Code Room
CodingMediumcod-g105
Subject QueuesLevel Mid–Senior~30 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

You are given an m x n grid where each cell is 0 (empty), 1 (fresh orange), or 2 (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. The grid has 1 to 100 rows and 1 to 100 columns.

Implement
oranges_rotting(grid: list[list[int]]) → int
Examples
in[[[2,1,1],[1,1,0],[0,1,1]]]out4
What a strong answer looks like

State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.

Vibe coding: describe the solution in plain language (or narrate it) and the coach grades your approach. Generating runnable code from your description is coming next.

Run or narrate your approach, then ask the coach.