Given a string containing just the characters '(' and ')', find the length of the longest valid (well-formed) parentheses substring. Example 1: Input: "(()" Output: 2 Explanation: The longest valid parentheses substring is "()" Example…
Given a string containing just the characters '(' and ')', find the length of the longest valid (well-formed) parentheses substring. Example 1: Input: "(()" Output: 2 Explanation: The longest valid parentheses substring is "()" Example…
参考: 1. https://leetcode.com/problems/longest-valid-parentheses/solution/ 2. https://blog.csdn.net/accepthjp/article/details/52439449 知道是用动态规划解决,但是写不出状态转移方程... 最后查看官方solution,理解了状态转移方程的由来! class Solution { public: int longestValidParentheses(string s)…
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 &…
题目描述: 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 exampl…
给一个只包含 '(' 和 ')' 的字符串,找出最长的有效(正确关闭)括号子串的长度.对于 "(()",最长有效括号子串为 "()" ,它的长度是 2.另一个例子 ")()())",最长有效括号子串为 "()()",它的长度是 4.详见:https://leetcode.com/problems/longest-valid-parentheses/description/ Java实现: start变量来记录合法括号串的起始位…
题目链接: https://leetcode.com/problems/longest-valid-parentheses/?tab=Description   Problem :已知字符串s,求出其中最长的括号合法组合长度   设置两个指针,一个表示左括号open的个数 ,另一个表示右括号close的个数.     方法:两次遍历操作,第一次从前往后遍历,第二次从后向前遍历. 因此时间复杂度为O(n) 1.从左向右扫描,当遇到左括号时,open++,当遇到右括号时,close++       …
原题链接 题意: 寻找配对的(),并且返回最长可成功配对长度. 思路 配对的()必须是连续的,比如()((),最长长度为2:()(),最长长度为4. 解法一 dp: 利用dp记录以s[i]为终点时,最长可配对长度. 仅当遍历到s[i]==')'的时候记录. dp[i]=dp[i-1]+2 加上当前组其他对的长度 dp[i]+=dp[i-dp[i]] 加上邻近的上一组的总长度 class Solution { public: int longestValidParentheses(string s…
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] == '['…