It was, of course, an AI-generated solution; they posted it here: https://web.archive.org/web/20241201052156/https://github.com/qianxyz/advent-of-code/commit/64

It was, of course, an AI-generated solution; they posted it here: https://web.archive.org/web/20241201052156/https://github.com/qianxyz/advent-of-code/commit/6458076f5782790f8878a957add96093e72ce5a2 https://web.archive.org/web/20241201052156/https://github.co... Later, after being called out on it, they posted an apology to their GitHub profile (https://web.archive.org/web/20241201064816/https://github.com/qianxyz https://web.archive.org/web/20241201064816/https://github.co...): "If you are here from the AoC leaderboard, I apologize for not reading the FAQ. Won't happen again." Both the repo and that message are now gone.