leetcode529. 扫雷游戏

1、题目

https://leetcode-cn.com/problems/minesweeper/

2、题意

题解1：dfs
当前这个格子’E’若为’B’说明周围8个格子没有雷,继续搜索它其它八个格子为’E’的格子 (若为数字则说明有雷 则不用扩散)

class Solution {
public:
    vector<vector<char>> updateBoard(vector<vector<char>>& board, vector<int>& click) {
        if(board[click[0]][click[1]]=='M')
        {
            board[click[0]][click[1]] = 'X';
            return board;
        }
        else
        {
            dfs(board,click[0],click[1]);
        }
        return board;
    }
    int dx[8] = {-1,-1,-1,0,0,1,1,1},dy[8] = {-1,0,1,-1,1,-1,0,1};
    void dfs(vector<vector<char>>& board,int x,int y)
    {
        int m = board.size(),n = board[0].size();
        if(board[x][y]=='E')
        {
            int cnt = 0;
            for(int i=0;i<8;i++)
            {
                int x1 = x+dx[i],y1 = y+dy[i];
                if(x1>=0&&x1<m&&y1>=0&&y1<n)
                {
                    if(board[x1][y1]=='M')
                        cnt++;
                }
            }
            if(cnt>0)
                board[x][y] = '0'+cnt;
            else
            {
                board[x][y] = 'B';
                for(int i=0;i<8;i++)
                {
                    int x1 = x+dx[i],y1 = y+dy[i];
                    if(x1>=0&&x1<m&&y1>=0&&y1<n&&board[x1][y1]=='E')
                        dfs(board,x1,y1);
                }
            }
        }
    }
};