<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<bool>>&visited,vector<vector<int>>& grid,int row,int col,int&count){

        visited[row][col] = true;

        int drow[] = {-1,0,1,0};
        int dcol[] = {0,1,0,-1};

        for(int i = 0;i<4;i++){
            int nrow = row + drow[i];
            int ncol = col + dcol[i];

            if(nrow>=0 && nrow<grid.size() && ncol>=0 && ncol<grid[0].size() && grid[nrow][ncol]==1){
                if(visited[nrow][ncol]==false)
                dfs(visited,grid,nrow,ncol,count);
            }
            else
            {
                count++;
            }
        }

    }

    int islandPerimeter(vector<vector<int>>& grid) {
        
        int n = grid.size();
        int m = grid[0].size();

        vector<vector<bool>> visited(n,vector<bool>(m,false));

        int row = -1;
        int col = -1;

        for(int i=0;i<grid.size();i++){
            for(int j=0;j<grid[0].size();j++){

                if(grid[i][j]==1){
                  row = i;
                  col = j;
                  break;
                }
            }
        }

        int count = 0;

        dfs(visited,grid,row,col,count);

        return count;
    }
};
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