【LeetCode & Q20-Valid Parentheses-Easy】的更多相关文章

[leetcode] 20. Valid Parentheses (easy)

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…

[LeetCode] 036. Valid Sudoku (Easy) (C++)

指数:[LeetCode] Leetcode 解决问题的指数 (C++/Java/Python/Sql) Github: https://github.com/illuz/leetcode 036. Valid Sudoku (Easy) 链接: 题目:https://leetcode.com/problems/valid-sudoku/ 代码(github):https://github.com/illuz/leetcode 题意: 推断一个数独是否有效. 有效的数独不强求有解. 分析: 仅仅…

[LeetCode] Longest Valid Parentheses 最长有效括号

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 &…

[LeetCode] Longest Valid Parentheses 解题思路

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 &…

[Leetcode] longest valid parentheses 最长的有效括号

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")…

[LeetCode] Longest Valid Parentheses -- 挂动态规划羊头卖stack的狗肉

(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…

[LeetCode] 20. Valid Parentheses 验证括号

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…

[LeetCode] 20. Valid Parentheses 合法括号

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…

[LeetCode] Longest Valid Parentheses

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]…

[LeetCode] Longest Valid Parentheses 动态规划

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 &…