solves island perimeter

Author: anishLearnsToCode

README.md

@@ -122,7 +122,7 @@
 | 455 | [Assign Cookies](https://leetcode.com/problems/assign-cookies) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](src/AssignCookies.java) [![Python](https://img.icons8.com/color/35/000000/python.png)](python/assign_cookies.py)|
 | 459 | [Repeated Substring Pattern](https://leetcode.com/problems/repeated-substring-pattern) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](src/RepeatedSubstringPattern.java) [![Python](https://img.icons8.com/color/35/000000/python.png)](python/repeated_substring_pattern.py) |
 | 461 | [Hamming Distance](https://leetcode.com/problems/hamming-distance) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](src/HammingDistance.java) [![Python](https://img.icons8.com/color/35/000000/python.png)](python/hamming_distance.py) |
-| 463 | [Island Perimeter](https://leetcode.com/problems/island-perimeter) | Easy | |
+| 463 | [Island Perimeter](https://leetcode.com/problems/island-perimeter) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](src/IslandPerimeter.java) [![Python](https://img.icons8.com/color/35/000000/python.png)](python/island_perimeter.py) |
 | 475 | [Heaters](https://leetcode.com/problems/heaters) | Easy | |
 | 476 | [Number Complement](https://leetcode.com/problems/number-complement) | Easy | |
 | 482 | [License Key Formatting](https://leetcode.com/problems/license-key-formatting) | Easy | |

python/island_perimeter.py

@@ -0,0 +1,23 @@
+from typing import List
+
+
+class Solution:
+    def islandPerimeter(self, grid: List[List[int]]) -> int:
+        perimeter, rows, columns = 0, len(grid), len(grid[0])
+        for row in range(rows):
+            for column in range(columns):
+                if grid[row][column] == 1:
+                    perimeter += 4 - self.surroundedBy(grid, row, column)
+        return perimeter
+
+    def surroundedBy(self, grid: List[List[int]], row: int, column: int) -> int:
+        surrounded = 0
+        if row - 1 >= 0 and grid[row - 1][column] == 1:
+            surrounded += 1
+        if column + 1 < len(grid[0]) and grid[row][column + 1] == 1:
+            surrounded += 1
+        if row + 1 < len(grid) and grid[row + 1][column] == 1:
+            surrounded += 1
+        if column - 1 >= 0 and grid[row][column - 1] == 1:
+            surrounded += 1
+        return surrounded

src/IslandPerimeter.java

@@ -0,0 +1,30 @@
+public class IslandPerimeter {
+    public int islandPerimeter(int[][] grid) {
+        int perimeter = 0;
+        for (int row = 0 ; row < grid.length ; row++) {
+            for (int column = 0 ; column < grid[row].length ; column++) {
+                if (grid[row][column] == 1) {
+                    perimeter += 4 - surroundedBy(grid, row, column);
+                }
+            }
+        }
+        return perimeter;
+    }
+
+    private static int surroundedBy(int[][] grid, int row, int column) {
+        int surrounded = 0;
+        if (row - 1 >= 0 && grid[row - 1][column] == 1) {
+            surrounded++;
+        }
+        if (column + 1 < grid[0].length && grid[row][column + 1] == 1) {
+            surrounded++;
+        }
+        if (row + 1 < grid.length && grid[row + 1][column] == 1) {
+            surrounded++;
+        }
+        if (column - 1 >= 0 && grid[row][column - 1] == 1) {
+            surrounded++;
+        }
+        return surrounded;
+    }
+}