IslandPerimeter.java

package LeetcodePractice;

public class IslandPerimeter {
    public static void main(String[] args) {
        int[][] grid1 = {
            {0,1,0,0},
            {1,1,1,0},
            {0,1,0,0},
            {1,1,0,0}
        };
        System.out.println(islandPerimeter(grid1));

        int[][] grid2 = {{1}};
        System.out.println(islandPerimeter(grid2));

        int[][] grid3 = {{1,0}};
        System.out.println(islandPerimeter(grid3));
    }

    public static int islandPerimeter(int[][] grid) {
        int perimeter = 0;
        int rows = grid.length;
        int cols = grid[0].length;

        for (int i = 0; i < rows; i++) {
            for (int j = 0; j < cols; j++) {
                if (grid[i][j] == 1) {
                    perimeter += 4;

               
                    if (i < rows - 1 && grid[i + 1][j] == 1) {
                        perimeter -= 2;
                    }

                
                    if (j < cols - 1 && grid[i][j + 1] == 1) {
                        perimeter -= 2;
                    }
                }
            }
        }

        return perimeter;
    }
}