让我们一起来玩扫雷游戏！
给你一个大小为 m x n 二维字符矩阵 board，表示扫雷游戏的盘面，其中：
-
M代表一个 未挖出的 地雷， -
E代表一个 未挖出的 空方块， -
B代表没有相邻（上，下，左，右，和所有4个对角线）地雷的 已挖出的 空白方块， -
数字（
1到8）表示有多少地雷与这块 已挖出的 方块相邻， -
X则表示一个 已挖出的 地雷。
给你一个整数数组 click ，其中 click = [clickr, clickc] 表示在所有 未挖出的 方块（M 或者 E）中的下一个点击位置（clickr 是行下标，clickc 是列下标）。
根据以下规则，返回相应位置被点击后对应的盘面：
-
如果一个地雷（
M）被挖出，游戏就结束了- 把它改为X。 -
如果一个 没有相邻地雷 的空方块（
E）被挖出，修改它为（B），并且所有和其相邻的 未挖出 方块都应该被递归地揭露。 -
如果一个 至少与一个地雷相邻 的空方块（
E）被挖出，修改它为数字（1到8），表示相邻地雷的数量。 -
如果在此次点击中，若无更多方块可被揭露，则返回盘面。
示例 1：
输入：board = [
["E","E","E","E","E"],
["E","E","M","E","E"],
["E","E","E","E","E"],
["E","E","E","E","E"]
],
click = [3,0]
输出：[
["B","1","E","1","B"],
["B","1","M","1","B"],
["B","1","1","1","B"],
["B","B","B","B","B"]
]
示例 2：
输入：board = [["B","1","E","1","B"],["B","1","M","1","B"],["B","1","1","1","B"],["B","B","B","B","B"]], click = [1,2] 输出：[["B","1","E","1","B"],["B","1","X","1","B"],["B","1","1","1","B"],["B","B","B","B","B"]]
提示：
-
m == board.length -
n == board[i].length -
1 <= m, n <= 50 -
board[i][j]为M、E、B或数字1到8中的一个 -
click.length == 2 -
0 <= click~r~ < m -
0 <= click~c~ < n -
board[click~r~][click~c~]为M或E