Rotting Oranges Problem Statement

You are given a grid containing oranges where each cell of the grid can contain one of the three integer values:

• 0 - representing an empty cell
• 1 - representing a fresh orange
• 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 the minimum time required after which no cell contains a fresh orange. If it is impossible to rot all the fresh oranges, return -1.

Note:

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

Example:

Input:

N = 3, M = 3
grid = [
  [2, 1, 1],
  [1, 1, 0],
  [0, 1, 1]
]

Output:

4

Explanation:

After 4 seconds, all fresh oranges become rotten.

Constraints:

• 1 <= N <= 500
• 1 <= M <= 500
• 0 <= grid[i][j] <= 2
• Time Limit: 1 sec