<p>You are given an <code>m x n</code> matrix <code>board</code> containing <strong>letters</strong> <code>&#39;X&#39;</code> and <code>&#39;O&#39;</code>, <strong>capture regions</strong> that are <strong>surrounded</strong>:</p>

<ul>
	<li><strong>Connect</strong>: A cell is connected to adjacent cells horizontally or vertically.</li>
	<li><strong>Region</strong>: To form a region <strong>connect every</strong> <code>&#39;O&#39;</code> cell.</li>
	<li><strong>Surround</strong>: The region is surrounded with <code>&#39;X&#39;</code> cells if you can <strong>connect the region </strong>with <code>&#39;X&#39;</code> cells and none of the region cells are on the edge of the <code>board</code>.</li>
</ul>

<p>A <strong>surrounded region is captured</strong> by replacing all <code>&#39;O&#39;</code>s with <code>&#39;X&#39;</code>s in the input matrix <code>board</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">board = [[&quot;X&quot;,&quot;X&quot;,&quot;X&quot;,&quot;X&quot;],[&quot;X&quot;,&quot;O&quot;,&quot;O&quot;,&quot;X&quot;],[&quot;X&quot;,&quot;X&quot;,&quot;O&quot;,&quot;X&quot;],[&quot;X&quot;,&quot;O&quot;,&quot;X&quot;,&quot;X&quot;]]</span></p>

<p><strong>Output:</strong> <span class="example-io">[[&quot;X&quot;,&quot;X&quot;,&quot;X&quot;,&quot;X&quot;],[&quot;X&quot;,&quot;X&quot;,&quot;X&quot;,&quot;X&quot;],[&quot;X&quot;,&quot;X&quot;,&quot;X&quot;,&quot;X&quot;],[&quot;X&quot;,&quot;O&quot;,&quot;X&quot;,&quot;X&quot;]]</span></p>

<p><strong>Explanation:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/02/19/xogrid.jpg" style="width: 367px; height: 158px;" />
<p>In the above diagram, the bottom region is not captured because it is on the edge of the board and cannot be surrounded.</p>
</div>

<p><strong class="example">Example 2:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">board = [[&quot;X&quot;]]</span></p>

<p><strong>Output:</strong> <span class="example-io">[[&quot;X&quot;]]</span></p>
</div>

<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;= 200</code></li>
	<li><code>board[i][j]</code> is <code>&#39;X&#39;</code> or <code>&#39;O&#39;</code>.</li>
</ul>

class Solution {
public:
    vector<vector<int>> color;
    bool isSurr(int i, int j, vector<vector<char>>& board, char c, int cl) {
        color[i][j] = cl + 1;
        board[i][j] = c;
        bool flag = i == 0 || i == color.size() - 1 || j == 0 || j == color[0].size() - 1;
        cout << "i: " << i << " j: " << j << " flag: " << flag << endl;
        if (i - 1 >= 0 && color[i - 1][j] == cl && board[i - 1][j] != 'X')
            flag |= isSurr(i - 1, j, board, c, cl);
        if (i + 1 < color.size() && color[i + 1][j] == cl && board[i + 1][j] != 'X')
            flag |= isSurr(i + 1, j, board, c, cl);
        if (j - 1 >= 0 && color[i][j - 1] == cl && board[i][j - 1] != 'X')
            flag |= isSurr(i, j - 1, board, c, cl);
        if (j + 1 < color[0].size() && color[i][j + 1] == cl && board[i][j + 1] != 'X')
            flag |= isSurr(i, j + 1, board, c, cl);
        return flag;
    }
    void solve(vector<vector<char>>& board) {
        color.resize(board.size(), vector<int>(board[0].size()));
        for (int i = 0; i < board.size(); i++) {
            for (int j = 0; j < board[0].size(); j++) {
                if (!color[i][j] && board[i][j] != 'X') {
                    if (!isSurr(i, j, board, 'O', 0)) {
                        cout << "surr: " << i << " " << j << endl;
                        isSurr(i, j, board, 'X', 1);
                    }
                }
            }
        }
    }
};
24181