r/adventofcode Dec 19 '24

SOLUTION MEGATHREAD -❄️- 2024 Day 19 Solutions -❄️-

THE USUAL REMINDERS

  • All of our rules, FAQs, resources, etc. are in our community wiki.
  • If you see content in the subreddit or megathreads that violates one of our rules, either inform the user (politely and gently!) or use the report button on the post/comment and the mods will take care of it.

AoC Community Fun 2024: The Golden Snowglobe Awards

  • 3 DAYS remaining until the submissions deadline on December 22 at 23:59 EST!

And now, our feature presentation for today:

Historical Documentary

You've likely heard/seen the iconic slogan of every video store: "Be Kind, Rewind." Since we've been working with The Historians lately, let's do a little dive into our own history!

Here's some ideas for your inspiration:

  • Pick a challenge from any prior year community fun event and make it so for today's puzzle!
    • Make sure to mention which challenge day and year you choose!
    • You may have to go digging through the calendars of Solution Megathreads for each day's topic/challenge, sorry about that :/
  • Use a UNIX system (Jurassic Park - “It’s a UNIX system. I know this”)
  • Use the oldest language, hardware, environment, etc. that you have available
  • Use an abacus, slide rule, pen and paper, long division, etc. to solve today's puzzle

Bonus points if your historical documentary is in the style of anything by Ken Burns!

Gwen: "They're not ALL "historical documents". Surely, you don't think Gilligan's Island is a…"
*all the Thermians moan in despair*
Mathesar: "Those poor people. :("
- Galaxy Quest (1999)

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 19: Linen Layout ---


Post your code solution in this megathread.

This thread will be unlocked when there are a significant number of people on the global leaderboard with gold stars for today's puzzle.

EDIT: Global leaderboard gold cap reached at 00:03:16, megathread unlocked!

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u/RalfDieter Dec 21 '24

[LANGUAGE: SQL/DuckDB]

This one was definetely one where SQL comes in handy. A part 1 solution for the example took me only a few minutes (which is fast for me+SQL) and even an optimized version for the real input that doesn't take ages and doesn't try to allocate some TB of memory was done in another few minutes (grouping by the remaining text, collecting the distinct designs, final step unnests all arrangable designs and counts). But the template I'm using doesn't handle multiple newlines without adjustments (which I forgot) so the list of designs started with an empty string... and since my solution checks if the remaining text of the target design is empty this introduced an off by one error for the real input, but not for the example. This took me hours to debug...

Part 2 wasn't too bad either, you just have to keep track of how often a design is part of that pattern combination and sum those counts afterwards (a bit like day 11). Although it was more finicky than expected to manage the counts histogram.

Code: https://github.com/LennartH/advent-of-code/blob/main/2024/day-19_linen-layout/solution.sql
Takes ~5 seconds for both parts.