★ [백준][Java] 5525번 IOIOI (문자열, 누적합)

참고 : https://mizzo-dev.tistory.com/entry/baekjoon5525  

 

IOI를 단위로 하여 누적을 시키고..

이 값이 계속 누적되는지 혹은 누적이 끊겨서 0이 되는지 변화를 살피고

그것을 체크하여 res값을 계산함

 

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
 
 
public class Main {
        
    private static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    private static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
    
    
    public static void main(String[] args) throws IOException{
        int N = stoi(br.readLine());
        int M = stoi(br.readLine());
        
        char[] input = br.readLine().toCharArray();
        
        int res = 0;
        int accumNum = 0;
        for(int i=2; i<M; i++) {
            if(input[i]=='I' && input[i-1]=='O' && input[i-2]=='I') {
                accumNum++;
                i++;
            }
            else {
                accumNum=0;
            }
            
            if(accumNum >= N) {
                res++;
            }
        }
        System.out.println(res);
        
//        bw.write();
//        bw.flush();
//        bw.close();
    }
    
    private static int stoi(String input) {
        return Integer.parseInt(input);
    }
    
}