<p>Let&#39;s play the minesweeper game (<a href="https://en.wikipedia.org/wiki/Minesweeper_(video_game)" target="_blank">Wikipedia</a>, <a href="http://minesweeperonline.com" target="_blank">online game</a>)!</p>

<p>You are given an <code>m x n</code> char matrix <code>board</code> representing the game board where:</p>

<ul>
	<li><code>&#39;M&#39;</code> represents an unrevealed mine,</li>
	<li><code>&#39;E&#39;</code> represents an unrevealed empty square,</li>
	<li><code>&#39;B&#39;</code> represents a revealed blank square that has no adjacent mines (i.e., above, below, left, right, and all 4 diagonals),</li>
	<li>digit (<code>&#39;1&#39;</code> to <code>&#39;8&#39;</code>) represents how many mines are adjacent to this revealed square, and</li>
	<li><code>&#39;X&#39;</code> represents a revealed mine.</li>
</ul>

<p>You are also given an integer array <code>click</code> where <code>click = [click<sub>r</sub>, click<sub>c</sub>]</code> represents the next click position among all the unrevealed squares (<code>&#39;M&#39;</code> or <code>&#39;E&#39;</code>).</p>

<p>Return <em>the board after revealing this position according to the following rules</em>:</p>

<ol>
	<li>If a mine <code>&#39;M&#39;</code> is revealed, then the game is over. You should change it to <code>&#39;X&#39;</code>.</li>
	<li>If an empty square <code>&#39;E&#39;</code> with no adjacent mines is revealed, then change it to a revealed blank <code>&#39;B&#39;</code> and all of its adjacent unrevealed squares should be revealed recursively.</li>
	<li>If an empty square <code>&#39;E&#39;</code> with at least one adjacent mine is revealed, then change it to a digit (<code>&#39;1&#39;</code> to <code>&#39;8&#39;</code>) representing the number of adjacent mines.</li>
	<li>Return the board when no more squares will be revealed.</li>
</ol>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img src="https://assets.leetcode.com/uploads/2023/08/09/untitled.jpeg" style="width: 500px; max-width: 400px; height: 269px;" />
<pre>
<strong>Input:</strong> board = [[&quot;E&quot;,&quot;E&quot;,&quot;E&quot;,&quot;E&quot;,&quot;E&quot;],[&quot;E&quot;,&quot;E&quot;,&quot;M&quot;,&quot;E&quot;,&quot;E&quot;],[&quot;E&quot;,&quot;E&quot;,&quot;E&quot;,&quot;E&quot;,&quot;E&quot;],[&quot;E&quot;,&quot;E&quot;,&quot;E&quot;,&quot;E&quot;,&quot;E&quot;]], click = [3,0]
<strong>Output:</strong> [[&quot;B&quot;,&quot;1&quot;,&quot;E&quot;,&quot;1&quot;,&quot;B&quot;],[&quot;B&quot;,&quot;1&quot;,&quot;M&quot;,&quot;1&quot;,&quot;B&quot;],[&quot;B&quot;,&quot;1&quot;,&quot;1&quot;,&quot;1&quot;,&quot;B&quot;],[&quot;B&quot;,&quot;B&quot;,&quot;B&quot;,&quot;B&quot;,&quot;B&quot;]]
</pre>

<p><strong class="example">Example 2:</strong></p>
<img src="https://assets.leetcode.com/uploads/2023/08/09/untitled-2.jpeg" style="width: 489px; max-width: 400px; height: 269px;" />
<pre>
<strong>Input:</strong> board = [[&quot;B&quot;,&quot;1&quot;,&quot;E&quot;,&quot;1&quot;,&quot;B&quot;],[&quot;B&quot;,&quot;1&quot;,&quot;M&quot;,&quot;1&quot;,&quot;B&quot;],[&quot;B&quot;,&quot;1&quot;,&quot;1&quot;,&quot;1&quot;,&quot;B&quot;],[&quot;B&quot;,&quot;B&quot;,&quot;B&quot;,&quot;B&quot;,&quot;B&quot;]], click = [1,2]
<strong>Output:</strong> [[&quot;B&quot;,&quot;1&quot;,&quot;E&quot;,&quot;1&quot;,&quot;B&quot;],[&quot;B&quot;,&quot;1&quot;,&quot;X&quot;,&quot;1&quot;,&quot;B&quot;],[&quot;B&quot;,&quot;1&quot;,&quot;1&quot;,&quot;1&quot;,&quot;B&quot;],[&quot;B&quot;,&quot;B&quot;,&quot;B&quot;,&quot;B&quot;,&quot;B&quot;]]
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>m == board.length</code></li>
	<li><code>n == board[i].length</code></li>
	<li><code>1 &lt;= m, n &lt;= 50</code></li>
	<li><code>board[i][j]</code> is either <code>&#39;M&#39;</code>, <code>&#39;E&#39;</code>, <code>&#39;B&#39;</code>, or a digit from <code>&#39;1&#39;</code> to <code>&#39;8&#39;</code>.</li>
	<li><code>click.length == 2</code></li>
	<li><code>0 &lt;= click<sub>r</sub> &lt; m</code></li>
	<li><code>0 &lt;= click<sub>c</sub> &lt; n</code></li>
	<li><code>board[click<sub>r</sub>][click<sub>c</sub>]</code> is either <code>&#39;M&#39;</code> or <code>&#39;E&#39;</code>.</li>
</ul>

class Solution {
public:
    int countNeighbouringMines(vector<vector<char>>& board, int r, int c){
        int count = 0;
        for(int i=r-1; i<=r+1; i++){
            for(int j=c-1; j<=c+1; j++){
                if (i>=0 && i<board.size() && j>=0 && j<board[0].size() && board[i][j] == 'M'){
                    count++;
                }
            }
        }
        return count;
    }
    void dfs(vector<vector<char>>& board, int r, int c){
        if(r<0 || r>=board.size() || c<0 || c>=board[0].size()) return;
        if(board[r][c] != 'E') return;

        int neighbourMines = countNeighbouringMines(board, r, c);

        if(neighbourMines == 0){
            board[r][c] = 'B';
            vector<vector<int>> dirs = {{1,0},{0,1},{0,-1},{-1,0},{1,1},{1,-1},{-1,-1},{-1,1}};
            for(const auto& dir:dirs){
                dfs(board, r+dir[0], c+dir[1]);
            }
        }
        else{
            board[r][c] = '0' + neighbourMines;
        }
        // [["B","B","B","B","B","B","1","E"],
        //  ["B","1","1","1","B","B","1","M"],
        //  ["1","E","M","1","B","B","1","1"],
        //  ["M","E","1","1","B","B","B","B"],
        //  ["1","1","B","B","B","B","B","B"],
        //  ["B","B","B","B","B","B","B","B"],
        //  ["B","1","2","2","1","B","B","B"],
        //  ["B","1","M","M","1","B","B","B"]]

//         0 0
// 1 0
// 2 0
// 1 1
// 0 0
// 0 1
// 1 1
// 0 2
// 1 2
// 0 3
// 1 3
// 0 4
// 1 4
// 2 4
// 3 4
// 4 4
// 5 4
// 6 4
// 5 5
// 6 5
// 7 5
// 7 6
// 7 7
// 7 6
// 6 7
// 7 7
// 6 6
// 7 6
// 6 7
// 6 5
// 5 6
// 6 6
// 5 7
// 6 7
// 5 6
// 4 7
// 5 7
// 4 6
// 5 6
// 4 7
// 4 5
// 5 5
// 4 6
// 4 4
// 3 5
// 4 5
// 3 6
// 4 6
// 3 7
// 4 7
// 3 6
// 2 7
// 3 5
// 2 6
// 3 4
// 2 5
// 3 5
// 2 6
// 2 4
// 1 5
// 2 5
// 1 6
// 1 4
// 0 5
// 1 5
// 0 6
// 0 4
// 3 6
// 3 7
// 5 5
// 4 6
// 5 7
// 7 5
// 6 6
// 7 4
// 6 5
// 6 6
// 6 4
// 5 5
// 5 6
// 5 4
// 4 5
// 5 3
// 6 3
// 5 4
// 5 2
// 6 2
// 5 3
// 5 1
// 6 1
// 5 2
// 5 0
// 6 0
// 7 0
// 7 1
// 6 0
// 6 1
// 5 0
// 5 1
// 4 0
// 4 1
// 4 2
// 5 2
// 4 3
// 5 3
// 4 4
// 4 2
// 3 3
// 4 1
// 3 2
// 4 3
// 4 4
// 4 5
// 4 3
// 3 4
// 3 5
// 3 3
// 2 4
// 2 5
// 2 3
// 1 4
// 1 5
// 1 3
// 0 4
// 0 5
// 0 3
// 0 2
// 0 1
// 0 0

    }

    vector<vector<char>> updateBoard(vector<vector<char>>& board, vector<int>& click) {
        int clickedRow = click[0];
        int clickedCol = click[1];
        if(board[clickedRow][clickedCol] == 'M'){
            board[clickedRow][clickedCol] = 'X';
            return board;
        }

        dfs(board, clickedRow, clickedCol);
        return board;

    }
};
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