island-perimeter.md

<p>You are given a map in form of a two-dimensional integer grid where 1 represents land and 0 represents water.</p>

<p>Grid cells are connected horizontally/vertically (not diagonally). The grid 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; (water inside that 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><b>Example:</b></p>

<pre>
<strong>Input:</strong>
[[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 below:

<img src="https://assets.leetcode.com/uploads/2018/10/12/island.png" style="width: 221px; height: 213px;" />
</pre>