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文章目录1：Reverse Integer1：Reverse Integer题目描述：输入：红圈的范围输出：整数的翻转分析：考察，int类型整数的取值范围样例输入：1534236469，翻转后9*******5时，在乘以10得90多亿超出20多亿的int范围解决办法：在乘以10之前判断，超过了就返回0，break掉private static int reverse(int x) { int num = 0; int yu; while (x != 0) {

题目描述Given a string, find the first non-repeating character in it and return it’s index. If it doesn’t exist, return -1.Examples:s = “leetcode”return 0.s = “loveleetcode”,return 2.Note: You may ...

问题描述：Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).Note:Bonus points if you could solve it both recursively and iteratively.解题思路：递归的方法，每次递归的调用判断左子...

题目描述：Given a string, you need to reverse the order of characters in each word within a sentence while still preserving whitespace and initial word order.Example 1:Input: “Let’s take LeetCode contes...

题目描述：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.Note: A leaf is a node with no chi...

题目描述：Given a binary tree, return the level order traversal of its nodes’ values. (ie, from left to right, level by level).For example:Given binary tree [3,9,20,null,null,15,7], 3 / ...

Given a string s consists of upper/lower-case alphabets and empty space characters ’ ', return the length of last word in the string.If the last word does not exist, return 0.Note: A word is defined...

问题描述：Given preorder and inorder traversal of a tree, construct the binary tree.Note:You may assume that duplicates do not exist in the tree.For example, givenpreorder = [3,9,20,15,7]inorder = [9...

问题描述：Given a binary tree, return the bottom-up level order traversal of its nodes’ values. (ie, from left to right, level by level from leaf to root).For example:Given binary tree [3,9,20,null,null...