https://leetcode-cn.com/problems/reverse-words-in-a-string/ TLE代码: class Solution { public: string reverseWords(string s) { stringstream ss(s); string buf; vector<string> ans; while(ss<<buf){ ans.push_back(buf); } for(vector<string>::ite

第七题,Reverse Integer.(https://leetcode.com/problems/reverse-integer/description/) 注意事项:翻转之后,数据有可能会超过INT_MAX或者INT_MIN,所以最后用一个大一点的类型保存. leetcode中的跑的最快的解决办法,8ms: class Solution { public: int reverse(int x) { ?:-; long val=x; //注意,此处用long来定义,避免溢出 ) val=-v

翻转二叉树的步骤: 1.翻转根节点的左子树(递归调用当前函数) 2.翻转根节点的右子树(递归调用当前函数) 3.交换根节点的左子节点与右子节点 class Solution{ public: void exchage(TreeNode *root){ TreeNode* node=root; if (node!=NULL){ TreeNode* temp=node->left; node ->left=node->right; node->right=temp; } } TreeN

上一篇:LeetCode子域名访问计数-Python3.7<五> 题目:https://leetcode-cn.com/problems/score-after-flipping-matrix/description/ 废话:这次真的比以往的要难做,初次看题目,懵逼!题目都没懂!!!换个日子,咦?可以做做喔! 有一个二维矩阵 A 其中每个元素的值为 0 或 1 . 移动:选择任一行或列,并转换该行或列中的每一个值:将所有 0 都更改为 1,将所有 1 都更改为 0. 在做出任意次数的移动后,将

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 good   example" 输出: "examp

基本思路 从元首节点之后每次取一个节点,并将节点接到元首节点前面 代码实现 /** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {} * }; */ class Solution { public: ListNode* reverseList(ListNode* head) { if(head

贪心算法: LeetCode翻转矩阵后的得分-Python3<六> LeetCode根据身高重建队列-Python3<七> LeetCode 任务调度器-Python3<八> 哈希表: LeetCode 键盘行-Python3.7<四> LeetCode子域名访问计数-Python3.7<五> 数组操作: LeetCode两数之和-Python<一> LeetCode链表相加-Python<二> LeetCode-数组操作

1. KMP 算法 谈到字符串问题,不得不提的就是 KMP 算法,它是用来解决字符串查找的问题,可以在一个字符串(S)中查找一个子串(W)出现的位置.KMP 算法把字符匹配的时间复杂度缩小到 O(m+n) ,而空间复杂度也只有O(m).因为“暴力搜索”的方法会反复回溯主串,导致效率低下,而KMP算法可以利用已经部分匹配这个有效信息,保持主串上的指针不回溯,通过修改子串的指针,让模式串尽量地移动到有效的位置. 具体算法细节请参考: 字符串匹配的KMP算法 从头到尾彻底理解KMP 如何更好的理解和掌

Write a function that takes a string as input and reverse only the vowels of a string. Example 1:Given s = "hello", return "holle". Example 2:Given s = "leetcode", return "leotcede". 这道题让我们翻转字符串中的元音字母,元音字母有五个a,e,i,o

Write a function that takes a string as input and returns the string reversed. Example: Given s = "hello", return "olleh". 这道题没什么难度,直接从两头往中间走,同时交换两边的字符即可,参见代码如下: 解法一: class Solution { public: string reverseString(string s) { , right =

You are playing the following Flip Game with your friend: Given a string that contains only these two characters: + and -, you and your friend take turns to flip twoconsecutive "++" into "--". The game ends when a person can no longer

Invert a binary tree. 4 / \ 2 7 / \ / \ 1 3 6 9 to 4 / \ 7 2 / \ / \ 9 6 3 1 Trivia: This problem was inspired by this original tweet by Max Howell: Google: 90% of our engineers use the software you wrote (Homebrew), but you can’t invert a binary tre

Given an input string, reverse the string word by word. A word is defined as a sequence of non-space characters.The input string does not contain leading or trailing spaces and the words are always separated by a single space.For example,Given s = "t

Given an input string, reverse the string word by word. For example, Given s = "the sky is blue", return "blue is sky the". Update (2015-02-12): For C programmers: Try to solve it in-place in O(1) space. click to show clarification. Cl

Given a linked list, reverse the nodes of a linked list k at a time and return its modified list. If the number of nodes is not a multiple of k then left-out nodes in the end should remain as it is. You may not alter the values in the nodes, only nod

Reverse digits of an integer. Example1: x = 123, return 321 Example2: x = -123, return -321 click to show spoilers. Have you thought about this? Here are some good questions to ask before coding. Bonus points for you if you have already thought throu

Given two integers n and k, find how many different arrays consist of numbers from 1 to n such that there are exactly k inverse pairs. We define an inverse pair as following: For ith and jth element in the array, if i < j and a[i] > a[j] then it's a

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 contest" Output: "s'teL ekat edoCteeL tsetnoc"

Given a string and an integer k, you need to reverse the first k characters for every 2k characters counting from the start of the string. If there are less than k characters left, reverse all of them. If there are less than 2k but greater than or eq

We have a two dimensional matrix A where each value is 0 or 1. A move consists of choosing any row or column, and toggling each value in that row or column: changing all 0s to 1s, and all 1s to 0s. After making any number of moves, every row of this