重新整理LeetCode面试题系列代码.

Author: yanglr

README.md

@@ -1,2 +1,13 @@
-# leetcode-python
-Python玩转LeetCode系列文章代码
+# Python玩转LeetCode
+Python 玩转 LeetCode 的学习之路
+
+- [Python 玩转 LeetCode 面试题](http://www.justdopython.com/category/#/Leetcode面试题)
+- [Leetcode 面试系列 第1天：Leetcode 89 - 格雷码](http://www.justdopython.com/2019/09/09/python-leetcode89-gary-code/)
+- [LeetCode 面试系列 第2天：No.136 - 只出现一次的数](http://www.justdopython.com/2019/09/13/python-leetcode136-single-number/)
+- [LeetCode 面试系列 第3天：No.67 - 二进制数求和](http://www.justdopython.com/2019/09/14/python-leetcode67-add-binary/)
+- [LeetCode 面试系列 第4天：No.202 - 快乐数](http://www.justdopython.com/2019/09/28/python-leetcode202-happy-number/)
+- [LeetCode 面试系列 第5天：No.204 - 统计质数](http://www.justdopython.com/2019/10/04/python-leetcode204-count-primes/)
+
+关注公众号：python技术，回复"python"一起学习交流
+
+![](http://favorites.ren/assets/images/python.jpg)

leetcode-067/leetcode67.py

@@ -0,0 +1,10 @@
+class Solution:
+    def addBinary(self, a: str, b: str) -> str:
+        num1 = int(a, 2)
+        num2 = int(b, 2)
+        sum0 = num1 + num2
+        return format(sum0, 'b')
+
+# 测试
+sol = Solution()
+print(sol.addBinary('11', '1101'))

leetcode-089/leetcode89.py

@@ -0,0 +1,12 @@
+from typing import List
+
+class Solution:
+    def grayCode(self, n: int) -> List[int]:
+        res = [] 
+        for i in range(1 << n): 
+            res.append((i >> 1) ^ i) 
+        return res
+        
+# Below is testing
+obj = Solution()
+print(obj.grayCode(2))

leetcode-136/leetcode136-method1.py

@@ -0,0 +1,17 @@
+from typing import List
+
+class Solution:
+    def singleNumber(self, nums: List[int]) -> int:
+        res = 0
+        d = dict()
+        for num in nums:
+            if num not in d:
+                d[num] = 1
+            else:
+                d[num] += 1
+        res = next(k for k, val in d.items() if val == 1)
+        return res
+
+#以下是测试
+sol = Solution()
+print(sol.singleNumber([6, 4, 6, 2, 4]))

leetcode-136/solution-method2.py

@@ -0,0 +1,12 @@
+from typing import List
+
+class Solution:
+    def singleNumber(self, nums: List[int]) -> int:
+        r = 0
+        for i in nums:
+            r ^= i
+        return r
+
+#以下是测试
+sol = Solution()
+print(sol.singleNumber([6, 4, 6, 2, 4]))

leetcode-202/leetcode202.py

@@ -0,0 +1,18 @@
+class Solution:
+    def isHappy(self, n: int) -> bool:
+        unhappy = set()
+        while n not in unhappy and n != 1:
+            unhappy.add(n)
+            n = self.GetSquareSum(n)
+        return n == 1    
+
+    def GetSquareSum(self, n: int) -> bool:
+        sum0 = 0
+        while n > 0:
+            r = n - int(n/10)*10
+            n = int(n/10)
+            sum0 += r * r
+        return sum0
+
+sol = Solution()
+print(sol.isHappy(19))