摘要： Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). For example, this binary tree is symmetric: But the fol 阅读全文

摘要： Given a binary tree Populate each next pointer to point to its next right node. If there is no next right node, the next pointer should be set to NULL 阅读全文

摘要： Given a binary tree, flatten it to a linked list in-place. For example,Given The flattened tree should look like: 阅读全文

摘要： Given a binary tree, return the inorder traversal of its nodes' values. For example:Given binary tree {1,#,2,3}, return [1,3,2]. 代码如下： 阅读全文

摘要： Given a binary tree, imagine yourself standing on the right side of it, return the values of the nodes you can see ordered from top to bottom. For exa 阅读全文

摘要： Find the contiguous subarray within an array (containing at least one number) which has the largest sum. For example, given the array [−2,1,−3,4,−1,2, 阅读全文

摘要： Given an array S of n integers, are there elements a, b, c in S such that a + b + c = 0? Find all unique triplets in the array which gives the sum of 阅读全文

摘要： Given an integer, convert it to a roman numeral. Input is guaranteed to be within the range from 1 to 3999. 代码如下： 阅读全文

摘要： Given n non-negative integers a1, a2, ..., an, where each represents a point at coordinate (i, ai). n vertical lines are drawn such that the two endpo 阅读全文

摘要： Given a string S, find the longest palindromic substring in S. You may assume that the maximum length of S is 1000, and there exists one unique longes 阅读全文