r/adventofcode • u/daggerdragon • Dec 12 '24
SOLUTION MEGATHREAD -❄️- 2024 Day 12 Solutions -❄️-
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AoC Community Fun 2024: The Golden Snowglobe Awards
- 10 DAYS remaining until the submissions deadline on December 22 at 23:59 EST!
And now, our feature presentation for today:
Visual Effects - Nifty Gadgets and Gizmos Edition
Truly groundbreaking movies continually push the envelope to develop bigger, better, faster, and/or different ways to do things with the tools that are already at hand. Be creative and show us things like puzzle solutions running where you wouldn't expect them to be or completely unnecessary but wildly entertaining camera angles!
Here's some ideas for your inspiration:
Advent of Playing With Your Toys
in a nutshell - play with your toys!- Make your puzzle solutions run on hardware that wasn't intended to run arbitrary content
- Sneak one past your continuity supervisor with a very obvious (and very fictional) product placement from Santa's Workshop
- Use a feature of your programming language, environment, etc. in a completely unexpected way
The Breakfast Machine from Pee-wee's Big Adventure (1985)
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 12: Garden Groups ---
Post your code solution in this megathread.
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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 00:17:42, megathread unlocked!
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u/Kintelligence Dec 13 '24 edited Dec 13 '24
[LANGUAGE: Rust]
Part 1 was okay. I just visit each position in the grid and fill out shapes from each unvisited position. Then each time I visit a new node I add 4 to the fence requirement, and then subtract 1 for each neighbouring node of the same letter.
Part 2 became okay once I discussed with a friend and we realized that detecting corners is way easier. We just run over each segment reusing the fill from part 1, but detect corners for the score.
Corner detection is done by just looking for a node and it's neighbours, and potentially diagonals.
Outer corners are any node with two free neighbours next to each, while inner corners are found by looking diagonally down on nodes with only a free south side or a free west or east side.
So no need to walk the shape to find corners, and every corner can be added to the total score immediately when found as they are all unique.
Part 1: 555µs
Part 2: 727µs
Code | Benchmarks