[BOJ] 5525 IOIOI (JAVA)

https://www.acmicpc.net/problem/5525

5525번: IOIOI

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));
        int N = Integer.parseInt(br.readLine()) * 2 + 1;
        int M = Integer.parseInt(br.readLine());
        char[] input = br.readLine().toCharArray();
        int cnt = 0;
        int result = 0;
        char pre = 'O';
        boolean flag = false;

        for (int i = 0; i < M; i++) {
            if (input[i] == 'I') {
                if (pre == 'O') {
                    if (N <= ++cnt) flag = true;
                    if (flag) result++;
                } else {
                    cnt = 1;
                    flag = false;
                }
            } else {
                if (pre == 'I') cnt++;
                else {
                    cnt = 0;
                    flag = false;
                }
            }
            pre = input[i];
        }

        System.out.print(result);

    }

}