<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:
    bool visited[55][55];
    vector<int> d[4] = {{1, 0}, {-1, 0}, {0, 1}, {0, -1}};
    int area = 0;
    bool isValid(int i, int j, int row, int col) {
        if (i < 0 || i >= row || j < 0 || j >= col) {
            return false;
        } else {
            return true;
        }
    }
    void bfs(int si, int sj, int row, int col, vector<vector<int>>& grid) {
        int count = 0;
        queue<pair<int, int>> q;
        q.push({si, sj});
        visited[si][sj] = true;
        count++;
        while (!q.empty()) {
            pair<int, int> par = q.front();
            q.pop();
            int si = par.first;
            int sj = par.second;
            for (int i = 0; i < 4; i++) {
                int ci = si + d[i][0];
                int cj = sj + d[i][1];
                if (isValid(ci, cj, row, col) && !visited[ci][cj] && grid[ci][cj] == 1) {
                    q.push({ci, cj});
                    visited[ci][cj] = true;
                    count++;
                }
              
            }
        }
        area=max(area, count);
    }
    int maxAreaOfIsland(vector<vector<int>>& grid) {
         int row = grid.size();
        int col = grid[0].size();
        memset(visited, false, sizeof(visited));
        for(int i=0; i<row;i++)
        {
            for(int j=0; j<col; j++)
            {
                if(!visited[i][j] && grid[i][j] == 1)
                {
                    bfs(i, j, row, col,grid);
                    cout<<i<<" "<<j<<" "<<area<<endl;
                }
            }
        }
        return area;
    }
};
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