스택을 활용한 풀이
import java.util.*;
class Solution {
boolean solution(String s) {
boolean answer = true;
Stack<Character> stack = new Stack<>();
for (int i = 0; i < s.length(); i++) {
if(s.charAt(i)=='('){
stack.push('(');
} else {
if (stack.isEmpty()) {
return false;
}
Character pop = stack.pop();
}
}
if (!stack.isEmpty()) {
return false;
}
return answer;
}
}