Weekly Contest 283
2196 Create Binary Tree From Descriptions Tree,Depth-First Search,Breadth-First Search,Array,Hash Table,Binary Tree Medium Weekly Contest 283
2197 Replace Non-Coprime Numbers in Array Stack,Array,Math,Number Theory Hard Weekly Contest 283
2198 Number of Single Divisor Triplets Math Medium ๐Ÿ”’
2199 Finding the Topic of Each Post Database Hard ๐Ÿ”’
2200 Find All K-Distant Indices in an Array Array Easy Weekly Contest 284
2201 Count Artifacts That Can Be Extracted Array,Hash Table,Simulation Medium Weekly Contest 284
2202 Maximize the Topmost Element After K Moves Greedy,Array Medium Weekly Contest 284
2203 Minimum Weighted Subgraph With the Required Paths Graph,Shortest Path Hard Weekly Contest 284
2204 Distance to a Cycle in Undirected Graph Depth-First Search,Breadth-First Search,Union Find,Graph Hard ๐Ÿ”’
2205 The Number of Users That Are Eligible for Discount Database Easy ๐Ÿ”’
2206 Divide Array Into Equal Pairs Bit Manipulation,Array,Hash Table,Counting Easy Biweekly Contest 74
2207 Maximize Number of Subsequences in a String Greedy,String,Prefix Sum Medium Biweekly Contest 74
2208 Minimum Operations to Halve Array Sum Greedy,Array,Heap (Priority Queue) Medium Biweekly Contest 74
2209 Minimum White Tiles After Covering With Carpets String,Dynamic Programming,Prefix Sum Hard Biweekly Contest 74
2210 Count Hills and Valleys in an Array Array Easy Weekly Contest 285
2211 Count Collisions on a Road Stack,String Medium Weekly Contest 285
2212 Maximum Points in an Archery Competition Bit Manipulation,Recursion,Array,Enumeration Medium Weekly Contest 285
2213 Longest Substring of One Repeating Character Segment Tree,Array,String,Ordered Set Hard Weekly Contest 285
2214 Minimum Health to Beat Game Greedy,Array,Prefix Sum Medium ๐Ÿ”’
2215 Find the Difference of Two Arrays Array,Hash Table Easy Weekly Contest 286
2216 Minimum Deletions to Make Array Beautiful Stack,Greedy,Array Medium Weekly Contest 286
2217 Find Palindrome With Fixed Length Array,Math Medium Weekly Contest 286
2218 Maximum Value of K Coins From Piles Array,Dynamic Programming,Prefix Sum Hard Weekly Contest 286
2219 Maximum Sum Score of Array Array,Prefix Sum Medium ๐Ÿ”’
2220 Minimum Bit Flips to Convert Number Bit Manipulation Easy Biweekly Contest 75
2221 Find Triangular Sum of an Array Array,Math,Combinatorics,Simulation Medium Biweekly Contest 75
2222 Number of Ways to Select Buildings String,Dynamic Programming,Prefix Sum Medium Biweekly Contest 75
2223 Sum of Scores of Built Strings String,Binary Search,String Matching,Suffix Array,Hash Function,Rolling Hash Hard Biweekly Contest 75
2224 Minimum Number of Operations to Convert Time Greedy,String Easy Weekly Contest 287
2225 Find Players With Zero or One Losses Array,Hash Table,Counting,Sorting Medium Weekly Contest 287
2226 Maximum Candies Allocated to K Children Array,Binary Search Medium Weekly Contest 287
2227 Encrypt and Decrypt Strings Design,Trie,Array,Hash Table,String Hard Weekly Contest 287
2228 Users With Two Purchases Within Seven Days Database Medium ๐Ÿ”’
2229 Check if an Array Is Consecutive Array Easy ๐Ÿ”’
2230 The Users That Are Eligible for Discount Database Easy ๐Ÿ”’
2231 Largest Number After Digit Swaps by Parity Sorting,Heap (Priority Queue) Easy Weekly Contest 288
2232 Minimize Result by Adding Parentheses to Expression String,Enumeration Medium Weekly Contest 288
2233 Maximum Product After K Increments Greedy,Array,Heap (Priority Queue) Medium Weekly Contest 288
2234 Maximum Total Beauty of the Gardens Greedy,Array,Two Pointers,Binary Search,Sorting Hard Weekly Contest 288
2235 Add Two Integers Math Easy
2236 Root Equals Sum of Children Tree,Binary Tree Easy
2237 Count Positions on Street With Required Brightness Array,Prefix Sum Medium ๐Ÿ”’
2238 Number of Times a Driver Was a Passenger Database Medium ๐Ÿ”’
2239 Find Closest Number to Zero Array Easy Biweekly Contest 76
2240 Number of Ways to Buy Pens and Pencils Math,Enumeration Medium Biweekly Contest 76
2241 Design an ATM Machine Greedy,Design,Array Medium Biweekly Contest 76
2242 Maximum Score of a Node Sequence Graph,Array,Enumeration,Sorting Hard Biweekly Contest 76
2243 Calculate Digit Sum of a String String,Simulation Easy Weekly Contest 289
2244 Minimum Rounds to Complete All Tasks Greedy,Array,Hash Table,Counting Medium Weekly Contest 289
2245 Maximum Trailing Zeros in a Cornered Path Array,Matrix,Prefix Sum Medium Weekly Contest 289
2246 Longest Path With Different Adjacent Characters Tree,Depth-First Search,Graph,Topological Sort,Array,String Hard Weekly Contest 289
2247 Maximum Cost of Trip With K Highways Bit Manipulation,Graph,Dynamic Programming,Bitmask Hard ๐Ÿ”’
2248 Intersection of Multiple Arrays Array,Hash Table,Counting Easy Weekly Contest 290
2249 Count Lattice Points Inside a Circle Geometry,Array,Hash Table,Math,Enumeration Medium Weekly Contest 290
2250 Count Number of Rectangles Containing Each Point Binary Indexed Tree,Array,Binary Search,Sorting Medium Weekly Contest 290
2251 Number of Flowers in Full Bloom Array,Hash Table,Binary Search,Ordered Set,Prefix Sum,Sorting Hard Weekly Contest 290
2252 Dynamic Pivoting of a Table Database Hard ๐Ÿ”’
2253 Dynamic Unpivoting of a Table Database Hard ๐Ÿ”’
2254 Design Video Sharing Platform Stack,Design,Hash Table,Ordered Set Hard ๐Ÿ”’
2255 Count Prefixes of a Given String Array,String Easy Biweekly Contest 77
2256 Minimum Average Difference Array,Prefix Sum Medium Biweekly Contest 77
2257 Count Unguarded Cells in the Grid Array,Matrix,Simulation Medium Biweekly Contest 77
2258 Escape the Spreading Fire Breadth-First Search,Array,Binary Search,Matrix Hard Biweekly Contest 77
2259 Remove Digit From Number to Maximize Result Greedy,String,Enumeration Easy Weekly Contest 291
2260 Minimum Consecutive Cards to Pick Up Array,Hash Table,Sliding Window Medium Weekly Contest 291
2261 K Divisible Elements Subarrays Trie,Array,Hash Table,Enumeration,Hash Function,Rolling Hash Medium Weekly Contest 291
2262 Total Appeal of A String Hash Table,String,Dynamic Programming Hard Weekly Contest 291
2263 Make Array Non-decreasing or Non-increasing Greedy,Dynamic Programming Hard ๐Ÿ”’
2264 Largest 3-Same-Digit Number in String String Easy Weekly Contest 292
2265 Count Nodes Equal to Average of Subtree Tree,Depth-First Search,Binary Tree Medium Weekly Contest 292
2266 Count Number of Texts Hash Table,Math,String,Dynamic Programming Medium Weekly Contest 292
2267 Check if There Is a Valid Parentheses String Path Array,Dynamic Programming,Matrix Hard Weekly Contest 292
2268 Minimum Number of Keypresses Greedy,Array,String,Counting,Sorting Medium ๐Ÿ”’
2269 Find the K-Beauty of a Number Math,String,Sliding Window Easy Biweekly Contest 78
2270 Number of Ways to Split Array Medium Biweekly Contest 78
2271 Maximum White Tiles Covered by a Carpet Greedy,Array,Binary Search,Prefix Sum,Sorting Medium Biweekly Contest 78
2272 Substring With Largest Variance Array,Dynamic Programming Hard Biweekly Contest 78
2273 Find Resultant Array After Removing Anagrams Array,Hash Table,String,Sorting Easy Weekly Contest 293
2274 Maximum Consecutive Floors Without Special Floors Array,Sorting Medium Weekly Contest 293
2275 Largest Combination With Bitwise AND Greater Than Zero Bit Manipulation,Array,Hash Table,Counting Medium Weekly Contest 293
2276 Count Integers in Intervals Design,Segment Tree,Ordered Set Hard Weekly Contest 293
2277 Closest Node to Path in Tree Tree,Depth-First Search,Breadth-First Search,Array Hard ๐Ÿ”’
2278 Percentage of Letter in String String Easy Weekly Contest 294
2279 Maximum Bags With Full Capacity of Rocks Greedy,Array,Sorting Medium Weekly Contest 294
2280 Minimum Lines to Represent a Line Chart Geometry,Array,Math,Number Theory,Sorting Medium Weekly Contest 294
2281 Sum of Total Strength of Wizards Stack,Array,Prefix Sum,Monotonic Stack Hard Weekly Contest 294
2282 Number of People That Can Be Seen in a Grid Stack,Array,Matrix,Monotonic Stack Medium ๐Ÿ”’
2283 Check if Number Has Equal Digit Count and Digit Value Hash Table,String,Counting Easy Biweekly Contest 79
2284 Sender With Largest Word Count Array,Hash Table,String,Counting Medium Biweekly Contest 79
2285 Maximum Total Importance of Roads Greedy,Graph,Sorting,Heap (Priority Queue) Medium Biweekly Contest 79
2286 Booking Concert Tickets in Groups Design,Binary Indexed Tree,Segment Tree,Binary Search Hard Biweekly Contest 79
2287 Rearrange Characters to Make Target String Hash Table,String,Counting Easy Weekly Contest 295
2288 Apply Discount to Prices String Medium Weekly Contest 295
2289 Steps to Make Array Non-decreasing Stack,Array,Linked List,Monotonic Stack Medium Weekly Contest 295
2290 Minimum Obstacle Removal to Reach Corner Breadth-First Search,Graph,Array,Matrix,Shortest Path,Heap (Priority Queue) Hard Weekly Contest 295
2291 Maximum Profit From Trading Stocks Array,Dynamic Programming Medium ๐Ÿ”’
2292 Products With Three or More Orders in Two Consecutive Years Database Medium ๐Ÿ”’
2293 Min Max Game Array,Simulation Easy Weekly Contest 296
2294 Partition Array Such That Maximum Difference Is K Greedy,Array,Sorting Medium Weekly Contest 296
2295 Replace Elements in an Array Array,Hash Table,Simulation Medium Weekly Contest 296
2296 Design a Text Editor Stack,Design,Linked List,String,Doubly-Linked List,Simulation Hard Weekly Contest 296
2297 Jump Game VIII Stack,Graph,Array,Dynamic Programming,Shortest Path,Monotonic Stack Medium ๐Ÿ”’
2298 Tasks Count in the Weekend Database Medium ๐Ÿ”’
2299 Strong Password Checker II String Easy Biweekly Contest 80
2300 Successful Pairs of Spells and Potions Array,Two Pointers,Binary Search,Sorting Medium Biweekly Contest 80
2301 Match Substring After Replacement Array,Hash Table,String,String Matching Hard Biweekly Contest 80
2302 Count Subarrays With Score Less Than K Array,Binary Search,Prefix Sum,Sliding Window Hard Biweekly Contest 80
2303 Calculate Amount Paid in Taxes Array,Simulation Easy Weekly Contest 297
2304 Minimum Path Cost in a Grid Array,Dynamic Programming,Matrix Medium Weekly Contest 297
2305 Fair Distribution of Cookies Bit Manipulation,Array,Dynamic Programming,Backtracking,Bitmask Medium Weekly Contest 297
2306 Naming a Company Bit Manipulation,Array,Hash Table,String,Enumeration Hard Weekly Contest 297
2307 Check for Contradictions in Equations Depth-First Search,Union Find,Graph,Array Hard ๐Ÿ”’
2308 Arrange Table by Gender Database Medium ๐Ÿ”’
2309 Greatest English Letter in Upper and Lower Case Hash Table,String,Enumeration Easy Weekly Contest 298
2310 Sum of Numbers With Units Digit K Greedy,Math,Dynamic Programming,Enumeration Medium Weekly Contest 298
2311 Longest Binary Subsequence Less Than or Equal to K Greedy,Memoization,String,Dynamic Programming Medium Weekly Contest 298
2312 Selling Pieces of Wood Memoization,Array,Dynamic Programming Hard Weekly Contest 298
2313 Minimum Flips in Binary Tree to Get Result Tree,Depth-First Search,Dynamic Programming,Binary Tree Hard ๐Ÿ”’
2314 The First Day of the Maximum Recorded Degree in Each City Database Medium ๐Ÿ”’
2315 Count Asterisks String Easy Biweekly Contest 81
2316 Count Unreachable Pairs of Nodes in an Undirected Graph Depth-First Search,Breadth-First Search,Union Find,Graph Medium Biweekly Contest 81
2317 Maximum XOR After Operations Bit Manipulation,Array,Math Medium Biweekly Contest 81
2318 Number of Distinct Roll Sequences Memoization,Dynamic Programming Hard Biweekly Contest 81
2319 Check if Matrix Is X-Matrix Array,Matrix Easy Weekly Contest 299
2320 Count Number of Ways to Place Houses Dynamic Programming Medium Weekly Contest 299
2321 Maximum Score Of Spliced Array Array,Dynamic Programming Hard Weekly Contest 299
2322 Minimum Score After Removals on a Tree Bit Manipulation,Tree,Depth-First Search,Array Hard Weekly Contest 299
2323 Find Minimum Time to Finish All Jobs II Greedy,Array,Sorting Medium ๐Ÿ”’
2324 Product Sales Analysis IV Database Medium ๐Ÿ”’
2325 Decode the Message Hash Table,String Easy Weekly Contest 300
2326 Spiral Matrix IV Array,Linked List,Matrix,Simulation Medium Weekly Contest 300
2327 Number of People Aware of a Secret Queue,Dynamic Programming,Simulation Medium Weekly Contest 300
2328 Number of Increasing Paths in a Grid Depth-First Search,Breadth-First Search,Graph,Topological Sort,Memoization,Array,Dynamic Programming,Matrix Hard Weekly Contest 300
2329 Product Sales Analysis V Medium ๐Ÿ”’
2330 Valid Palindrome IV Medium ๐Ÿ”’
2331 Evaluate Boolean Binary Tree Easy Biweekly Contest 82
2332 The Latest Time to Catch a Bus Medium Biweekly Contest 82
2333 Minimum Sum of Squared Difference Medium Biweekly Contest 82
2334 Subarray With Elements Greater Than Varying Threshold Hard Biweekly Contest 82
2335 Minimum Amount of Time to Fill Cups Easy Weekly Contest 301
2336 Smallest Number in Infinite Set Medium Weekly Contest 301
2337 Move Pieces to Obtain a String Medium Weekly Contest 301
2338 Count the Number of Ideal Arrays Hard Weekly Contest 301

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