<p>You are given <code>row x col</code> <code>grid</code> representing a map where <code>grid[i][j] = 1</code> represents&nbsp;land and <code>grid[i][j] = 0</code> represents water.</p>

<p>Grid cells are connected <strong>horizontally/vertically</strong> (not diagonally). The <code>grid</code> is completely surrounded by water, and there is exactly one island (i.e., one or more connected land cells).</p>

<p>The island doesn&#39;t have &quot;lakes&quot;, meaning the water inside isn&#39;t connected to the water around the island. One cell is a square with side length 1. The grid is rectangular, width and height don&#39;t exceed 100. Determine the perimeter of the island.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img src="https://assets.leetcode.com/uploads/2018/10/12/island.png" style="width: 221px; height: 213px;" />
<pre>
<strong>Input:</strong> grid = [[0,1,0,0],[1,1,1,0],[0,1,0,0],[1,1,0,0]]
<strong>Output:</strong> 16
<strong>Explanation:</strong> The perimeter is the 16 yellow stripes in the image above.
</pre>

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

<pre>
<strong>Input:</strong> grid = [[1]]
<strong>Output:</strong> 4
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> grid = [[1,0]]
<strong>Output:</strong> 4
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>row == grid.length</code></li>
	<li><code>col == grid[i].length</code></li>
	<li><code>1 &lt;= row, col &lt;= 100</code></li>
	<li><code>grid[i][j]</code> is <code>0</code> or <code>1</code>.</li>
	<li>There is exactly one island in <code>grid</code>.</li>
</ul>

class Solution {
public:

    void dfs(vector<vector<int>>& grid,int i,int row,int j,int col,int &ans)
    {
         // Out of bounds or water cell, count as part of the perimeter
        if (i < 0 || j < 0 || i >= row || j >= col || grid[i][j] == 0) {
            ans++;
            return;
        }

         if (grid[i][j] == 2) {
            return;
        }

        grid[i][j] = 2;

        dfs(grid,i+1,row,j,col,ans);
        dfs(grid,i,row,j+1,col,ans);
        dfs(grid,i-1,row,j,col,ans);
        dfs(grid,i,row,j-1,col,ans);

        return;
    }
    int islandPerimeter(vector<vector<int>>& grid) {

        int row = grid.size();
        if(row == 0)
            return 0;
        
        int col = grid[0].size();

        int ans = 0;
        for(int i = 0; i<row; i++)
        {
            for(int j = 0; j<col; j++)
            {
                if(grid[i][j] ==1){
                dfs(grid,i,row,j,col,ans);
                }
            }
        }
        return ans;
    }
};
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