https://school.programmers.co.kr/learn/courses/30/lessons/12909
class Solution {
boolean solution(String s) {
java.util.Stack<Character> stack = new java.util.Stack<Character>();
for (int i=0; i<s.length(); i++) {
if (stack.isEmpty() && s.charAt(i) == ')') return false;
if(s.charAt(i)==')') stack.pop();
else stack.push(s.charAt(i));
}
if (stack.isEmpty()) return true;
else return false;
}
}
java.util.Stack<>을 활용한다.