aoc solutions

My original advent-of-code solutions in Python, tidied to varing degrees. (Since 2025 I've also solved here in Rust.)

I aim for intelligible solutions and will usually solve parts a and b separately. I won't force a combined solution at the expense of intelligibility, although I might use or add one (_comb) if part b is a natural evolution of part a or if part a can be easily extracted from part b.

After solving I might write a revised version to learn a better way of doing it or an alternative version to learn a different way of doing it (references included where these were inspired by someone else's solution).

The README for each year serves as a reference of the key features of each solution.

Useful references

ℹ️ Last revised references Dec 2025

• awesome-advent-of-code - the Awesome repo is pretty awesome, references to resources and solutions (by year / by language).
• advent-of-code-data - helper library for accessing puzzle data.
• aoc subreddit

Solutions

NB references to 'leaderboards' refers to the global leaderboards pre-2025.

• hyper-nutrino shares very competitive solutions and offers video explanations for each puzzle (hyper-nutrino is frequently found at or towards the top of the leaderboards). My go-to "this is how you should have done it".
• Jonathan Paulson can also be found towards the top of the leaderboards. Publishes original solutions and videos (here) of real-time submissions streamed with a delay. Videos include post-submission explanations.
• iKevinY a regular leaderboarder who publishes clear intelligible solutions.
• gahjelle frequently offers various solutions for a day, each offering a different approach.
• MasterMedo I've found some real gems here offering novel, efficient implementations. MasterMedo has offered solutions for most puzzles for nearly all years.
• mrphlip has offered solutions since 2019 and includes an .md file with explanatory notes for each puzzle! Even offers visualisations for some.

Solutions from previous years (not publishing in most recent years)

• mebeim offered a walkthrough of (nearly all) aoc solutions from 2019 through 2024.
• nthistle was a regular leaderboarder. Neil hasn't published solutions since 2022 although until 2024 he continued to post (delayed) real-time videos here of his often lightning quick solves, usually including an explanation at the end.
• Viliam Pucik doesn't usually do all the puzzles each year (and hasn't published solutions since 2023), although among those Viliam has solved I've found to be some of the best solutions I've seen anywhere (look at day 25 2022 and weep).
• oliver-ni was a regular leaderboarder who published solutions with minimal clean-up. Hasn't published solutions since 2024 day 15.