In this tutorial, i am going to discuss a very interesting problem rotting oranges (minimum time required to rot all fresh oranges).
Given an m*n grid where each cell in the matrix can have values 0, 1 or 2.
0 represents an empty cell
1 represents cells have fresh oranges
2 represents cells have rotten oranges
Every minute, any fresh orange that is 4-directionally adjacent to a rotten orange becomes rotten.
Return the minimum number of minutes that must elapse until no cell has a fresh orange. If this is impossible, return -1.