Code Room
CodingMediumcod-g601
Subject CombinatoricsLevel Mid–Senior~25 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

An n-bit Gray code sequence is a permutation of the integers 0..2^n-1 that starts at 0 and in which every adjacent pair (including the wrap-around from last to first) differs in exactly one bit. Return the standard reflected Gray code sequence for a given n. n is between 0 and 16.

Implement
gray_code(n: int) → list[int]
Examples
in[2]out[0,1,3,2]
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.