<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) {
        int ans = 0; // Variable to store the maximum area of an island
        m = grid.size(); // Number of rows in the grid
        n = grid[0].size(); // Number of columns in the grid

        // Iterate over every cell in the grid
        for(int i = 0; i < m; i++){
            for(int j = 0; j < n; j++){
                // If the current cell is part of an island (i.e., value is 1)
                if(grid[i][j] == 1){
                    // Perform DFS to calculate the area of the island and update the maximum area
                    ans = max(ans, dfs(i, j, grid));
                }
            }
        }
        return ans; // Return the maximum area found
    }
private:
    int m, n; // Dimensions of the grid

    // DFS function to calculate the area of an island
    int dfs(int i, int j, vector<vector<int>>& grid){
        // Base case: Check if the current cell is out of bounds or water
        if(i < 0 || j < 0 || i >= m || j >= n || grid[i][j] == 0) return 0;

        // Mark the current cell as visited by setting it to 0
        grid[i][j] = 0;

        // Calculate the area by visiting all four adjacent cells (up, down, right, left)
        return 1 + dfs(i - 1, j, grid) + // Up
                   dfs(i + 1, j, grid) + // Down
                   dfs(i, j + 1, grid) + // Right
                   dfs(i, j - 1, grid);  // Left
    }
};

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