判断括号是否合法 1.用stack存入左括号“([{”,遇到相应的右括号“)]}”就退栈 2.判断stack是否为空,可以判断是否合法 class Solution { public: bool isValid(string s) { stack<char> sc; char in[] ="([{"; char out[] =")]}"; ; i < s.size(); ++i){ ; j < ; ++j){ if(in[j] == s[i]…
20. Valid Parentheses 错误解法: "[])"就会报错,没考虑到出现')'.']'.'}'时,stack为空的情况,这种情况也无法匹配 class Solution { public: bool isValid(string s) { if(s.empty()) return false; stack<char> st; st.push(s[]); ;i < s.size();i++){ if(s[i] == '(' || s[i] == '['…
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…
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…
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…
Valid Parentheses  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 "(]"…
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; } };…
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 "([)]"…
转载:https://leetcode.windliang.cc/leetCode-20-Valid%20Parentheses.html 描述 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…
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 "([)]"…
题目描述: 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 "([)…
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 "([)]"…
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…
题目 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 "([)]&q…
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…
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…
利用栈的操作,遇到"(","[","{"即进栈,遇到")","]","}"判断是否与栈顶匹配,若不匹配则false. class Solution { public: bool isValid(string s) { stack<char> c; ;i<s.size();i++){ if(!c.empty()){ if(s[i]=='('||s[i]=='{'||s[i…
描述: 给定一些列括号,判断其有效性,即左括号有对应的有括号,括号种类只为小,中,大括号. 解决: 用栈. bool isValid(string s) { stack<char> st; for (auto i : s) { if (i == '(' || i == '[' || i == '{') { st.push(i); continue; } else { if (st.empty()) return false; char c = st.top(); if (i == ')' &a…
原题链接 匹配括号 思路: 用栈,遍历过程中,匹配的成对出栈:结束后,栈空则对,栈非空则错. Runtime: 4 ms, faster than 99.94% of Java class Solution { public boolean isValid(String s) { Stack<Character> sta = new Stack<Character>(); for (int i = 0; i < s.length(); i++) { char temp = s…
# -*- coding: utf8 -*-'''__author__ = 'dabay.wang@gmail.com' 20: Valid Parentheseshttps://oj.leetcode.com/problems/valid-parentheses/ Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is vali…
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 '(', ')', '{…
20. Valid Parentheses 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 "(]&quo…
我现在在做一个叫<leetbook>的免费开源书项目,力求提供最易懂的中文思路,目前把解题思路都同步更新到gitbook上了,需要的同学可以去看看 书的地址:https://hk029.gitbooks.io/leetbook/ 20. Valid Parentheses 问题 Given a string containing just the characters ‘(‘, ‘)’, ‘{‘, ‘}’, ‘[’ and ‘]’, determine if the input string…
1.题目 20. Valid Parentheses——Easy  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 brac…
一.题目说明 这个题目是20. Valid Parentheses,简单来说就是括号匹配.在学数据结构的时候,用栈可以解决.题目难度是Medium. 二.我的解答 栈涉及的内容不多,push.pop.top,. 我总共提交了3次: 第1次:Runtime Error,错误原因在于pop的时候,未判断栈是否为空. 第2次:Wrong Answer,这个是"眼大"疏忽导致的,我写的时候只考虑了()[]未考虑{}. 第3次:终于正确了,性能还可以: Runtime: 0 ms, faster…
20.Valid Parentheses 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…
(Version 1.3) 这题在LeetCode上的标签比较有欺骗性,虽然标签写着有DP,但是实际上根本不需要使用动态规划,相反的,使用动态规划反而会在LeetCode OJ上面超时.这题正确的做法应该和Largest Rectangle in Histogram那几个使用stack来记录并寻找左边界的题比较类似,因为在仔细分析问题并上手尝试解决时,会发现问题的关键在于怎么判定一个valid parentheses子串的起始位置,或者说当遇到一个')'时,怎么知道要加到哪里去. 第一次做的时候…
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 &…
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 &…
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")…