Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. The brackets must close in the correct order, "()" and "()[]{}" are all valid but "(]" and "([)]"…

括号匹配问题,使用栈的特点,匹配则出栈,否则入栈,最后栈为空则全部匹配.代码如下: class Solution { public: bool isValid(string s) { stack<char> T; ;i < s.length();i ++) { ) { T.push(s[i]); } else T.pop(); } if(T.empty()) return true; else return false; } };…

1. 原题链接 https://leetcode.com/problems/valid-parentheses/description/ 2. 题目要求 给定一个字符串s,s只包含'(', ')', '{', '}', '[' 和 ']'. 合法:形如“()[]“.”{[()]}“ 不合法:形如“([)]”.“[[((” 判断所给字符串s是否合法. 3. 解题思路 对字符串s转换成字符数字进行遍历. 利用栈,遇到左半边字符:'('.'['.'{'时,将其对应的右半边字符进行入栈.遇到不是左半边字…

Given a string containing just the characters '(' and ')', find the length of the longest valid (well-formed) parentheses substring. For "(()", the longest valid parentheses substring is "()", which has length = 2. Another example is &…

[问题描写叙述] Given a string containing just the characters '(' and ')', find the length of the longest valid (well-formed) parentheses substring. For "(()", the longest valid parentheses substring is "()", which has length = 2. Another exa…

Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. An input string is valid if: Open brackets must be closed by the same type of brackets. Open brackets must be closed in the correct…

题目链接 https://leetcode.com/problems/valid-parentheses/?tab=Description   Problem: 括号匹配问题. 使用栈,先进后出!   参考代码1: package leetcode_50; import java.util.Stack; /*** * * @author pengfei_zheng * 括号匹配问题 */ public class Solution20 { public static boolean isVali…

有一定的难度.用堆栈记录下所有左符的位置,用变量记录下孤立右符的位置. int longestValidParentheses(const string& s) { stack<int>lefts;//将左符对应的位置保留 int last;//记录孤立的右符位置 ;//记录当前最长的有效长度 ; i < s.size(); i++) { if (s[i] == '(') lefts.push(i); else { if (lefts.empty()) { last = i; }…

[032-Longest Valid Parentheses(最长有效括号)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 Given a string containing just the characters '(' and ')', find the length of the longest valid (well-formed) parentheses substring. For "(()", the longest valid pare…

这星期听别人说在做LeetCode,让他分享一题来看看.试了感觉挺有意思,可以培养自己的思路,还能方便的查看优秀的解决方案.准备自己也开始. 解决方案通常有多种多样,我觉得把自己的解决思路记录下来,阶段性查看,一定能对自己有帮助. 这是我做的第一题,所以记录也从这题开始,之后尽力以简短的说明,描述出思路,方便以后能回顾到简介明了的记录. 20. Valid Parentheses Given a string containing just the characters '(', ')', '{…