Advent Of Code

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An unofficial home for the advent of code community on programming.dev! Other challenges are also welcome!

Advent of Code is an annual Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like.

Everybody Codes is another collection of programming puzzles with seasonal events.

AoC 2025

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Credits

Icon base by Lorc under CC BY 3.0 with modifications to add a gradient

console.log('Hello World')

founded 2 years ago

MODERATORS

Ategon@programming.dev

Sigmatics@lemmy.ca

CameronDev@programming.dev

hades@programming.dev

💃 - 2025 DAY 3 SOLUTIONS - 💃 (programming.dev)

submitted 3 weeks ago by CameronDev@programming.dev to c/advent_of_code@programming.dev

33 comments fedilink hide all child comments

Day 3: Lobby

Megathread guidelines

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FAQ

What is this?: Here is a post with a large amount of details: https://programming.dev/post/6637268
Where do I participate?: https://adventofcode.com/
Is there a leaderboard for the community?: We have a programming.dev leaderboard with the info on how to join in this post: https://programming.dev/post/6631465

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[–] mykl@lemmy.world 6 points 3 weeks ago* (last edited 3 weeks ago) (1 children)

Uiua

You can run this in Uiua Pad

"987654321111111\n811111111111119\n234234234234278\n818181911112111"
⊜∘⊸≠@\n
Jolt ← ⍥(⊙⊃⋅∘∘+1⟜(⊃(˜⊡|˜↘⊙+₁)⍜↘⟜(˜⨂⊸/↥)))⟜(+1¯)
∩/+⊃≡(⋕Jolt2)≡(⋕Jolt12)

::: spoiler Explanation You're always looking for the highest digit far enough from the end of the string that there's space to pick the remaining number of digits. So the algorithm is very straightforward: just temporarily exclude the last n-1 characters off the end of the string and look for the first instance of the largest digit in that substring, store that char and behead the string at that point. Repeat n times.

[–] CameronDev@programming.dev 3 points 3 weeks ago (1 children)

I cant understand your code, but your description of your algorithm was very clear.

[–] mykl@lemmy.world 2 points 3 weeks ago

Thanks, although it only really became clear after I'd written it. I am thinking about doing a more detailed explainer post based on one day's answer to help people get a feel for it.