Rotting Oranges
You are given an m x n grid where each cell can have one of three values:
0representing an empty cell,1representing a fresh orange, or2representing a rotten orange.
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.
Example 1
2 1 1 1 1 0 0 1 1
Input
grid = [[2,1,1],[1,1,0],[0,1,1]]Output
4All fresh oranges become rotten after 4 minutes.
Example 2
2 1 1 0 1 1 1 0 1
Input
grid = [[2,1,1],[0,1,1],[1,0,1]]Output
-1The orange in the bottom left corner (row 2, column 0) is never rotten, because rotting only happens 4-directionally.
Constraints
- m == grid.length
- n == grid[i].length
- 1 <= m, n <= 10
- grid[i][j] is 0, 1, or 2.