Code Room
CodingHardcod-g919
Subject Grid traversalLevel Senior–Staff~40 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

You walk a forest grid: 0 is an impassable obstacle, 1 is walkable ground, and any value > 1 is a tree of that height. You start at (0,0) and must cut all trees in strictly increasing order of height (no two trees share a height). Cutting a tree turns it into ground (1). Moving costs 1 per 4-directional step onto a walkable cell. Return the minimum total steps to cut every tree in order; if any tree is unreachable, return -1. The cell (0,0) is walkable (value >= 1) when you start.

Implement
cut_off_trees(forest: list[list[int]]) → int
Examples
in[[[1,2,3],[0,0,4],[7,6,5]]]out6
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.