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. 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…
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 &…
第一种方法,用栈实现,最容易想到,也比较容易实现,每次碰到‘)’时update max_len,由于要保存之前的‘(’的index,所以space complexity 是O(n) // 使用栈,时间复杂度 O(n),空间复杂度 O(n) class Solution { public: int longestValidParentheses(string s) { , last = -; stack<int> lefts; ; i < s.size(); ++i) { if (s[i]…
Longest Valid Parentheses 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…
(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…
题目大意:给出一个只包含字符'('和')'的字符串S,求最长有效括号序列的长度. 很有趣的题目,有助于我们对这种人类自身制定的规则的深入理解,可能我们大多数人都从没有真正理解过怎样一个括号序列是有效的,因此解题也无从说起.整道题目的难度在于我们对有效括号序列的理解和定义.下面给出我自己的定义:. 定义1:空括号序列是有效的. 定义2:对于一对左右括号,若左括号出现在右括号的左边,且左右括号之间(不包含两端)的括号序列是有效的,那么称该左括号到该右括号(包含)这一段序列是有效的.且称该左括号和右括…
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…
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)…
class Solution(object): def longestValidParentheses(self, s): """ :type s: str :rtype: int """ maxlen=0 stack=[] last=-1 for i in range(len(s)): if s[i] == '(': stack.append(i) else: if stack == []: last=i else: stack.pop() i…
一.题目说明 题目是32. Longest Valid Parentheses,求最大匹配的括号长度.题目的难度是Hard 二.我的做题方法 简单理解了一下,用栈就可以实现.实际上是我考虑简单了,经过5次提交终于正确了. 性能如下: Runtime: 8 ms, faster than 61.76% of C++ online submissions for Longest Valid Parentheses. Memory Usage: 9.8 MB, less than 10.71% of…
32. 最长有效括号 32. Longest Valid Parentheses 题目描述 给定一个只包含 '(' 和 ')' 的字符串,找出最长的包含有效括号的子串的长度. 每日一算法2019/6/3Day 31LeetCode32. Longest Valid Parentheses 示例 1: 输入: "(()" 输出: 2 解释: 最长有效括号子串为 "()" 示例 2: 输入: ")()())" 输出: 4 解释: 最长有效括号子串为…
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 long…
指数:[LeetCode] Leetcode 指标解释 (C++/Java/Python/Sql) Github: https://github.com/illuz/leetcode 032. Longest Valid Parentheses (Hard) 链接: 题目:https://oj.leetcode.com/problems/longest-valid-parentheses/ 代码(github):https://github.com/illuz/leetcode 题意: 问一个字…
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…
题目: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 i…
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…
[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 ')', 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 &…
Longest Valid Parentheses 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…
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…
# -*- coding: utf8 -*-'''__author__ = 'dabay.wang@gmail.com' 32: Longest Valid Parentheseshttps://oj.leetcode.com/problems/longest-valid-parentheses/ Given a string containing just the characters '(' and ')',find the length of the longest valid (well…
一天一道LeetCode系列 (一)题目 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.…
1. Valid Parentheses 题目链接 题目要求: 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 &q…
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] == '['…