529 Minesweeper 扫雷游戏

详见：https://leetcode.com/problems/minesweeper/description/

C++：

class Solution {
public:
    vector<vector<char>> updateBoard(vector<vector<char>>& board, vector<int>& click)
    {
        if (board.empty() || board[0].empty())
        {
            return {};
        }
        int m = board.size(), n = board[0].size(), row = click[0], col = click[1], cnt = 0;
        if (board[row][col] == 'M')
        {
            board[row][col] = 'X';
        }
        else
        {
            for (int i = -1; i < 2; ++i)
            {
                for (int j = -1; j < 2; ++j)
                {
                    int x = row + i, y = col + j;
                    if (x < 0 || x >= m || y < 0 || y >= n)
                    {
                        continue;
                    }
                    if (board[x][y] == 'M')
                    {
                        ++cnt;
                    }
                }
            }
            if (cnt > 0)
            {
                board[row][col] = cnt + '0';
            }
            else
            {
                board[row][col] = 'B';
                for (int i = -1; i < 2; ++i)
                {
                    for (int j = -1; j < 2; ++j)
                    {
                        int x = row + i, y = col + j;
                        if (x < 0 || x >= m || y < 0 || y >= n)
                        {
                            continue;
                        }
                        if (board[x][y] == 'E')
                        {
                            vector<int> nextPos{x, y};
                            updateBoard(board, nextPos);
                        }
                    }
                }
            }
        }
        return board;
    }
};

参考：http://www.cnblogs.com/grandyang/p/6536694.html