짝지어 제거하기 (자바)

package prog;

import java.util.Stack;

public class 짝지어_제거하기 {
    public static void main(String[] args) {
        Solution_짝지어_제거하기 s = new Solution_짝지어_제거하기();
        System.out.println(s.solution("baabaa"));
        System.out.println(s.solution("cdcd"));
    }
}

class Solution_짝지어_제거하기
{
    public int solution(String s)
    {
        int answer = -1;
        Stack<Character> stack = new Stack<>();
        for (char c : s.toCharArray()) {
            if(stack.isEmpty()){
                stack.add(c);
            }
            else{
                if(stack.peek()==c){
                    stack.pop();
                }
                else stack.add(c);
            }
        }
        if(stack.isEmpty()) return 1;
        else return 0;

    }
}