We don't have to use the visited array. We can update the input array to mark nodes.

Almost all of the questions under the Island Pattern can be solved without using the visited array.

However, sometime, the interviewer might not like if you change the input array. Mo...

I really liked the bitwise operation you used there! I would watch out though for people who may not understand exactly what that means.

private static boolean closedIsland(int[][] matrix, int r, int c) { //this condition will return false if there are any 1s in the edges of the matrix //which will result in isClosed = false if(r < 0 || r >= matrix.length || c < 0 || c >= matrix[0].length) { return false...