[프로그래머스/Java] 안전지대

-Code

class Solution {
    public int solution(int[][] board) {
        int answer = (int) Math.pow(board.length, 2);
        int[] dy = {1, 1, 1, 0, 0, -1, -1, -1};
        int[] dx = {-1, 0, 1, -1, 1, -1, 0, 1};

        for (int i = 0; i < board.length; i++) {
            for (int j = 0; j < board[i].length; j++) {
                if (board[i][j] == 1) {
                    answer-= 1;
                    for (int k = 0; k < 8; k++) {
                        int y = i + dy[k], x = j + dx[k];
                        if (y < 0 || y > board.length - 1|| x < 0 || x > board.length - 1) {
                            continue;
                        }
                        if (board[y][x] == 0) {
                            board[y][x] = -1;
                            answer -= 1;
                        }
                    }
                }
            }
        }

        return answer;
    }
}