Rotting Oranges

Moderate

0/80

Average time to solve is 20m

Contributed by

122 upvotes

Asked in companies

Problem statement

You have been given a grid containing some oranges. Each cell of this grid has one of the three integers values:

Value 0 - representing an empty cell.

Value 1 - representing a fresh orange.

Value 2 - representing a rotten orange.

Every second, any fresh orange that is adjacent(4-directionally) to a rotten orange becomes rotten.

Your task is to find out the minimum time after which no cell has a fresh orange. If it's impossible to rot all the fresh oranges then print -1.

Note:

1. The grid has 0-based indexing.
2. A rotten orange can affect the adjacent oranges 4 directionally i.e. Up, Down, Left, Right.

Detailed explanation ( Input/output format, Notes, Images )

Input Format:

The first line of input contains two single space-separated integers 'N' and 'M' representing the number of rows and columns of the grid respectively.

The next 'N' lines contain 'M' single space-separated integers each representing the rows of the grid.

Output Format:

The only line of output contains a single integer i.e. The minimum time after which no cell has a fresh orange. 

If it's impossible to rot all oranges, print -1.

Note:

You are not required to print the expected output, it has already been taken care of. Just implement the function.

Constraints:

1 <= N <= 500
1 <= M <= 500
0 <= grid[i][j] <= 2

Time Limit: 1 sec

Sample Input 1:

Sample Output 1:

Explanation of Sample Input 1:

Minimum 4 seconds are required to rot all the oranges in the grid as shown below.

Sample Input 2:

Sample Output 2:

-1

Explanation of Sample Input 2:

The bottom left corner fresh orange (row 2, column 0) has no adjacent oranges. Hence, it's impossible to rot it.

Console