<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 m = grid.size();
        if(!m) return 0;
        int n = grid[0].size();
        if(!n) return 0;
        
        int max_area = 0;

        for(int r=0; r<m; r++){
            for(int c=0; c<n; c++){
                if(grid[r][c] == 1){
                    int cur_area = getComponentArea(grid, r, c);
                    max_area = max(max_area, cur_area);
                }
            }
        }

        return max_area;
    }

    int getComponentArea(vector<vector<int>>& grid, int r, int c){
        if (grid[r][c] == 0){
            return 0;
        } 

        grid[r][c] = 0;

        int m = grid.size();
        int n = grid[0].size();

        vector<pair<int,int>> directions = {{1,0}, {-1,0}, {0,1}, {0,-1}};
        int area = 1;

        for(pair<int,int> dir: directions){
            int next_r = r + dir.first;
            int next_c = c + dir.second;

            if(next_r>=0 && next_r<m && next_c>=0 && next_c<n){
                area += getComponentArea(grid, next_r, next_c);
            }
        }
        return area;
    }
};
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