Create 463. Island Perimeter (#459)

Author: Chayandas07

463. Island Perimeter

@@ -0,0 +1,25 @@
+class Solution
+{
+public:
+    int islandPerimeter(vector<vector<int>> &grid)
+    {
+        int perimeter = 0, row = grid.size(), column = grid[0].size();
+        for (int i = 0; i < row; i++)
+        {
+            for (int j = 0; j < column; j++)
+            {
+                if (grid[i][j] == 0)
+                    continue;
+                // Either top row, or row above is water
+                perimeter += (i == 0 || grid[i - 1][j] == 0) +
+                       // Either end row or the row after is water
+                       (i == row - 1 || grid[i + 1][j] == 0) +
+                       // Either first column or column behind is water
+                       (j == 0 || grid[i][j - 1] == 0) +
+                       // Either last column or the column after is water
+                       (j == column - 1 || grid[i][j + 1] == 0);
+            }
+        }
+        return perimeter;
+    }
+};