Grokking the Coding Interveiw By mhinzz

Overview:

Grokking the Coding Interview equivalent questions on Leetcode

• 1. Pattern: Sliding Window

  • Maximum Sum Subarray of Size K (easy)
    • https://leetcode.com/problems/maximum-subarray/
  • Smallest Subarray with a given sum (easy)
    • https://leetcode.com/problems/minimum-size-subarray-sum/
  • Longest Substring with K Distinct Characters (medium) *
    • https://leetcode.com/problems/longest-substring-with-at-most-k-distinct-characters/
  • Fruits into Baskets (medium)
    • https://leetcode.com/problems/fruit-into-baskets/
  • No-repeat Substring (hard)
    • https://leetcode.com/problems/longest-substring-without-repeating-characters/
  • Longest Substring with Same Letters after Replacement (hard)
    • https://leetcode.com/problems/longest-repeating-character-replacement/
  • Longest Subarray with Ones after Replacement (hard)
    • https://leetcode.com/problems/max-consecutive-ones-iii/
  • Problem Challenge 1 - Permutation in a String (hard)
    • https://leetcode.com/problems/permutation-in-string/
  • Problem Challenge 2 - String Anagrams (hard)
    • https://leetcode.com/problems/find-all-anagrams-in-a-string/
  • Problem Challenge 3 - Smallest Window containing Substring (hard)
    • https://leetcode.com/problems/minimum-window-substring/
  • Problem Challenge 4 - Words Concatenation (hard)
    • https://leetcode.com/problems/substring-with-concatenation-of-all-words/

• 2. Pattern: Two Pointers

  • Pair with Target Sum (easy)
    • https://leetcode.com/problems/two-sum/
    • https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/
  • Remove Duplicates (easy)
    • https://leetcode.com/problems/remove-duplicates-from-sorted-array/
  • Squaring a Sorted Array (easy)
    • https://leetcode.com/problems/squares-of-a-sorted-array/
  • Triplet Sum to Zero (medium)
    • https://leetcode.com/problems/3sum/
  • Triplet Sum Close to Target (medium)
    • https://leetcode.com/problems/3sum-closest/
  • Triplets with Smaller Sum (medium)
    • https://leetcode.com/problems/3sum-smaller/
  • Subarrays with Product Less than a Target (medium)
    • https://leetcode.com/problems/subarray-product-less-than-k/
  • Problem Challenge 1 - Quadruple Sum to Target (medium)
    • https://leetcode.com/problems/4sum/
  • Problem Challenge 2 - Comparing Strings containing Backspaces (medium)
    • https://leetcode.com/problems/backspace-string-compare/
  • Problem Challenge 3 - Minimum Window Sort (medium)
    • https://leetcode.com/problems/shortest-unsorted-continuous-subarray/

• 3. Pattern: Fast & Slow pointers

  • LinkedList Cycle (easy)
    • https://leetcode.com/problems/linked-list-cycle/
  • Middle of the LinkedList (easy)
    • https://leetcode.com/problems/middle-of-the-linked-list/
  • Start of LinkedList Cycle (medium)
    • https://leetcode.com/problems/linked-list-cycle-ii/
  • Happy Number (medium)
    • https://leetcode.com/problems/happy-number/
  • Problem Challenge 1 - Palindrome LinkedList (medium)
    • https://leetcode.com/problems/palindrome-linked-list/
  • Problem Challenge 2 - Rearrange a LinkedList (medium)
    • https://leetcode.com/problems/reorder-list/
  • Problem Challenge 3 - Cycle in a Circular Array (hard)
    • https://leetcode.com/problems/circular-array-loop/

• 4. Pattern: Merge Intervals

  • Merge Intervals (medium)
    • https://leetcode.com/problems/merge-intervals/
  • Insert Interval (medium)
    • https://leetcode.com/problems/insert-interval/
  • Intervals Intersection (medium)
    • https://leetcode.com/problems/interval-list-intersections/
  • Conflicting Appointments (medium) *
    • https://leetcode.com/problems/meeting-rooms/
  • Problem Challenge 1 - Minimum Meeting Rooms (hard) *
    • https://leetcode.com/problems/meeting-rooms-ii/
  • Problem Challenge 2 - Maximum CPU Load (hard)
    • https://leetcode.com/problems/maximum-profit-in-job-scheduling/
  • Problem Challenge 3 - Employee Free Time (hard) *
    • https://leetcode.com/problems/employee-free-time/

• 5. Pattern: Cyclic Sort

  • Cyclic Sort (easy)
    • https://leetcode.com/problems/missing-number/discuss/859510/C%2B%2B-O(N)-O(1)-using-Cyclic-Sort
  • Find the Missing Number (easy)
    • https://leetcode.com/problems/missing-number/
  • Find all Missing Numbers (easy)
    • https://leetcode.com/problems/find-all-numbers-disappeared-in-an-array/
  • Find the Duplicate Number (easy)
    • https://leetcode.com/problems/find-the-duplicate-number/
  • Find all Duplicate Numbers (easy)
    • https://leetcode.com/problems/find-all-duplicates-in-an-array/
  • Problem Challenge 1 - Find the Corrupt Pair (easy)
    • https://leetcode.com/problems/set-mismatch/
  • Problem Challenge 2 - Find the Smallest Missing Positive Number (medium)
    • https://leetcode.com/problems/first-missing-positive/
  • Problem Challenge 3 - Find the First K Missing Positive Numbers (hard)
    • https://leetcode.com/problems/kth-missing-positive-number/

• 6. Pattern: In-place Reversal of a LinkedList

  • Reverse a LinkedList (easy)
    • https://leetcode.com/problems/reverse-linked-list/
  • Reverse a Sub-list (medium)
    • https://leetcode.com/problems/reverse-linked-list-ii/
  • Reverse every K-element Sub-list (medium)
    • https://leetcode.com/problems/reverse-nodes-in-k-group/
  • Problem Challenge 1 - Reverse alternating K-element Sub-list (medium)
    • Next question is the same, but alternate each subgroup
  • Problem Challenge 2 - Rotate a LinkedList (medium)
    • https://leetcode.com/problems/rotate-list/

• 7. Pattern: Tree Breadth First Search

  • Binary Tree Level Order Traversal (easy)
    • https://leetcode.com/problems/binary-tree-level-order-traversal/
  • Reverse Level Order Traversal (easy)
    • https://leetcode.com/problems/binary-tree-level-order-traversal-ii/
  • Zigzag Traversal (medium)
    • https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/
  • Level Averages in a Binary Tree (easy)
    • https://leetcode.com/problems/average-of-levels-in-binary-tree/
  • Minimum Depth of a Binary Tree (easy)
    • https://leetcode.com/problems/minimum-depth-of-binary-tree/
  • Level Order Successor (easy) *
    • https://leetcode.com/problems/inorder-successor-in-bst/
  • Connect Level Order Siblings (medium)
    • https://leetcode.com/problems/populating-next-right-pointers-in-each-node/
  • Problem Challenge 1 - Connect All Level Order Siblings (medium) *
    • Next question is the same, but connect end nodes to the next level instead of null
  • Problem Challenge 2 - Right View of a Binary Tree (easy)
    • https://leetcode.com/problems/binary-tree-right-side-view/

• 8. Pattern: Tree Depth First Search

  • Binary Tree Path Sum (easy)
    • https://leetcode.com/problems/path-sum/
  • All Paths for a Sum (medium)
    • https://leetcode.com/problems/path-sum-ii/
  • Sum of Path Numbers (medium)
    • https://leetcode.com/problems/sum-root-to-leaf-numbers/
  • Path With Given Sequence (medium) *
    • https://leetcode.com/problems/check-if-a-string-is-a-valid-sequence-from-root-to-leaves-path-in-a-binary-tree/
  • Count Paths for a Sum (medium)
    • https://leetcode.com/problems/path-sum-iii/
  • Problem Challenge 1 - Tree Diameter (medium)
    • https://leetcode.com/problems/diameter-of-binary-tree/
  • Problem Challenge 2 - Path with Maximum Sum (hard)
    • https://leetcode.com/problems/binary-tree-maximum-path-sum/

• 9. Pattern: Two Heaps

  • Find the Median of a Number Stream (medium)
    • https://leetcode.com/problems/find-median-from-data-stream/
  • Sliding Window Median (hard)
    • https://leetcode.com/problems/sliding-window-median/
  • Maximize Capital (hard) *
    • https://leetcode.com/problems/ipo/
  • Problem Challenge 1 - Next Interval (hard)
    • https://leetcode.com/problems/find-right-interval/

• 10. Pattern: Subsets

  • Subsets (easy)
    • https://leetcode.com/problems/subsets/
  • Subsets With Duplicates (easy)
    • https://leetcode.com/problems/subsets-ii/
  • Permutations (medium)
    • https://leetcode.com/problems/permutations/
  • String Permutations by changing case (medium)
    • https://leetcode.com/problems/letter-case-permutation/
  • Balanced Parentheses (hard)
    • https://leetcode.com/problems/generate-parentheses/
  • Unique Generalized Abbreviations (hard) *
    • https://leetcode.com/problems/generalized-abbreviation/
  • Problem Challenge 1 - Evaluate Expression (hard)
    • https://leetcode.com/problems/different-ways-to-add-parentheses/
  • Problem Challenge 2 - Structurally Unique Binary Search Trees (hard)
    • https://leetcode.com/problems/unique-binary-search-trees-ii/
  • Problem Challenge 3 - Count of Structurally Unique Binary Search Trees (hard)
    • https://leetcode.com/problems/unique-binary-search-trees/

• 11. Pattern: Modified Binary Search

  • Order-agnostic Binary Search (easy)
    • https://leetcode.com/problems/binary-search/
  • Ceiling of a Number (medium)
    • Did not find. Problem is find index of smallest element greater or equal to input value
  • Next Letter (medium)
    • https://leetcode.com/problems/find-smallest-letter-greater-than-target/
  • Number Range (medium)
    • https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array/
  • Search in a Sorted Infinite Array (medium) *
    • https://leetcode.com/problems/search-in-a-sorted-array-of-unknown-size/
  • Minimum Difference Element (medium)
    • https://leetcode.com/problems/find-k-closest-elements/
  • Bitonic Array Maximum (easy)
    • https://leetcode.com/problems/peak-index-in-a-mountain-array/
  • Problem Challenge 1 - Search Bitonic Array (medium)
    • https://leetcode.com/problems/find-in-mountain-array/
  • Problem Challenge 2 - Search in Rotated Array (medium)
    • https://leetcode.com/problems/search-in-rotated-sorted-array/
  • Problem Challenge 3 - Rotation Count (medium)
    • https://leetcode.com/problems/find-minimum-in-rotated-sorted-array/

• 12. Pattern: Bitwise XOR

  • Single Number (easy)
    • https://leetcode.com/problems/single-number/
  • Two Single Numbers (medium)
    • https://leetcode.com/problems/single-number-iii/
  • Complement of Base 10 Number (medium)
    • https://leetcode.com/problems/complement-of-base-10-integer/
  • Problem Challenge 1 - Flipping an Image
    • https://leetcode.com/problems/flipping-an-image/

• 13. Pattern: Top 'K' elements

• Top 'K' Numbers (easy)
  • Same as second question, but the first Grokking question wants the top K instead of the bottom K
• Kth Smallest Number (easy)
  • https://leetcode.com/problems/kth-largest-element-in-an-array
• 'K' Closest Points to the Origin (easy)
  • https://leetcode.com/problems/k-closest-points-to-origin/
• Connect Ropes (easy)
  • https://leetcode.com/problems/minimum-cost-to-connect-sticks/
• Top 'K' Frequent Numbers (medium)
  • https://leetcode.com/problems/top-k-frequent-elements/
• Frequency Sort (medium)
  • https://leetcode.com/problems/sort-characters-by-frequency/
• Kth Largest Number in a Stream (medium)
  • https://leetcode.com/problems/kth-largest-element-in-a-stream/
• 'K' Closest Numbers (medium)
  • https://leetcode.com/problems/find-k-closest-elements/
• Maximum Distinct Elements (medium)
  • https://leetcode.com/problems/least-number-of-unique-integers-after-k-removals/
  • https://www.geeksforgeeks.org/maximum-distinct-elements-removing-k-elements/
• Sum of Elements (medium)
  • https://www.geeksforgeeks.org/sum-elements-k1th-k2th-smallest-elements/
• Rearrange String (hard)
  • https://leetcode.com/problems/reorganize-string/
• Problem Challenge 1 - Rearrange String K Distance Apart (hard)
  • https://leetcode.com/problems/rearrange-string-k-distance-apart/
• Problem Challenge 2 - Scheduling Tasks (hard)
  • https://leetcode.com/problems/task-scheduler/
• Problem Challenge 3 - Frequency Stack (hard)
  • https://leetcode.com/problems/maximum-frequency-stack/

• 14. Pattern: K-way merge

  • Merge K Sorted Lists (medium)
    • https://leetcode.com/problems/merge-k-sorted-lists/
  • Kth Smallest Number in M Sorted Lists (Medium) *
    • Same as previous, but return the Kth smallest number
  • Kth Smallest Number in a Sorted Matrix (Hard)
    • https://leetcode.com/problems/kth-smallest-element-in-a-sorted-matrix/
  • Smallest Number Range (Hard)
    • https://leetcode.com/problems/smallest-range-covering-elements-from-k-lists/
  • Problem Challenge 1 - K Pairs with Largest Sums (Hard) *
    • https://leetcode.com/problems/find-k-pairs-with-smallest-sums/

• 15. Pattern: 0/1 Knapsack

  • 0/1 Knapsack (medium)
    • https://www.educative.io/courses/grokking-dynamic-programming-patterns-for-coding-interviews/RM1BDv71V60
  • Equal Subset Sum Partition (medium)
    • https://www.educative.io/courses/grokking-dynamic-programming-patterns-for-coding-interviews/3jEPRo5PDvx
    • https://leetcode.com/problems/partition-equal-subset-sum/
  • Subset Sum (medium)
    • https://www.educative.io/courses/grokking-dynamic-programming-patterns-for-coding-interviews/3j64vRY6JnR
    • https://leetcode.com/problems/subarray-sum-equals-k/
  • Minimum Subset Sum Difference (hard) *
    • https://leetcode.com/problems/last-stone-weight-ii/
    • https://leetcode.com/problems/partition-array-into-two-arrays-to-minimize-sum-difference/
  • Problem Challenge 1 - Count of Subset Sum (hard) *
    • https://leetcode.com/problems/combination-sum-ii/
    • https://leetcode.com/problems/combination-sum-iv/
  • Problem Challenge 2 - Target Sum (hard)
    • https://leetcode.com/problems/target-sum/
  • BONUS : Not in grokking, but still useful *
    • https://leetcode.com/problems/ones-and-zeroes/

• 16. Pattern: Topological Sort

  • Topological Sort (medium)
    • First problem is identical to the following three
  • Tasks Scheduling (medium)
    • https://leetcode.com/problems/course-schedule/
  • Tasks Scheduling Order (medium)
    • https://leetcode.com/problems/course-schedule-ii/
  • All Tasks Scheduling Orders (hard)
    • Same as above, but return all instead of any
  • Alien Dictionary (hard) *
    • https://leetcode.com/problems/alien-dictionary/
  • Problem Challenge 1 - Reconstructing a Sequence (hard) *
    • https://leetcode.com/problems/sequence-reconstruction/
  • Problem Challenge 2 - Minimum Height Trees (hard)
    • https://leetcode.com/problems/minimum-height-trees/

• 17. Misc

  • Kth Smallest Number (hard) *
    • https://leetcode.com/problems/kth-largest-element-in-an-array/

• 18. Extra (Multi-Threaded)

  • https://leetcode.com/problems/same-tree/
  • https://leetcode.com/problems/invert-binary-tree/
  • https://leetcode.com/problems/binary-search-tree-iterator/

Credit to aditya109 for help compiling this list.