#20 Valid Parentheses

来源：互联网发布：windows 桌面路径编辑：程序博客网时间：2024/06/07 18:34

题目：

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 "(]" and "([)]" are not.

题解：

考察栈的基本使用，简单的入栈和出栈即可解决。刚看到了一种好玩的for循环格式，这里用一下。

public class Solution {    public boolean isValid(String s) {        Stack<Character> stackS = new Stack<Character>();        char[] arr = s.toCharArray();        for (char c : arr) {            if(stackS.isEmpty()){                stackS.push(c);                continue;            }            Character temp = stackS.pop();                        // 配对时c不入栈            if (temp == '[' && c == ']') {            } <span style="white-space:pre"></span>    else if (temp == '(' && c == ')') {<span style="white-space:pre"></span>    }<span style="white-space:pre"></span>    else if (temp == '{' && c == '}') {<span style="white-space:pre"></span>    }<span style="white-space:pre"></span>    <span style="white-space:pre"></span>    <span style="white-space:pre"></span>    // 不配对时c入<span style="white-space:pre"></span>    else {<span style="white-space:pre"></span>        stackS.push(temp);<span style="white-space:pre"></span>        stackS.push(c);<span style="white-space:pre"></span>    }        }        return stackS.isEmpty();    }}

0 0