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Advent of Code 2025

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Re: Advent of Code 2025

#141

Post by andriamanitra »

fainpul wrote: post #20

Opinion poll: Python is extremely suitable for these kind of problems. C++ is also often used, especially by competitive programmers. Which "non-mainstream" or even obscure languages are also well suited for AoC? Please list your weapon of choice and a short statement why it's well suited (not why you like it, why it's good for AoC).

I think Ruby is the ideal language for AoC:

* The expressive syntax helps keep the solutions short.

* It has extensive standard library with tons of handy methods for AoC style problems: Enumerable#each_cons, Enumerable#each_slice, Array#transpose, Array#permutation, ...

* The bundled "prime" gem (for generating primes, checking primality, and prime factorization) comes in handy for at least a few of problems each year.

* The tools for parsing inputs and string manipulation are a bit more ergonomic than what you get even in Python: first class regular expression syntax, String#scan, String#[], Regexp::union, ...

* You can easily build your solution step-by-step by chaining method calls. I would typically start with `p File.readlines("input.txt")` and keep executing the script after adding each new method call so I can inspect the intermediate results.

Re: Advent of Code 2025

#142

Post by wging »

Waterluvian wrote: post #43
squigz wrote: post #35

Earlier quoted context omitted.

It's really disheartening that the culture has changed so much someone would think doing AoC puzzles just for the fun of it is an unpopular stance :( Doing things for the fun of it, for curiosity's sake, for the thrill of solving a fun problem - that's very much alive, don't worry!

Eliminating the leaderboard might help. By measuring it as a race, it becomes a race, and now the goal is the metric. Maybe just have a cool advent calendar thingy like a digital tree that gains an ornament for each day you complete. Each ornament can be themed for each puzzle. Of course I hope it goes without saying that the creator(s) can do it however they want and we’re nothing but richer for it existing.

That 'digital tree' idea is similar to how AoC has always worked. There's a theme-appropriate ASCII graphic on the problem page that gains color and effects as you complete problems. It's not always a tree, but it was in 2015 (the first year), and in several other years at least one tree is visible. https://adventofcode.com/2015

Re: Advent of Code 2025

#143

Post by Aurornis »

qsort wrote: post #16

I'm actually pleasantly surprised to see a 2025 edition, last year being the 10th anniversary and the LLM situation with the leaderboard were solid indications that it would have been a great time to wrap it up and let somebody else carry the torch. It's only going to be 12 problems rather than 24 this year and there isn't going to be a gloabl leaderboard, but I'm still glad we get to take part in this fun Christmas…

A couple of the Slack/Discord groups I’m in do a local leaderboard with friends. It’s fun to do with a trusted group of people who are all in it for fun.

Re: Advent of Code 2025

#144

Post by wging »

incognito124 wrote: post #81
fainpul wrote: post #20

Opinion poll: Python is extremely suitable for these kind of problems. C++ is also often used, especially by competitive programmers. Which "non-mainstream" or even obscure languages are also well suited for AoC? Please list your weapon of choice and a short statement why it's well suited (not why you like it, why it's good for AoC).

If I remember correctly, one of the competitive programming experts from the global leaderboard made his own language, specifically tailored to help solve AoC problems: https://github.com/betaveros/noulith

Yes (or so I thought too!), but apparently no: https://blog.vero.site/post/noulith

(post title: "Designing a Programming Language to Speedrun Advent of Code", but starts off "The title is clickbait. I did not design and implement a programming language for the sole or even primary purpose of leaderboarding on Advent of Code. It just turned out that the programming language I was working on fit the task remarkably well.")

Re: Advent of Code 2025

#145

Post by christophilus »

fainpul wrote: post #20

Opinion poll: Python is extremely suitable for these kind of problems. C++ is also often used, especially by competitive programmers. Which "non-mainstream" or even obscure languages are also well suited for AoC? Please list your weapon of choice and a short statement why it's well suited (not why you like it, why it's good for AoC).

I’d say Clojure because it has great data manipulation utilities baked into the standard library.

Re: Advent of Code 2025

#146

Post by acedTrex »

bitbasher wrote: post #129
Jtsummers wrote: post #124

Earlier quoted context omitted.

You can always create a throwaway account on one of those services. It's not that hard.

You could, but you shouldn't have to. If you want to sign up for XYZ, you need to sign up for BigCorp, you need to add your phone number to verify your account, etc. No thanks.

You can log in with reddit, dont need a phone number for that one. And if you have an HN account you probably have a reddit acct lol

Re: Advent of Code 2025

#147

Post by cyberpunk »

mrkaye97 wrote: post #92
fainpul wrote: post #20

Opinion poll: Python is extremely suitable for these kind of problems. C++ is also often used, especially by competitive programmers. Which "non-mainstream" or even obscure languages are also well suited for AoC? Please list your weapon of choice and a short statement why it's well suited (not why you like it, why it's good for AoC).

I've been using Elixir, which has been wonderful, mostly because of how amazing the built in `Enum` library is for working on lists and maps (since the majority of AoC problems are list / map processing problems, at least for the first while)

Enum really does feel like a superpower sometimes. I’ll knock out some loop and then spend a few mins with h Enum. and realise it could’ve been one or two Enum functions.

Re: Advent of Code 2025

#148

Post by Aurornis »

letmetweakit wrote: post #112
quirino wrote: post #107

Small anecdote: In the IEEEXTREME university programming competition there are ~10k participating teams. Our university has a quite strong Competitive Programming program and the best teams usually rank in the top 100. Last year a team ranked 30 and it's wasn't even our strongest team (which didn't participate) This year none of our teams was able to get in the top 1000. I would estimate close to 99% of the teams in…

Man, those people using LLMs in competitive programming ... where's the fun in that? I don't get people for whom it's just about winning, I wish everyone would just have some basic form of dignity and respect.

I’m a very casual gamer but even I run into obvious cheaters in any popular online game all the time.

Cheating is rampant anywhere there’s an online competition. The cheaters don’t care about respecting others, they get a thrill out of getting a lot of points against other people who are trying to compete.

Even in the real world, my runner friends always have stories about people getting caught cutting trails and all of the lengths their running organizations have to go through now to catch cheaters because it’s so common.

The thing about cheaters in a large competition is that it doesn’t take many to crowd out the leaderboard, because the leaderboard is where they get selected out. If there are 1000 teams competing and only 1% cheat, that 1% could still fill the top 10.

Re: Advent of Code 2025

#149

Post by throwaway0123_5 »

Ekaros wrote: post #130
letmetweakit wrote: post #112

Earlier quoted context omitted.

Man, those people using LLMs in competitive programming ... where's the fun in that? I don't get people for whom it's just about winning, I wish everyone would just have some basic form of dignity and respect.

Weirdly I feel lot more accepting of LLMs in this type of environment than in making actual products. Point is doing things fast and correct enough. So in someways LLM is just one more tool. With products I want actual correctness. And not something thrown away.

Given what I understand about the nature of competitive programming competitions, using an LLM seems kind of like using a calculator in an arithmetic competition (if such a thing existed) or a dictionary in a spelling bee.

Re: Advent of Code 2025

#150

Post by zwnow »

losvedir wrote: post #84
zwnow wrote: post #3

> Should I use AI to solve Advent of Code puzzles? No. If you send a friend to the gym on your behalf, would you expect to get stronger? Advent of Code puzzles are designed to be interesting for humans to solve - no consideration is made for whether AI can or cannot solve a puzzle. If you want practice prompting an AI, there are almost certainly better exercises elsewhere designed with that in mind. And yet I expect…

Depends how you look at it. Some of my colleagues rave about Claude Code, so I was thinking about trying it out on these puzzles. In that sense it is "going to the gym", just for a different thing. Since I do AoC every year, I feel like it'll give me a good feel for Claude Code compared to my baseline. And it's not just "prompting", but figuring out a workflow with tests and brainstorming and iteration and all that.…

It 100% can do that. LLMs are trained on an unfathomable amount of data. Every AoC puzzle can be solved by identifying the algorithm behind it. Its Leetcode in a friendlier and more festive spirit.
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