[BOJ] 11899 괄호 끼워넣기 (JAVA)

https://www.acmicpc.net/problem/11899

11899번: 괄호 끼워넣기

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {
	
    public static void main(String[] args) throws Exception {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        char[] input = br.readLine().toCharArray();
        int cnt = 0;
        int sum = 0;
        for (int i = 0; i < input.length; i++) {
            if (input[i] == '(') sum++;
            else {
                if (0 < sum) sum--;
                else cnt++;
            }
        }

        System.out.print(cnt + sum);

    }
	
}