백준 9012번 괄호 (JAVA)

소스코드

import java.util.Scanner;
import java.util.Stack;
 
public class Main{
 
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        boolean flag = false;
        Stack<String> stack = new Stack<>();
        for(int i=0; i<n; i++) {
            String a = sc.next();
            String[] c = a.split("");
            stack.clear();
            
            for(int j=0; j<c.length; j++) {
                if(c[j].equals("(")){
                    stack.push(c[j]);    
                }else {
                    if(stack.size() == 0) {
                        flag = true;
                        break;
                    }
                    stack.pop();
                }
            }
            if(flag || stack.size() > 0) {
                System.out.println("NO");
            }else {
                System.out.println("YES");
            }
            flag = false;
            
        }
    }
}