翻转字符串中的单词 力扣题目链接(opens new window) 给定一个字符串,逐个翻转字符串中的每个单词. 示例 1: 输入: "the sky is blue" 输出: "blue is sky the" 示例 2: 输入: " hello world! " 输出: "world! hello" 解释: 输入字符串可以在前面或者后面包含多余的空格,但是反转后的字符不能包括. 示例 3: 输入: "a goo…

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 longest palindromic substring. Tags: String 容易想到的思路(可以解但会超时): class Solution { public: string longestPalin…

Leetcode:面试题 04.03. 特定深度节点链表 Leetcode:面试题 04.03. 特定深度节点链表 先贴一下自己写过一个模板,按层数遍历: https://www.cnblogs.com/cell-coder/p/12344619.html 里面有这类题的模板 这道题就是这种类型的变种,只需要按题目意思改一下就ok 贴一下我的通过代码: /** * Definition for a binary tree node. * struct TreeNode { * int val;…

3. Longest Substring Without Repeating Characters Given a string, find the length of the longest substring without repeating characters. Examples: Given . Given . Given . Note that the answer must be a substring, "pwke" is a subsequence and not…

题目链接:https://leetcode-cn.com/problems/delete-middle-node-lcci/ 实现一种算法,删除单向链表中间的某个节点(除了第一个和最后一个节点,不一定是中间节点),假定你只能访问该节点. 示例: 输入:单向链表a->b->c->d->e->f中的节点c结果:不返回任何数据,但该链表变为a->b->d->e->f 思路:意思就是删除这个节点,实际操作是把该节点的值用后面的值覆盖,删除后面的结点,因为单链表…

Additive number is a positive integer whose digits can form additive sequence. A valid additive sequence should contain at least three numbers. Except for the first two numbers, each subsequent number in the sequence must be the sum of the preceding…

Given an integer n, count the total number of digit 1 appearing in all non-negative integers less than or equal to n. For example: Given n = 13, Return 6, because digit 1 occurred in the following numbers: 1, 10, 11, 12, 13. Hint: Beware of overflow.…

Given an unsorted array of integers, find the length of the longest consecutive elements sequence. For example, Given [100, 4, 200, 1, 3, 2], The longest consecutive elements sequence is [1, 2, 3, 4]. Return its length: 4. Your algorithm should run i…

Design and implement a data structure for Least Frequently Used (LFU) cache. It should support the following operations: get and set. get(key) - Get the value (will always be positive) of the key if the key exists in the cache, otherwise return -1. s…

题意:将整数倒置,该题简单但是需要注意数据的范围,难得的好题. 如果出现1000000003或者-2000000003,倒置后的数超过int的范围,因此返回0,出现这种情况可以使用long long,也可以在在乘以10时进行判断. 注意:Leetcode是用linux环境的,所以他用的是g++4.78编译器,不是vc++编译器,为此在vc++编译器上我们用__int64,而g++编译器就是long long,这些是64位的int,很有用的东西,不做过相关的竞赛或者项目的人,大部分人都不知道C++…