Rotting Oranges

arraybreadth-first searchmatrix

Problem Statement

You are given an m x n grid where each cell can have one of three values:

0 representing an empty cell,

1 representing a fresh orange, or

2 representing 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 .

Examples

Example 1

Input: grid = [[2,1,1],[1,1,0],[0,1,1]]
Output: 4

Example 2

Input: grid = [[2,1,1],[0,1,1],[1,0,1]]
Output: -1
The orange in the bottom left corner (row 2, column 0) is never rotten, because rotting only happens 4-directionally.

Example 3

Input: grid = [[0,2]]
Output: 0
Since there are already no fresh oranges at minute 0, the answer is just 0.

Constraints

m == grid.length

n == grid[i].length

1 <= m, n <= 10

grid[i][j] is 0 , 1 , or 2 .

🤔

Medium

Difficulty

Topic Info

ModuleDSA

CategoryArray

Sub-topicBreadth-First Search