No frills Python, no tests, no typing, no docs, if __name__ == '__main__, etc.
- Day 1: Trebuchet?! — Unusually hard for Day 1, especially Part 2 because of overlapping numeral names, e.g.
oneight, where theeightis wanted but regex (say) picks up theone. Could easily refactor to avoid using regex. SLOC: 20. - Day 2: Cube Conundrum — Fairly easy and quite enjoyable. Wrote a class, which made part 2 very easy to implement. SLOC: 32.
- Day 3: Gear Ratios — One of the classic grid problems, but a bit more interesting than usual with a many-to-one mapping of labels to symbols. I did not realize until afterwards that all the gears were
*symbols; fortunately no other symbols had multiple labels. SLOC: 48. - Day 4: Scratchcards — Fun problem, and thankfully all the special effects were only propagated forwards so a simple queue sufficed with no
whileloop needed. Used a class for a scratchcard and did not regret it. SLOC: 22. - Day 5: If You Give A Seed A Fertilizer — The first of the "computationally intractable part 2" problems. Considered trying to invert everything and work back through the maps, but in the end went with horribly hacky solution involving plotting ranges and extrapolating. Probably could be treated as an optimization problem with some random sampling, but I assume there's a smart solution. SLOC: 31 (but solution is not complete because it involved manual hacking).
- Day 6: Wait For It — Easy and (for me) very quick to solve. Part 2 seemed like it would be intractable but brute force did the trick in a few seconds. SLOC: 17.
- Day 7: Camel Cards — A simplified poker game (no straight or flush), with wild cards in Part 2. My solution for Part 1 was fairly fun and compact, but Part 2 blew up quite a bit when I realized that the hand type was from the 'wild' hand, but the rank was from the 'real' hand (with adjusted strength for the wild card). SLOC: 62.
Mostly fun so far. Weirdly this year I have only run my code on the given example once (and it passed, while the real data was not — classic).
- Day 8: Haunted Wasteland — Fun, not too hard graph problem. Part 2 was again the classic too-expensive problem, but after only a bit of flailing (thinking I could find a loop), I realized I could count each path separately and find the lowest common multiple. SLOC: 24.
- Day 9: Mirage Maintenance — Cool prediction task with discrete derivatives and a sort of Pascal's triangle based on subtraction. Tripped over the 'cumulative difference' function a bit but overall today was one of the easy days. SLOC: 19.
- Day 10: Pipe Maze – Scared off by the description and a Sunday meant I got to this late, but with time to think. Realized no scanning was needed, but only following the turns. Still have some hacky hard-coded initial conditions, but whatevs. Part 2 was so nearly super-easy, but my idea of using the shoelace formula got tangled. Although I caved and used Shapely to get the area initially, I eventually got it working. Used Pick's theorem to get the integer point area from the polygon area. Cute. SLOC: 35.
- Day 11: Cosmic Expansion — One of the simpler grid problems. I anticipated the nonsense to come in Part 2 so had the brainwave of using a dict right from the start, instead of making the expanded grid. Embarrassingly procedural solution, totally naive to the extent that I even parse the entire dataset twice (got into deep water when I tried to be smarter). SLOC: 32.
- Day 12: Hot Springs — Not getting it 😭 SLOC: 32 (part 1 only).
- Day 13: Point of Incidence — Started with a binary to decimal conversion to compare patterns of numbers, but in the end went with the strings themselves and a Levenshtein distance comparison... then realized I could just count the non-equal characters, ha. SLOC: 31.
- Day 14:Parabolic Reflector Dish — Sliding rocks around, quite fun. Used imaginary numbers as usual, so rotating the board felt easier (multiply by imaginary i) than changing the rock movement direction. Part 2 runs veeery slowly, even just to do the 200-ish iterations needed for the stability to emerge — then modulo math to extrapolate. Incomplete solution because I did that bit manually. SLOC: 33.
- Day 15: Lens Library — What seemed at first like very complex instructions turned out to be quite simple. No elegance in my solution, no need for speed, just do the thing. SLOC: 33.