994. Rotting Oranges
Medium
30 Points
Array
Breadth-First Search
Matrix
You are given an m x n grid where each cell can have one of three values:
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
Explanation: 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
Explanation: Since there are already no fresh oranges at minute 0, the answer is just 0.
Constraints
m == grid.lengthn == grid[i].length1 <= m, n <= 10grid[i][j] is 0, 1, or 2.
994. Rotting Oranges
Medium
30 Points
Array
Breadth-First Search
Matrix
You are given an m x n grid where each cell can have one of three values:
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
Explanation: 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
Explanation: Since there are already no fresh oranges at minute 0, the answer is just 0.
Constraints
m == grid.lengthn == grid[i].length1 <= m, n <= 10grid[i][j] is 0, 1, or 2.