题解 | #有效括号序列#

import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param s string字符串 
     * @return bool布尔型
     */
    public boolean isValid (String s) {
        Stack<Character> stack = new Stack<Character>();
        for(int i =0;i<s.length();i++){
            char temp = s.charAt(i);
            switch(temp){
                case '(':
                case '[':
                case '{':
                    stack.push(temp);
                    break;
                case ')':
                    if(stack.isEmpty()||stack.peek()!='(')
                        return false;
                    stack.pop();
                    break;
                case ']':
                    if(stack.isEmpty()||stack.peek()!='[')
                        return false;
                    stack.pop();
                    break;
                case '}':
                    if(stack.isEmpty()||stack.peek()!='{')
                        return false;
                    stack.pop();
                    break;
            }
        }
        return stack.isEmpty()?true:false;
    }
}