[BOJ] 1343 폴리오미노 (JAVA)

https://www.acmicpc.net/problem/1343

1343번: 폴리오미노

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 len = input.length;
        for (int i = 0; i < len; i++) {
            if (input[i] == 'X') {
                if (i + 3 < len && input[i + 1] == 'X' && input[i + 2] == 'X' && input[i + 3] == 'X') {
                    input[i] = input[i + 1] = input[i + 2] = input[i + 3] = 'A';
                    i += 3;
                } else if (i + 1 < len && input[i + 1] == 'X') {
                    input[i] = input[i + 1] = 'B';
                    i++;
                } else {
                    System.out.println(-1);
                    return;
                }
            }
        }

        StringBuilder sb = new StringBuilder();
        for (char c : input) {
            sb.append(c);
        }
        System.out.print(sb);

    }
	
}