#depthfirstsearch

Problem Statement Count Sub Islands LeetCode Solution says that grid1 and grid2 contain only 0's (representing water) and 1's (representing land). The island means the group of 1's connected 4 directionally.An island in grid2 is considered a sub-island if there is an island in grid1 that contains all the cells that make up this island in grid2.Example 1:Input: grid1 = ,,,,], grid2 = ,,,,]Output: 3Explanation: In the picture above, the grid on the left is grid1 and the grid on the right is grid2. The 1s colored red in grid2 are those considered to be part of a sub-island. There are three sub-islands.Example 2:Input: grid1 = ,,,,], grid2 = ,,,,]Output: 2Explanation: In the picture above, the grid on the left is grid1 and the grid on the right is grid2. The 1s colored red in grid2 are those considered to be part of a sub-island. There are two sub-islands. Constraints: - m == grid1.length == grid2.length - n == grid1.length == grid2.length - 1