Advent Of Code

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An unofficial home for the advent of code community on programming.dev!

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.

AoC 2024

Solution Threads

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23	24	25

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console.log('Hello World')

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Ategon@programming.dev

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🦌 - 2024 DAY 2 SOLUTIONS -🦌 (programming.dev)

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

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Day 2: Red-Nosed Reports

Megathread guidelines

Keep top level comments as only solutions, if you want to say something other than a solution put it in a new post. (replies to comments can be whatever)
You can send code in code blocks by using three backticks, the code, and then three backticks or use something such as https://blocks.programming.dev if you prefer sending it through a URL

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What is this?: Here is a post with a large amount of details: https://programming.dev/post/22323136
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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[–] VegOwOtenks@lemmy.world 4 points 3 weeks ago (3 children)

Love to see your haskell solutions!

I am so far very amazed with the compactness of your solutions, your lessOne is very much mind-Bending. I have never used or seen <$> before, is it a monadic $?

Also I can't seem to find your logic for this safety condition: The levels are either all increasing or all decreasing, did you figure that it wasn't necessary?

[–] mschwennesen@discuss.tchncs.de 3 points 3 weeks ago

For the last point, it isn't needed since the differences between elements should be all positive or all negative for the report to be safe. This is tested with the combination of negate and gradual.

I am also enjoying these Haskell solutions. I'm still learning the language, so it's been cool to compare my solution with these and grow my understanding of Haskell.

[–] kintrix@linux.community 2 points 3 weeks ago* (last edited 3 weeks ago)

<$> is just fmap as an infix operator.

>>> fmap (+1) [1,2,3]
[2,3,4]
>>> (+1) <\$> [1,2,3]
[2,3,4]

[–] lwhjp@lemmy.sdf.org 1 points 3 weeks ago

Thanks! The other two posters already answered your questions, I think :)

Haskell makes it really easy to build complex operations out of simple functional building blocks, skipping a lot of boilerplate needed in some other languages. I find the compactness easier to read, but I realize that not everyone would agree.

BTW, I'm a relative Haskell newbie. I'm sure more experienced folks could come up with even more interesting solutions!