programmers_올바른 괄호_java

https://school.programmers.co.kr/learn/courses/30/lessons/12909

프로그래머스

import java.util.*;

class Solution {
    boolean solution(String s) {
        boolean answer = true;

        Stack<Character> stack = new Stack<>();
        int size = s.length();
        
        for(int i = 0; i<size; i++){
            if(s.charAt(i) == '('){
                stack.push('(');
            }else if(s.charAt(i) == ')'){
                if(!stack.isEmpty()){
                    stack.pop();
                }else{
                    answer = false;
                    break;
                }
            } 
        }
        
        if(!stack.isEmpty()){
            answer = false;
        }
        
        return answer;
    }
}