<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 maxAreaOfIsland(vector<vector<int>>& grid) {
        if (grid.empty()){
            return 0;

        }
        int r=grid.size();
        int c=grid[0].size();
        int maxarea=0;
        vector<vector<int>>dir={{0,1},{0,-1},{-1,0},{1,0}};
        queue<pair<int,int>>q;
        for (int i=0;i<r;i++){
            for (int j=0;j<c;j++){
                int area=0;
                if (grid[i][j] ==1){
                    q.push({i,j});
                    area=1;
                    grid[i][j]=0;
                }
                while(!q.empty()){
                    int x=q.front().first;
                    int y=q.front().second;
                    q.pop();
                    for (auto d:dir){
                        int newx=x+d[0];
                        int newy=y+d[1];
                        if (newx>=0 && newy>=0 && newx<r && newy<c && grid[newx][newy]==1){
                            q.push({newx,newy});
                            area++;
                            grid[newx][newy]=0;

                        }
                    }
                    maxarea=max(maxarea,area);
                }
                
            }
        }
        return maxarea;
        
    }
};
33950