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…

https://leetcode.com/problems/valid-parentheses/ 原题: Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. The brackets must close in the correct order, "()" and "()[]{}"…

题目 给定一个只包括 '(',')','{','}','[',']' 的字符串 s ,判断字符串是否有效. 有效字符串需满足: 左括号必须用相同类型的右括号闭合. 左括号必须以正确的顺序闭合. 示例 1: 输入:s = "()" 输出:true 思路 当出现右括号时,如'(','{','[' 必定需要对象的左括号,才能时是个闭合的字符串 代码 public bool IsValid(string s) { List<char> ayyayC = new List<ch…

前言   [LeetCode 题解]系列传送门:  http://www.cnblogs.com/double-win/category/573499.html   1.题目描述 Given an integer, convert it to a roman numeral. Input is guaranteed to be within the range from 1 to 3999. 2. 思路 给定一个数字,将其转换成罗马数制,输入域1~3999 使用贪心的方法,从高位向低位一次比较.…

前言   [LeetCode 题解]系列传送门:  http://www.cnblogs.com/double-win/category/573499.html   1.题目描述 Given a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999. 2. 思路 找到规则即可 罗马数字的表示: I~1 V~5 X~10 L~50 C~100 D~500…

前言   [LeetCode 题解]系列传送门:  http://www.cnblogs.com/double-win/category/573499.html   1.题目描述 Given an array with n objects colored red, white or blue, sort them so that objects of the same color are adjacent, with the colors in the order red, white and…

前言   [LeetCode 题解]系列传送门:  http://www.cnblogs.com/double-win/category/573499.html   1.题目描述 Find the contiguous subarray within an array (containing at least one number) which has the largest sum. For example, given the array [−2,1,−3,4,−1,2,1,−5,4], t…

前言   [LeetCode 题解]系列传送门:  http://www.cnblogs.com/double-win/category/573499.html   1.题目描述 There are N gas stations along a circular route, where the amount of gas at station i is gas[i]. You have a car with an unlimited gas tank and it costs cost[i]…

前言   [LeetCode 题解]系列传送门:  http://www.cnblogs.com/double-win/category/573499.html   1.题目描述 Given a non-negative number represented as an array of digits, plus one to the number. The digits are stored such that the most significant digit is at the head…

前言   [LeetCode 题解]系列传送门:  http://www.cnblogs.com/double-win/category/573499.html   1.题目描述 The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for b…