class Solution { public static int islandPerimeter(int[][] grid) { int perimeter = 0; for (int i = 0; i < grid.length; i++) { for (int j = 0; j < grid[i].length; j++) { if (grid[i][j] == 1) { if (i - 1 < 0 || grid[i - 1][j] == 0) perimeter++; if (j - 1 = grid.length || grid[i + 1][j] == 0) perimeter++; if (j + 1 >= grid[i].length || grid[i][j + 1] == 0) perimeter++; } } } return perimeter; } }