241209 봄버맨

public static void main(String[] args) throws IOException {
	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	StringTokenizer st = new StringTokenizer(br.readLine());

	int rows = Integer.parseInt(st.nextToken());
	int cols = Integer.parseInt(st.nextToken());
	int time = Integer.parseInt(st.nextToken());

	char[][] map = readInitialMap(br, rows, cols);

	if (time <= 1) {
		printMap(map);
		return;
	}

	char[][] resultMap = simulateBombExplosion(map, rows, cols, time);
	printMap(resultMap);
}

private static char[][] readInitialMap(BufferedReader br, int rows, int cols) throws IOException {
	char[][] map = new char[rows][cols];
	for (int i = 0; i < rows; i++) {
		map[i] = br.readLine().toCharArray();
	}
	return map;
}

private static char[][] simulateBombExplosion(char[][] map, int rows, int cols, int time) {
	if (time % 2 == 0) {
		return fillWithBombs(rows, cols);
	} else {
		boolean firstExplosion = (time % 4 == 3);
		return firstExplosion ? performExplosion(map, rows, cols)
				: performExplosion(performExplosion(map, rows, cols), rows, cols);
	}
}

private static char[][] fillWithBombs(int rows, int cols) {
	char[][] filledMap = new char[rows][cols];
	for (int i = 0; i < rows; i++) {
		for (int j = 0; j < cols; j++) {
			filledMap[i][j] = 'O';
		}
	}
	return filledMap;
}

private static char[][] performExplosion(char[][] map, int rows, int cols) {
	char[][] explodedMap = new char[rows][cols];
	int[] dr = { 1, 0, -1, 0 };
	int[] dc = { 0, 1, 0, -1 };

	for (int i = 0; i < rows; i++) {
		for (int j = 0; j < cols; j++) {
			explodedMap[i][j] = 'O';
		}
	}

	markMap(map, rows, cols, explodedMap, dr, dc);

	return explodedMap;
}

private static void markMap(char[][] map, int rows, int cols, char[][] explodedMap, int[] dr, int[] dc) {
	for (int i = 0; i < rows; i++) {
		for (int j = 0; j < cols; j++) {
			if (map[i][j] == 'O') {
				explodedMap[i][j] = '.';
				for (int d = 0; d < 4; d++) {
					int ni = i + dr[d];
					int nj = j + dc[d];
					if (isValidPosition(ni, nj, rows, cols)) {
						explodedMap[ni][nj] = '.';
					}
				}
			}
		}
	}
}

private static boolean isValidPosition(int row, int col, int rows, int cols) {
	return row >= 0 && col >= 0 && row < rows && col < cols;
}

private static void printMap(char[][] map) {
	StringBuilder sb = new StringBuilder();
	for (char[] row : map) {
		sb.append(row).append("\n");
	}
	System.out.print(sb);
}

출처:https://www.acmicpc.net/problem/16918