floodfill算法系列一＞扫雷游戏

题目思路：

代码设计：

代码呈现：

class Solution {
    int m,n;
    int[] dx = {0,0,-1,1,-1,-1,1,1};
    int[] dy = {-1,1,0,0,-1,1,-1,1};

    public char[][] updateBoard(char[][] board, int[] click) {
        m = board.length;
        n = board[0].length;
       int x = click[0], y = click[1];
        
        //直接点到地雷
        if(board[x][y] == 'M'){
            board[x][y] = 'X';
            return board;
        }

        dfs(board,x,y);
        return board;    
    }

    private void dfs(char[][] board, int i, int j){
        //统计周围地雷的个数
        int count = 0;

        for(int k = 0; k < 8; k++){
            int x = i + dx[k];
            int y = j + dy[k];
            if(x >= 0 && x < m && y >= 0 && y < n && board[x][y] == 'M'){
                count++;
            }
        }
        //去遍历未挖出的空方块

        //周围没有地雷
        if(count == 0){
            board[i][j] = 'B';
            for(int k = 0; k < 8; k++){
                int x = i + dx[k];
                int y = j + dy[k];
                if(x >= 0 && x < m && y >= 0 && y < n && board[x][y] == 'E'){
                    dfs(board,x,y);
                }
            }
        }else {
            //有地雷：修改它周围地雷个数，并返回
            board[i][j] = (char)(count + '0');
            return;
        }

        
    }
}