<p>You are given an <code>m x n</code> binary matrix <code>grid</code>. An island is a group of <code>1</code>&#39;s (representing land) connected <strong>4-directionally</strong> (horizontal or vertical.) You may assume all four edges of the grid are surrounded by water.</p>

<p>The <strong>area</strong> of an island is the number of cells with a value <code>1</code> in the island.</p>

<p>Return <em>the maximum <strong>area</strong> of an island in </em><code>grid</code>. If there is no island, return <code>0</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/05/01/maxarea1-grid.jpg" style="width: 500px; height: 310px;" />
<pre>
<strong>Input:</strong> grid = [[0,0,1,0,0,0,0,1,0,0,0,0,0],[0,0,0,0,0,0,0,1,1,1,0,0,0],[0,1,1,0,1,0,0,0,0,0,0,0,0],[0,1,0,0,1,1,0,0,1,0,1,0,0],[0,1,0,0,1,1,0,0,1,1,1,0,0],[0,0,0,0,0,0,0,0,0,0,1,0,0],[0,0,0,0,0,0,0,1,1,1,0,0,0],[0,0,0,0,0,0,0,1,1,0,0,0,0]]
<strong>Output:</strong> 6
<strong>Explanation:</strong> The answer is not 11, because the island must be connected 4-directionally.
</pre>

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

<pre>
<strong>Input:</strong> grid = [[0,0,0,0,0,0,0,0]]
<strong>Output:</strong> 0
</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;= 50</code></li>
	<li><code>grid[i][j]</code> is either <code>0</code> or <code>1</code>.</li>
</ul>

class Solution {
public:
    int bfs(vector<vector<int>>&g,int m,int n)
    {
        queue<vector<int>>q;
        int c=0;
        q.push({m,n});
        
        while(!q.empty())
        {   vector<int>x=q.front();
        q.pop();
        c++;
            int i=x[0];
            int j=x[1];
            g[i][j]=-1;
            if(i>0 && g[i-1][j]==1)
            {
              g[i-1][j]=-1;
              q.push({i-1,j});  
            }
            if(j>0 && g[i][j-1]==1)
            {
              g[i][j-1]=-1;
              q.push({i,j-1});  
            }
            if(j<g[0].size()-1 && g[i][j+1]==1)
            {
                g[i][j+1]=-1;
                q.push({i,j+1});
            }
            if(i<g.size()-1 && g[i+1][j]==1)
            {
                g[i+1][j]=-1;
                q.push({i+1,j});
            }
           
        }
        return c;
    }
    int maxAreaOfIsland(vector<vector<int>>& grid) {
        int ans=0;
       for(int i=0;i<grid.size();i++)
       {
        for(int j=0;j<grid[0].size();j++)
       {
        if(grid[i][j]==1)
        {
            ans=max(ans,bfs(grid,i,j));
        }
       }
       } 
       return ans;
    }
};
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