我这一题写了好多测试都过了，但是提交就过10%,感觉自己陷入了思路死角，求各位大佬指点 import java.util.Scanner; import java.util.Stack; /** * @Author: * @Date: Created in 18:51 2018/4/9 */ public class Test03 { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int n = sc.nextInt(); sc.nextLine(); for (int j = 0; j < n; j++) { String str = sc.nextLine(); Stack<Character> stack = new Stack<>(); stack.push(str.charAt(0)); for (int i = 1; i < str.length(); i++) { if (str.charAt(i) == '(') { stack.push(str.charAt(i)); } else if (str.charAt(i)==')'){ if (!stack.isEmpty()) { if (stack.peek().equals('(')) stack.pop(); else stack.push(str.charAt(i)); } else stack.push(str.charAt(i)); } } if (stack.size() == 2) { char c = stack.pop(); if (c=='(' && stack.pop().equals(')')) System.out.println("Yes"); else System.out.println("No"); } else System.out.println("No"); } } }