올바른 괄호

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

import java.util.*;

class Solution {
    boolean solution(String s) {
        char[] charArray = s.toCharArray();
        
        ArrayDeque<Character> arr = new ArrayDeque<>();
        
        for(char c : charArray){
            if(c == '('){
                arr.add('(');
                continue;
            }
            
            if(arr.isEmpty())
                return false;
            
            arr.poll();
            
        }
        
        return arr.isEmpty();
    }
}