Code Room
CodingMedium
Question
Given an m x n matrix, return all its elements in diagonal order: start at the top-left and traverse anti-diagonals, alternating direction — the first diagonal goes up-right, the next down-left, and so on in a zig-zag. 1 <= m, n <= 100. Return a flat list of the values in that order.
Implement
diagonal_order(mat: list[list[int]]) → list[int]Examples
in
[[[1,2,3],[4,5,6],[7,8,9]]]out[1,2,4,7,5,3,6,8,9]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.
Learn the concepts
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.