<p>You are given an <code>m x n</code> binary grid <code>grid</code> where <code>1</code> represents land and <code>0</code> represents water. An <strong>island</strong> is a maximal <strong>4-directionally</strong> (horizontal or vertical) connected group of <code>1</code>&#39;s.</p>

<p>The grid is said to be <strong>connected</strong> if we have <strong>exactly one island</strong>, otherwise is said <strong>disconnected</strong>.</p>

<p>In one day, we are allowed to change <strong>any </strong>single land cell <code>(1)</code> into a water cell <code>(0)</code>.</p>

<p>Return <em>the minimum number of days to disconnect the grid</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/12/24/land1.jpg" style="width: 500px; height: 169px;" />
<pre>
<strong>Input:</strong> grid = [[0,1,1,0],[0,1,1,0],[0,0,0,0]]

<strong>Output:</strong> 2
<strong>Explanation:</strong> We need at least 2 days to get a disconnected grid.
Change land grid[1][1] and grid[0][2] to water and get 2 disconnected island.
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/12/24/land2.jpg" style="width: 404px; height: 85px;" />
<pre>
<strong>Input:</strong> grid = [[1,1]]
<strong>Output:</strong> 2
<strong>Explanation:</strong> Grid of full water is also disconnected ([[1,1]] -&gt; [[0,0]]), 0 islands.
</pre>

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

<ul>
	<li><code>m == grid.length</code></li>
	<li><code>n == grid[i].length</code></li>
	<li><code>1 &lt;= m, n &lt;= 30</code></li>
	<li><code>grid[i][j]</code> is either <code>0</code> or <code>1</code>.</li>
</ul>

class Solution {
    void printGrid(vector<vector<int>> &grid) {
        for(auto a: grid) {
            for(auto b: a) {
                cout<<b<<" ";
            }
            cout<<endl;
        }
        cout<<endl;
    }
    void sinkIsland(vector<vector<int>> &grid, int r, int c) {
        if(r < 0 || c < 0 || r >= grid.size() || c >= grid[0].size() || !grid[r][c]) return;
        grid[r][c] = 0;
        sinkIsland(grid, r+1, c);
        sinkIsland(grid, r, c+1);
        sinkIsland(grid, r-1, c);
        sinkIsland(grid, r, c-1);
    }
    int countIslands(vector<vector<int>> grid) {
        int res = 0;
        printGrid(grid);
        for(int i=0; i<grid.size(); i++) {
            for(int j=0; j<grid[0].size(); j++) {
                if(!grid[i][j]) continue;
                ++res;
                sinkIsland(grid, i, j);
            }
        }
        cout<<endl<<res<<endl;
        return res;
    }
public:
    int minDays(vector<vector<int>>& grid) {
        int val = 2;
        if(countIslands(grid) != 1) return 0;
        for(int i=0; i<grid.size(); i++) {
            for(int j=0; j<grid[0].size(); j++) {
                if(!grid[i][j]) continue;
                grid[i][j] = 0;
                if(countIslands(grid) != 1) return 1;
                grid[i][j] = 1;
            }
        }
        return 2;
    }
};
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