<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 {
public:

    int check(vector<vector<int>> s,int n,int m){
        queue<pair<int,int>>q;

        for(int i=0;i<n;i++){
            int j=0;
            for(;j<m;j++){
                if(s[i][j]==1){
                    s[i][j]=0;
                    q.push({i,j});
                    break;
                }
            }
            if(j!=m)break;
        }

        if(q.size()==0){
            return 1;
        }

        pair<int,int>dir[]={{1,0},{0,1},{-1,0},{0,-1}};
        

        while(q.size()>0){
            auto pi=q.front();
            q.pop();
            for(auto z:dir){
                int x=pi.first+z.first;
                int y=pi.second+z.second;

                if(x<0||y<0||x>=n||y>=m||s[x][y]==0)continue;
                q.push({x,y});
                s[x][y]=0;
            }
        }

        for(int i=0;i<n;i++){
            for(int j=0;j<m;j++){
                if(s[i][j]==1){
                    return 1;
                }
            }
        }

        return 0;

    }

    int minDays(vector<vector<int>>& s) {
        
    
        int n=s.size();
        int m=s[0].size();
        if(check(s,n,m)){
           return 0; 
        }

        for(int i=0;i<n;i++){
            for(int j=0;j<m;j++){
                if(s[i][j]==1){
                    s[i][j]=0;
                    int f=check(s,n,m);

                    if(f==1){
                        return 1;
                    }
                    s[i][j]=1;

                }
            }
        }
        return 2;
    }


};
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