乘风破浪:LeetCode真题_022_Generate Parentheses 一.前言 关于括号的题目,我们已经遇到过了验证正确性的题目,现在让我们生成合法的括号列表,怎么办呢?想来想去还是递归比较方便. 二.Generate Parentheses 2.1 问题 2.2 分析与解决     既然用递归就要构造模型,这里我们定义left和right分别代表剩余的左右括号的数目,如果出现了left>right,那么就会出现实际上的左括号小于右括号的结果,出现错误,如果剩余都小于零就结束,只有都…

乘风破浪:LeetCode真题_020_Valid Parentheses 一.前言 下面开始堆栈方面的问题了,堆栈的操作基本上有压栈,出栈,判断栈空等等,虽然很简单,但是非常有意义. 二.Valid Parentheses 2.1 问题 2.2 分析与解决     我们可以看到通过堆栈,先压进符号的左半部分,然后如果下次直接是该符号的右半部分,那就弹出左半部分,否则继续压入符号的左半部分,如果此时是其他符号的右半部分,那就是错误了.每一次当形成一个整体的时候都会被弹出去,这样就能直接判断了.…

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…

这是悦乐书的第147次更新,第149篇原创 01 看题和准备 今天介绍的是LeetCode算法题中Easy级别的第6题(顺位题号是20),给定一个只包含字符'(',')','{','}','['和']'的字符串,确定输入字符串是否有效.输入的字符串必须使用相同类型的括号关闭左括号,并且以正确的顺序关闭左括号.如果输入空串,返回true.例如: 输入: "()" 输出: true 输入: "()[]{}" 输出: true 输入: "([)]" 输…

[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…

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…

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 &…

# -*- 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…

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 &…