<p>You are given <code>row x col</code> <code>grid</code> representing a map where <code>grid[i][j] = 1</code> represents 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't have "lakes", meaning the water inside isn'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't exceed 100. Determine the perimeter of the island.</p> <p> </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> </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 <= row, col <= 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>