프로그래머스 - 안전지대 (JAVA)

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class Solution {
    public int solution(int[][] board) {
       int answer = 0;
        int n = board.length;
        boolean[][] check = new boolean[n][n];

        for(int i = 0; i < board.length; i++){
            for(int j = 0; j < board[i].length; j++){
                if(board[i][j] == 1){
                    check[i][j] = true;
                    if(i>0) check[i-1][j] = true;
                    if(j>0) check[i][j-1] = true;
                    if(i<n-1) check[i+1][j] = true;
                    if(j<n-1) check[i][j+1] = true;
                    if(i>0 && j>0) check[i-1][j-1] = true;
                    if(i>0 && j<n-1) check[i-1][j+1] = true;
                    if(i<n-1 && j>0) check[i+1][j-1] = true;
                    if(i<n-1 && j<n-1) check[i+1][j+1] = true;
                }
            }
        }
        for(int i = 0;  i < check.length; i++){
            for(int j = 0; j < check[i].length; j++){
                if(!check[i][j]){
                    answer++;
                }
            }
        }

        return answer;
    }
}