摘要：
Reverse digits of an integer.Example1:x = 123, return 321Example2:x = -123, return -321click to show spoilers.Have you thought about this?Here are som... 阅读全文
摘要：
You are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single ... 阅读全文
摘要：
Given a strings, partitionssuch that every substring of the partition is a palindrome.Return all possible palindrome partitioning ofs.For example, givens="aab",Return [ ["aa","b"], ["a","a","b"] ]对于这类返回所有结果集合的问题，通常都是使用DFS，递归算法Soluton:class 阅读全文
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Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.For example,"A man, a plan, a canal: Panama"is a palindrome."race a car"isnota palindrome.Note:Have you consider that the string might be empty? This is a good question to 阅读全文
摘要：
Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum.For example:Given the below binary tree andsum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ / \ 7 2 5 1return[ [5,4,11,2]... 阅读全文
摘要：
Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum.For example:Given the below binary tree andsum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ ... 阅读全文
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Given an array where elements are sorted in ascending order, convert it to a height balanced BST.Solution：BinaryTree* sortedArrayToBST(int arr[], int start, int end) { if (start > end) return NULL; // same as (start+end)/2, avoids overflow. int mid = start + (end - start) / 2; BinaryTree *node =. 阅读全文
摘要：
Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST.Solution:/** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {} * }; *//** * Definition for binary tre... 阅读全文
摘要：
Given a binary tree, determine if it is height-balanced.For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never differ by more than 1.Solution:/** * Definition for binary tree * struct TreeNode { * int val; * Tree... 阅读全文
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Given a binary tree, find its maximum depth.The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.递归版本：class Solution {public: int maxDepth(TreeNode *root) { if(!root) return 0; // !root else return max(maxDepth(root->left... 阅读全文