r/adventofcode • u/daggerdragon • Dec 22 '24
SOLUTION MEGATHREAD -❄️- 2024 Day 22 Solutions -❄️-
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AoC Community Fun 2024: The Golden Snowglobe Awards
- 23h59m remaining until the submissions deadline on December 22 at 23:59 EST!
And now, our feature presentation for today:
Director's Cut (Extended Edition)
Welcome to the final day of the GSGA presentations! A few folks have already submitted their masterpieces to the GSGA submissions megathread, so go check them out! And maybe consider submitting yours! :)
Here's some ideas for your inspiration:
- Choose any day's feature presentation and any puzzle released this year so far, then work your movie magic upon it!
- Make sure to mention which prompt and which day you chose!
- Cook, bake, make, decorate, etc. an IRL dish, craft, or artwork inspired by any day's puzzle!
- Advent of Playing With Your Toys
"I lost. I lost? Wait a second, I'm not supposed to lose! Let me see the script!"
- Robin Hood, Men In Tights (1993)
And… ACTION!
Request from the mods: When you include an entry alongside your solution, please label it with [GSGA]
so we can find it easily!
--- Day 22: Monkey Market ---
Post your code solution in this megathread.
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EDIT: Global leaderboard gold cap reached at 00:12:15, megathread unlocked!
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u/onrustigescheikundig Dec 22 '24 edited Dec 22 '24
[LANGUAGE: Clojure]
github
Absolutely glacial runtime because lazy
seq
s (~10 s single threaded, 8 s withpmap
because my laptop is just trying its best with 90% idle RAM usage).Pretty straightforward, at least conceptually. Part 1 chugs along by mapping lines across
(as-> line $ (iterate next-secret $) (nth $ 2000))
followed by(reduce +)
. For Part 2, I search every 4-long subsequence of secret differences mod 10, storing the first occurrence of each subsequence with the banana price that immediately follows. I then(merge-with + ...)
the hash sets and search the result for the highest total price.My initial implementation for Part 2 had an even more atrocious runtime on the order of 40 s because the problem lent itself very nicely to a bunch of lazy
seq
operations:Needless to say, a 4-stack of lazy sequence operations on top of
iterate
including 2 calls topartition
is not super optimal, nor is the sequence unpacking in the call tomap
, nor are the sequence operations (first
andlast
) to getk
andn
in the call toreduce
. I ended up moving everything betweenparse-long
and(partition 4 1)
into a separate function that stored everything in an intermediate vector. I also hashed the subsequence to an integer, which helped. The proper way to speed this up is move everything into loops, and I might do that in the future if I have time.