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) {// write code hereStack<Character> stack = new Stack<Character>();for(int i = 0; i < s.length(); i++){if(s.charAt(i) == '('){stack.push(')');}else if(s.charAt(i) == '['){stack.push(']');}else if(s.charAt(i) == '{'){stack.push('}');}else if(stack.isEmpty() || s.charAt(i) != stack.pop()){return false;}}return stack.isEmpty();}
}