579 comments

[ 4.1 ms ] story [ 427 ms ] thread
9 seconds to get both stars is absolutely insane - there had to be some AI assistance here.

Come to think of it, a pipeline that feeds the problem text into an LLM to generate a solution and automatically runs it on the input and attempts to submit the solution, doing this N times in parallel, could certainly solve the first few days' problem in 9 seconds.

AI coding assistants ruined the global leaderboard experience. AoC might as well nerf it by discarding the quickest x percent of submissions, or something...
They should check that LLMs can't solve the problems in 9 seconds and come up with appropriate problems. Or just allow AI assistants, they are now as much part of the programmer's toolkit as syntax highlighting or autocomplete or Stack Overflow, and pretending otherwise is not useful.
The first few days are supposed to be beginner-accessible, it's practically impossible to have something beginner accessible but GPT-inaccessible.
Not gonna happen. AoC always starts with beginner level problems. That's why it's so commonly used for learning the basics of new languages.

A problem that wouldn't be immediately solvable by LLMs would either be too advanced or simply too large to be fun.

This is probably where programming as a whole is going. Many of the things that make programming fun for me, like deeply understanding a small but non-trivial problem and finding a good solution, are gonna be performed much faster by LLMs. After all most of what we do has been done before, just in a slightly different content or a different language.

Either LLMs will peak out at the current level and be often useful but very error prone and not-quite-there. Or they'll get better and we'll be just checking their output and designing the general architecture.

That's like going out for a run and taking an electrical scooter around the park instead. The point isn't finishing, the point is doing the activity.
Then why have a leaderboard?
Because someone likes to compete? There are 5k races as well, which people enjoy to do even though vehicles exist. And people would rightfully be upset if they got beaten by someone not running themselves.
And then allow aimbots for counterstrike, stockfish at chess tournaments and Epo on the tour de France. The leader board is intended for people to compete against each other, one could make a separate leaderboard for LLM, kind of similar to the chess AI leaderboards.
> allow aimbots for counterstrike

I'm not played counterstrike in over a decade, so you got me wondering - are there matches where everyone uses aimbots? What does the game look like then? I suppose there's a new mix of strategies evolving, with a higher focus on the macro movement planning?

> are there matches where everyone uses aimbots?

Yes

> What does the game look like then?

I have only observed the games, it requires a lot of hiding.

Most of the time the winning method is to act at the very last second and hope the other player is distracted.

False equivalence. The sole reason for counterstrike and chess to exist is competition. Programming is about solving a problem. If you want to turn programming into a competition you shouldn't take away tools from the programmer.
You’re saying programming isn’t not equivalent to chess here because programming isn’t a competition, but the Advent of Code leaderboard very much is a competition.
It's not that bad. I'm sure there are more LLM'ers in there than the one, but you can tell that the majority of the day 1 leaderboard is made up of people who have historically performed well, even before LLMs were a thing.

Compare https://adventofcode.com/2024/leaderboard/day/1 to e.g. https://fuglede.github.io/aoc-full-leaderboard/

There was also at least one instance of people working together where you would have 15 people from the same company submit solutions at the same time, which can be a bit frustrating but again, not a huge issue.

Okay, I think I have to go ahead and retract my own comment. Day 5 appears to have been sufficiently tricky for humans to do quickly while still easy enough for the LLMs that it is clear that there is a very large amount of cheating going on.
I have a rule in life: no summary statistics without showing the distribution.

Usually this goes for any median which might be in a sneaky bimodal distribution of, say, AI models vs humans. I guess it applies to leaderboards too though.

Potentially the challenge just doesn’t make as much sense anymore? There apparently are „mental calculations” competitions and I’m sure their participants have fun. Yet I can hardly imagine doing arithmetic in ones head is any fun for an average mathematician. The challenge just shifted elsewhere over time.
OpenAI did something similar with their o1 model. Ran a coding problem through o1 thousands or maybe millions of times and then checked if the solution was correct.

I can imagine a great pipeline for performance optimization: 1. have an AI generate millions of tests for your existing code 2. have another AI generate faster code that still makes the tests pass

So I guess all I want for Christmas is a massive compute cluster and infinite OpenAI credits :P

For comparison, here's how long it took in past years:

    2015 - 10:55
    2016 -  7:01
    2017 -  1:16
    2018 -  1:48
    2019 -  1:39
    2020 -  7:11
    2021 -  1:07
    2022 -  0:53
    2023 -  2:24
And this year's second place was 0:54.
Caring about the leaderboards is the problem. Are you (impersonal) seriously doing AoC for clout or something?
I did it without AI last year and planning to do it again, for fun.
True. Leaderboards are and always have been full of cheaters.
The primary reason to not care about AoC leaderboards is that that it penalizes people for being in the wrong time zone. That said, the top 100 or so contributors clearly do care about these things and using an LLM is cheating.

In particular the LLM cheating isn’t just by conjuring a solution: humans don’t get ASCII characters pumped directly into their brain, we have to slowly read problem descriptions with our eyes. It takes humans more than 9 seconds to solve AoC #1 purely because of unavoidable latency.

I wonder how many seconds could be won by the organizers if the challenge included a blant prompt injection breaking the result.
I participate almost every year but I don't care about the leaderboard. The timezone play a crucial role in being able to be ready at the right time, so actually who cares? I prefer to build private leaderboards with my friends and colleagues.
At this point, it just shows that Advent of Code is completely worthless given the ease and accessibility of AI-assisted tools to solve these problems.

RIP Advent of Code.

Why? Solving interesting problems to learn is a worthwhile goal. Why should it matter to you that others are "cheating"?
Because competing against other people is the fun part for some people. Why not allow everyone to use stockfish at chess tournaments?
This is stupid though. Advent of Code Leaderbords were always full of cheaters. At least since 2020 when I first started. If you want competitive programming, AoC is not the place for that.
“For _some_ people” is at odds with “_completely_ worthless”, don’t you think?
To be fair, I read it as "_completely_ worthless for _some_ people"
Without condoning cheating, I am impressed with the automation aspect of it. 9 seconds sounds more or less like the inference time of the LLM, so this must have been automated. Login at midnight + lots of C&P may not have done it.

Perhaps there is a scope for an alternative AoC type competition aimed at AI submissions...

...though of course that would be experimenting to get us all out of work. Hmm.

If real life problems were as easy and defined as AoC problems we might be able to be replaced at some point. I highly doubt you can replace software devs otherwise. Who else is going to take the blame for software issues?
"Write me a snippet that does X" is a step behind "figure out how to log into this page, download the data, write a snippet that gives the right answer to the sample data, then run it on the real thing and submit the output to the text box".
(comment deleted)
As with real life, the speed generally doesn't matter as long as you get a working solution and you find it fun. If you find "copy and paste into an LLM and then copy and paste the answer back out" fun, then I suppose you do you.

I didn't realise it was be timed, which is good because I casually set up a new rig to give future puzzles some kind of rig. I used C# which, although probably more wordy than other solutions, did the job and LINQ made light work of the list operations. Ended up with about 6.5 minutes for each one but most of that was refactoring out of pedantry.

It feels like AI will shape a lot of the submissions for these types of coding “traditions”. But, I guess that’s just the world we live in.
Even before AI I was never fast enough for a respectable global rank, but it's still fun to compare solutions with friends.
I'm actually pleasantly surprised by the results. I like to think that despite problem 1 being easily solvable by LLMs, just about everyone (sans qianxyz) read the FAQ, and decided that they would forego a leaderboard spot for the sake of this coding tradition.

Either that, or there were hundreds of people trying and none were able to get it working despite the basic problem. I like to imagine most people reading the rules and being a good sport.

All the people I know already participate on private boards. AI enshitification will only speed up the process of moving there.
Are we using enshittification for everything we don't like these days? We invented calculators, those really enshittified manual arithmetic puzzles. Private boards for this stuff makes sense anyway, it's the Internet afterall.
Using LLM for this kind of thing is like using cheats or aim assist for online games. So yes, this is prime example of enshifittication.
I think the intent is important. Using LLMs to do well on the public leaderboard is like using cheats/aim assist. But learning how to use LLMs to solve complex puzzles independent of any sense of "competition" is more like when people train neural networks to drive a car in GTA or something - it's not hurting anyone and it can be a real learning experience that leads to other interesting byproducts.

But, yeah, don't use LLMs to try and get 9 second solve times on the public leaderboard, it's not in the spirit of the thing and is more like taking a dictionary to a spelling bee.

enshittification isn't "things become worse" - it's the specific process of how services worsen in 3 stages:

> Here is how platforms die: first, they are good to their users; then they abuse their users to make things better for their business customers; finally, they abuse those business customers to claw back all the value for themselves. Then, they die. I call this enshittification, and it is a seemingly inevitable consequence arising from the combination of the ease of changing how a platform allocates value, combined with the nature of a "two-sided market", where a platform sits between buyers and sellers, hold each hostage to the other, raking off an ever-larger share of the value that passes between them.

Just because that's how it was defined in a blog post doesn't mean that it's the only way to use it
We already have plenty of words for the ancient and generic concept of things-getting-worse, like "ruining".
No, we do not. Calculators are a whole different issue from LLMs, which plagiarize and spoonfeed whole paragraphs of thought.

Enshittification occurs when previously good or excellent things are replaced by mediocre things that are good enough for those susceptible for advertising and group think.

Examples are McDonalds vs. real restaurants, Disney theme parks vs. Paris, the interior of modern cars, search engine decline, software bloat etc.

> those susceptible for advertising and group think.

That's everyone, including you, no matter how edgelordy you post about 'normies' and how you are above that. See how quickly your brain hands you "McDonalds" and "Disney" when you need an example.

Yes you just used the first one that came to mind, the one that everyone would recognise, that's because billions of dollars keep McDonalds first in mind and universally recognised. And even if you make your personality "I wouldn't eat at McDonalds" that money is getting you to propagate the name on HN, just to remind people it exists and keep people talking about it.

Just the shitty things like using LLMs to spoil a fun competition
It also doesn't make any sense for most of the people to compete with the geniuses on the public leader board. It's like signing up for the Olympics as an amateur athlete.
The global leaderboard is so fast that any AI assistance would literally slow them down, here's one of the guys who tends to score highly solving today's puzzle. (https://youtu.be/ym1ae-vBy6g), and on the more complicated days that's even more pronounced because anyone who is even somewhat decent doesn't need to ask chatgpt how to write Dijkstra.

Obviously if you're doing it recreationally you can cheat with AI but then again that's no different than copying a solution from reddit and you're only fooling yourself. I don't see it having an impact.

The thing is that the AI can read a puzzle faster than a human can. If someone put any effort towards an AI-based setup, it would easily beat human competitiors (well, up until the point the puzzles got too difficult for it to solve).
I've always done AoC "properly" but this year I've decided to actually use it as a learning experience for working with LLMs (and I don't get up early so will never sully the leaderboard) and trying some experiments along the way.

I think the strategy for the harder puzzles is to still "do" them yourself (i.e. read the challenge and understand it) but write the solution in English pseudocode and then have an LLM take it from there. Doing this has yielded perfect results (but less than perfect implementations) in several languages for me so far and I've learnt a few interesting things about how they perform and the "tells" that an LLM was involved.

Python looks excruciatingly slow to me. If you want fast I believe you need to think and write in vector languages like kdb+/q. I am not a kdb+ expert by any means and my code can probably use more q primitives, but here was my solution in ~2 minutes:

  i1:("I  I";" ")0: `:1.txt;
  sum {abs last deltas x }each flip asc each i1 / answer 1
  sum {x * sum x = i1[1]}each i1[0] / answer 2
That’s cool, but horribly ugly! What does production kdb+ look like? Is it similarly terse, maybe Perl-ish, or was this purely for speed?

What does each flip asc do?

i1 is Nx2. asc each i1 sorts each N in ascending order. flip transposes to 2xN.
Everything autocompletes in Python.

    from collections import *
    xys = list(map(int, open(0).read().split()))
    xs = xys[::2]
    ys = xys[1::2]
    xs.sort()
    ys.sort()
    print(sum(abs(x-y) for x,y in zip(xs,ys)))
    
    yc = Counter(ys)
    
    print(sum(((yc[x])*x for x in xs)))
this is the least amount of loc I can think of rn

    data = { i+1 : sorted([ x for x in list(map(int, open('input').read().split()))[i::2]]) for i in range(2) }
    total_distance = sum(list(map(lambda x: abs(x[0]-x[1]), zip(data[1], data[2]))))
    print("part 1:", total_distance)
    similarity_score = sum(list(map(lambda x: (x*data[2].count(x))*data[1].count(x), set(data[1]).intersection(data[2]))))
    print("part 2:", similarity_score)
Woohoo, one of the highlights of this time of year. I had to do mine from an eastbound flight over the pacific. This has become a fun tradition not just for me personally but for many friends, colleagues, and fellow HNers. Big props once again to wastl and his helper elves for making this!

I encourage anyone who gets value from this to donate to support it if they can. It is a passion project but nonetheless comes with real costs.

> I encourage anyone who gets value from this to donate to support it if they can. It is a passion project but nonetheless comes with real costs.

With the sheer amount of sponsors and AoC++ users I do believe that this is not quite a small 'passion project' struggling to pay the monthly subscription to a VPS.

That being said, adventofcode is absolutely great and people should support it if they can. But I do think the author is doing quite well with the amount of support he is currently receiving.

Is there a way to override the CSS (on Chromium)? The body font and weight, Source Code Pro is far too thin and far too wide and gives me a headache (and has regularly turned me off AoC). I'd like to change it to `sans-serif`.
On thing you can do is fetch the html and extract the main content to display it in your favorite way, it's been stable for years, and you can use the (stable) session_id cookie, it's how many people approach the challenge.
You can hit the "Reader" button on Firefox (ctrl-alt-r), I think Chrome also has that? Or an extension that does the same thing would probably work.

Bit simpler than writing an override or fetching the HTML.

(comment deleted)
I'd just create a bookmarklet or run JS in devtools: `document.body.style.fontFamily = "sans-serif";` etc
Nice to see that traditions are upheld, such as the unreadable font and colors.
And the timeless tradition of HN commentators cynicism
And the timeless tradition of criticising perfectly valid concerns. Not everyone wants to be a member of the dark mode lobby.
And the timeless tradition of HN commentators contempt
I had to fiddle with the colours in the web inspector to even read the page. So yeah...

Of all the cynical comments I see on HN, this ranks very very low.

Reader mode or "View -> Page Style -> High contrast" in your browser works perfectly fine.
(comment deleted)
Personally I love the esthetic and hope they never change it.
It's a simple webpage. If you don't like it, you can customize the CSS with a few custom rules in your browser.
(comment deleted)
I love AoC. You don't have to care about the AI bots solving it or people waking up earlier than you, just solve it for your own fun. Either because you like the challenges, or to try it in a new language etc.

I like to do them in a functional style in Kotlin as far as possible, as that's different from what I do at work.

Edit: Here's mine from today, with my utils it's not exactly plain kotlin, but part of the fun is building a library of sorts with cool functions https://github.com/Matsemann/algorithm-problems/blob/main/ad...

Nice one, i like your transpose function, as python-numpy user in past years, but kotlin this year, i really missed the transpose function the most for this day one. My code: https://github.com/charelF/AdventOfCode/blob/main/kt/src/y20...
Unzip was nice, will remember that one!

This is also what I like, reading other's solutions and learning new stuff. I browse the subreddit after solving it myself to see all kinds of cool approaches.

yes perl was the original advent of code iirc
I was looking for a puzzle in the first link until I saw the home page: "One article on Raku per day, until Christmas." I vaguely remember these from my Perl days (a decade ago) now.

AoC usually loses my interest around day 6 or so, but a PDL journey for the advent sounds a lot more appealing. Time to dust off my Perl skills and see if I find it as fun today as I did back then.

[flagged]
(comment deleted)
I love AoC, but I hate the timing. December is always the busiest month of the year, so I really almost never find the time for it :(
You don’t have to do it in December. I was still working on last years in March.
(comment deleted)
I've never done AoC but I've done other programming-related challenges before. I come from a non-IT background (mech eng), and I'm currently away for work for the first several days with only their locked-down laptop.

Normally I'd break out Python for this, but given the constraints maybe I should try to see how far I can get through this in Excel. It'd be a fun little challenge :)

My approach here would be to make an index.html file with a script tag and drag it onto whatever browser is available. Then again I have made peace with JavaScript!

(I think you could even use typescript with this method with the on the fly babel transpiler (you just include a script tag) but I haven't tried that.)

You'll lose the benefit of the TypeScript compiler picking up mismatched types if you only use a transpiler.
Interesting, the in-browser one doesn't do type checking? They're actually adding that to JS itself as far as I can tell -- the ability to strip TS types and run it as-is.
I use Excel for the first few as well! I actually find it to be easier than using Python/Javascript, at least early on.
I will try to do it with F# and Gleam this year, but like every year I won’t have time (and brain) to do more than 10/12 days ^^

For the pythonists around here, give F# a try: it can feels very close to scripting and it has a wonderful REPL too :)

How's linux support? :)
If almost 9 years were not enough to make this question seem silly, perhaps DuckDuckGo/Kagi/Perplexity could answer this?
Sure those can answer it. That person is perhaps trying to be social on a social network by inviting comments instead?
This specific question posed in this specific way usually implies a negative interaction. I have seen maybe one exception here so far.

And after providing detailed answers for so many times, I don't think it's worth it.

You guaranteed it would be a negative interaction when you negatively interacted with the post. You're allowed to skip the ones you don't want to reply to.
Perfect, run loads of f# and c# on Linux, and have for years
Works like a charm for me with Ubuntu 24.04/VSCode/Ionide (F# extension) !

For AoC I don't use a real project setup, just a `dayX.fsx` file and I run it like a script with `dotnet fsi dayX.fsx`, et voilà :)

I am doing it in bash. Will see how far I can go!
I've done last two AoCs in F# (well, only the first few days too). For a person without prior functional programming experience, it was fun! Unfortunately I won't have time to participate this year, but if I did, I'd probably chose F# again.
Nice. I've started picking up F# too and am trying AoC with it this year. I'm still early in my functional journey, but I think AoC has been helpful thus far.
I can't explain why but doing AoC is always interesting, and doing LeetCode which is supposed to be similar is always very depressing.

Wishing everyone a fun challenge. This year I will be practicing F# and hope some of you will give it a try too :) https://github.com/neon-sunset/AOC24/blob/master/day1.fsx

That's actually a very important question I think, and sorely neglected by most educators! (and book authors, etc)
AoC would be more stressful if you had to solve a problem in 30 minutes for a highly competitive job.
I had 3 of those 1 hour interviews for a position at Apple, with people watching every move and thinking of ways to break the solution. I don't think I could do it again, no matter what.
The Christmas theme is fun and it’s nice to do one problem per day with a large community.

With leetcode you’re off in the woods by yourself. Stuck on a problem? Here’s a cold write up. Finished a problem? Do another, monkey.

The community is most of the difference. That and the problems aren't very similar to leetcode.
I’m also doing them in F# (again). Hoping to best my past attempts, never gone beyond day 12 before!

I’m never gonna do it fast but I enjoy using fparsec to get the input text in whatever format I need each time, even if writing and debugging the parsers sometimes takes up way too much of my time!

Have you ever tried the LeetCode live competitions? I found those to be really fun with a great community. Just grinding problems in isolation can definitely be depressing.
Think it's because certain topics, such as dynamic programming or graph algorithms, are just not something you can attack from first principles for most mortal people. I certainly wouldn't have invented binary trees. So there is quite a bit of things to read up on (though it should all be covered in an algorithms course).

Then once you do get that context... like LeetCode problems often aren't very inspiring? A lot of the time it's "just apply this technique here".

Whereas in AoC, at least in the first few weeks, it's mostly just, do the task, attack it from first principles.

> You don't need a computer science background to participate - just a little programming knowledge and some problem solving skills will get you pretty far.

The use of “pretty far” gives them a bit of an out, but I think this statement is a little disingenuous. Last year, at least, a bunch of the problems needed fairly sophisticated algorithms to find the solution in a reasonable amount of time.

To me, a little programming knowledge is what somebody who is six weeks into their introduction to programming class has. They know variables, loops, lists, and maybe associative arrays.

Anecdote to support your comment: The Chinese Remainder Theorem has featured in Advent of Code at least twice IIRC. Not an algorithm the average programmer (average is a very fuzzy term, yeah) would know.
> The Chinese Remainder Theorem has featured in Advent of Code at least twice IIRC

Fortunately it's never been needed. Every time it's come up the problem has been solvable with high school algebra level math skills (you need to know what the lcm is and that's covered in middle school in many places). If you knew the CRT you could jump straight to a solution, but a solution was easily derived using algebra and a couple loops.

(comment deleted)
Got some specific references for the days that was required?

I think a lot of people are so focused on "optimal" solutions they fail out or burn out quickly, ignoring the ugly "just loop a bunch of things" option.

I'm by far an expert on AoC, but the number of people I see every year on day 2 or 3 saying "IT'S TOO MUCH" because they were trying to implement some crazy algorithm when basic array operations and for loops would solve it...

I flunked out of high school. I don't even properly understand algebra, never mind any sort of complex math. I have no CS degree. I've completed most of it in some gross PHP that completed before next year on a single core in an old laptop.

If "knowledge of obscure algorithms" is a requirement either I'm a once in a generation genius or... it's not a requirement.

"Participate" doesn't mean "win". You can look things up as well. I haven't done a ton of AoC, but the harder ones from it I've seen were not very hard to search/research for the correct algorithm (even avoiding "what's the answer for day X" searches).
AoC doesn't require any particular algorithmic knowledge to solve its problems. Sometimes knowing algorithms is useful to quickly write your solution, but IME it's never a requirement. Unlike leetcode-style challenges, AoC tasks usually don't even try to punish you for solutions that are specific to your particular input. You can get some stars with just pen and paper.

It's more like a set of logic puzzles. Programming and algorithms are only incidental.

Other challenges (in advent and not in advent) like advent of code:

https://github.com/NoelJacob/advent-and-other-calandars Compiled by myself.

Not a challenge, but it may be of interest anyway - Sergey Tihon's F# Advent Calendar: https://sergeytihon.com/2024/10/26/f-advent-calendar-in-engl...

I think there's a few of these for different languages/tech. I think they may be good for HN'ers seeking some kind of little daily advent-y fix without the potential emotional/mental investment of AoC.

That’s an impressively broken website on mobile. Really, I haven’t seen a site I wasn’t able to scroll horizontally before.
This is great, thanks! I usually do AoC to learn a new programming language but there's no more language I care to learn right now.
Do you want to add Genuary to your list? A month of daily prompts to get you producing some generative / creative coding art. Starts Jan 1. Website here: https://genuary.art/

I've promised myself that one year I will move beyond the first seven prompts ... who knew creativity could be so taxing?

Last year I got stuck on Day 12 for a full week, and thinking about how to solve it consumed my every waking moment. I think this year, I'm going to be kind to myself and not participate so I can really enjoy the winter break from work.
Sounds sensible. It's important to set boundaries, and enjoy time off.

For me Advent of Code is a slippery slope. The difficulty ramps up so at first it's easy, then it's rewardingly difficult. But then before I know it, it takes wayyyyy too much time. The danger is being emotionally invested by then.

There's a graph here of the "hardness" of each day/task, based on how long the 100th place on the leaderboard used. https://aoc.xhyrom.dev/

So it's not linear, and also based on your own knowledge. So perfectly fine to skip some days and still it's possible to solve some of the next ones!

Cool, it would be nice if that one aligned the days which were on weekends, as those tend to have harder problems.
If I understand correctly, and I'm not sure if that graph proves that, they try to put longer puzzles on weekends.
Right, Eric Wastl addresses exactly this in his talk. He considers weekends and burnout in the pacing of the event. I think this is the right video: https://youtu.be/bS9882S0ZHs
> So perfectly fine to skip some days and still it's possible to solve some of the next ones!

You try telling that to my brain. That guy doesn’t listen to me.

This is why I usually do the simpler ones and then stop... Otherwise, I just can’t skip, it’s stronger than me.
Ugh, I hate log scales used arbirarily, every silicon valley nerd things it makes them cool like their EE profs teaching actual science or Ray Kurzweil singularity whatever nonsense.
Ray Kurzweil is indeed full of crap (I have a specific bone to pick with his intentional mis-use of life expectancy among other things), but what makes you think in this case the use of log is arbitrary? Did you look at the data with a linear axis? I just tried it, and the vertical space is dominated by 4 or 5 outliers, and on top of that you can’t see the trend as well when it’s linear and all the data is smooshed at the bottom. Log plots are great when your values span many orders of magnitude. That’s true in this case, and the log plot both uses less vertical space, which is nice, and it more clearly shows the trend and wastes less empty space on the small minority of outliers.
There are some "filter" days for sure, usually those are when the solution needs a major leap in your approach such as concurrency, dynamic programming, or geometry equations.
It's usually not concurrency FWIW, it's almost always algorithmic in nature. On a modern machine, even highly concurrent* code would only execute 10-20x as fast and you could just wait a bit.

One common AoC trick is that you can brute-force part one (e.g. O(n^2) complexity or worse), but part two scales up `n` to make that intractable.

*ignore my sloppy conflating of concurrency and parallelism

I agree with you. I don't think either concurrency or parallelism have ever been necessary. In 2019 with Intcode, it was the simplest approach (use multiple threads, one per VM) for a couple days, but it was never actually necessary. You could do the same thing with purely sequential code, but you had to juggle the state of multiple running systems yourself then. Threads were much easier (or coroutines, go routines, processes, etc.; some concurrency system).

And by design, every problem is solvable on decade old computers in a reasonable amount of time (seconds) so parallelism is great if you're looking to minimize the runtime, but it's never necessary.

I very much enjoy the cat and mouse game of assumptions regarding part 2, it always makes me happy when the second part is just a simple adaptation of the existing solution.
For those just glancing at the chart do note the scale is logarithmic, so the difficulty increases exponentially.
Either the problems are getting easier each year, or perhaps there are just more people participating which drives down the 100th-place times.
I usually make it Monday 18 or 19 and then I loose the will as the time taken is excessive, and obsessing about it is not good. I've finished a 5 years, but all after the fact. Some I am not sure I'll ever finish....
Ah yeah I've been there! Having done it a few years now, I've found that the approach that works for me is: if it starts looking like I'll be stuck on one for more than a few hours, I'll skip it and move on. Otherwise I'll accumulate an insurmountable backlog that becomes more of a depressing chore to think about, than a fun little christmas tradition. I'd rather have a mostly-complete set of problems by the end of the year that I can come back and clean up when I feel like it.

That said, if you'd have a better holiday season by just stepping back from the computer and relaxing then that sounds great too. Either way - enjoy!

My main complaint the last time I did this (2022) was the havoc it wreaked on my sleep schedule. Advent of Code is not kind to East Coast participants.

Every year except for one has been kind of the same pattern for me:

Day 1: this year, I'm just going to solve the problems. No futzing around.

Day 3: but it would be kind of neat to turn the solutions into a reusable AoC library. Just something minimal.

Day 5: and I should really add a CLI harness for retrieving the problems and parsing the input files.

Day 6: and testing of course.

Day 7: maybe I'll skip today's problem (just for today) and keep improving the framework.

Day 358: oh neat, Advent of Code is coming up.

I'm in CET so time-wise it can be ok - problems open at 6am meaning if I get up I have about an hour around before I need to walk my walk my dog and get ready for work. But switching on at that time is really hard, the amount of stupid off-by-one errors, or referring to since-renamed-but-still-present functions in my Jupyter Notebook is not even funny.

But I luckily managed to avoid the "reusable AoC library" problem around 2019 when a week beforehand I wrote down the sort of functions I wanted to have at my disposal (usually things around representing 2D/3D grids of unknown size and pathfinding/debugging therein, but a few other bits and pieces) and made a simple library that I will sometimes add things to after I'm done with the problem for the day.

I was tempted to some functions (similar to those your CLI harness provided) for retrieving test data and submitting answers but I managed to stop myself short of that! But I am sure you're far from the only one to end up down that road.

What if you don't get up?
If it's a work day and I don't wake up on time, I'll pick away at it over the course of the day - usually I'll get a chance to think about it on my tram ride to work and complete it at lunchtime

If it's a weekend I'll just do it at my leisure at some point during the day when I have some time - maybe head to a nice cafe or something.

I'm nowhere near the top 100 - closest has been iirc top 200 a few years back - so it's not like I need to start at 6am.

I have trouble fitting this kind of thing in consistently. It's hard with work, chores, family, and then motivation to code after coding at work.
I'm in CET too, and 6:00 is not an hour where I’m awake, and if I were, my brain functions would definitely not be at a level where I would be capable of coding.

Midnight would be much more acceptable.

I think you'd be surprised - you'll definitely be capable of coding at that hour. But like me you'd just also be quite capable of making daft mistakes :D
Stay out of my head!
I will probably solve the first 7 puzzles like every year and then just stop.
This is my experience. After the first week I develop an intense hatred of all things Elf and start swearing at my laptop. At which point I give up to stop my mental health deteriorating any further.
Hahaha...I love this comment. I have just been stuck for a week doing edge puzzles and backstepping recursion, keeping myself awake aye night because it bothered me I couldn't "just" solve it.
Likewise. I did it one year in college and it became a life-consuming thing almost immediately. Not AoC's fault - part of it was depression, part of it was the Minnesota winter. Now that I have a full-time job and a wife, I'm trying to be more careful with those things that I know will suck me in.
All things in moderation! Now if I can just make it through the winter without installing the new Factorio DLC...
this comment actually prompted me to finally download and install the factorio demo, been hearing so many things about how it takes over lives! :)
So, you want it to take over your life?
No, I want it to be great, and if it takes over lives, then surely it must be great.
It really is such a great game! I got the base game, beat it a few times, then my partner and I played a few mods, currently in an Angels+Bobs playthrough. So much replay value
I've been playing half an hour each morning before the rest of the family wakes up. Just finally made it to the volcano world
It ate my life for a few years in a row, I even managed to finish on Christmas eve twice. Now I don't even look, it turns from fun to stress rather quickly.
Only year I ever completed it it took eight months.

I’m not seeing my name on a leaderboard any time soon.

Oh yeah, me neither. The competition is far too intense. What takes me hours takes the competitors minutes.
I actually made somewhat of an effort this time, made sure I was awake in good coding shape when the problem was released. Had a scaffold set up for running the code based on previous years. And I'm a pretty decent all-round coder, should be by now.

Ended up at around spot 6500.

Boggles my mind to even imagine what it would take.

You can see videos of what it takes; Jonathan Paulson makes the leaderboard often with Python and puts videos of him doing it on YouTube; he made positions 25 and 40 on day 1 this year and here is his video: https://www.youtube.com/watch?v=ym1ae-vBy6g
Nice.

I can move that fast, faster even, when I know exactly where I'm going.

I imagine if I was doing this kind of problem solving all day every day it would be possible.

I re-read the intro and the fact it mentions leetcode and the like was enough for me to decide that it's an ultimately pointless endeavour for me.

I have no interest at all in competitive programming or maths; I spend 40+ hours a week doing programming for work, I want games and challenges that pull me away from that so I continue to have a life outside of my job.

For what it's worth, I hate leetcode with a burning passion, have no real interest in math, and yet I personally find Advent of Code quite fun and enjoyable.
I have found AoC fun, but on some of the later days time constraints make it a little stressful (full time job + kids constrain my time).

I've done it (and completed it) the last five years. I used it to try out a few languages (Haskell, Idris, Lean) and did it in python one year I was feeling lazy. I've got a project going now, and I probably should do that instead.

However, that project is a programming language, so this is a way to test practicality. But solving problems and fixing shortcomings in the underlying language at the same time may be a bit too much. (It's a dependent typed language, so there is a lot of subtlety to deal with.)

Same, I've been coding for 40 years and I still learn plenty every year.
I find it useful for trying new languages. The first 10 days usually start very easily and progress quite gradually. The 2nd half definitely gets more brutal, but if you do have the self-control, you can stop whenever it stops being productive.
I love it for these meta-type use cases that aren’t necessarily about solving the puzzles.

For instance I’m using it this year to dial in new neovim configs. Last year was to get comfortable with a split keyboard.

How about something creative that is at the same time relaxing?

Some time ago I started creating mods for the game stardew valley. It still involves some programming but mainly drawing, creating animations and composing music! It's an absolute blast and so relaxing (like the game itself).

I think by now I could even start working on my own game but I don't yet have a desire to.

Not OP, but that’s really neat. What’s your process for that? What IDE for the coding? Is C# required? What software for the art?
I started with something called ContentPatcher. It let's you patch game assets and other stuff (including some logic) using a json based DSL.

For more complex things C# is needed as Stardew Valley is made with XNA/MonoGame. There is a NuGet package to set it up which even includes hot reloading of the mod into the running game: https://www.nuget.org/packages/Pathoschild.Stardew.ModBuildC...

I use NeoVim but you can use any editor. It was a bit of a pain to get dotnet going on arch linux but I got it working after some tinkering.

To get started, one can install SMAPI, then unpack the game assets. Then, you can open game maps and assets in the Tiled level editor. I also use Aseprite to make the pixel art tilesets for the maps (LibreSprite would also work). I use a mix of my own tiles and tiles from the game itself for my maps. Music and sound can also be added or patched with ContentPatcher. I make all sound related stuff with Ableton Live. I haven't done much with C# yet but SMAPI provides a pretty nice API so it should be pleasant to use.

Not the OP but as someone with the same mindset as them:

Sounds very fulfilling, but I explicitly want to stay as far away from tech as possible outside of working hours. I'd much rather draw and compose music outside of any tech environment.

Plus, creative hobbies are an amazing way to connect with people, it's half the reason I like them. Tech hobbies are going to make me connect with tech people which isn't what I want: I meet enough tech people at work, I'd end up talking about tech (languages, frameworks, software, AI...) outside of work which have no interest in, and I don't really relate to tech people anyway (as a sweeping statement that obviously isn't an absolute)

I go in to this not caring how fast I do it, or how far behind I get. It's just an opportunity to learn something and challenge myself a little bit.

At best, I tend to set myself an upper limit for runtime.

I have enough fun side project ideas that I want to do. Ones which will also be helpful for me once I’m done with them.
I have enough side projects on the back burner as it is. I even picked up a data processing one over thanksgiving.
An offline version could be an "Exit" advent calendar game. Now that advent has started, you might find them discounted at a local board game shop.

Note it's a single-use game.

https://boardgamegeek.com/geeksearch.php?action=search&objec...

(I don't see any reference to leetcode, but people can approach Advent of Code however they like. I'm certainly not waking up at 5:50 to race for a solution.)

Solving the puzzles in a REPL in a dynamic language brings a lot of joy to AOC.

My daily grind is like carefully scaffolding and repainting a 50 storey office building made of typed, modular, spaghetti couples Python ML code.

AOC in ipython, by comparison, is like doodling pictures with a brush pen!

It is very enjoyable and also why leetcode is a little silly for interviews: convince me you can I want to know a candidate can flawlessly paint several hundred square feet of wall, not doodle a cat cartoon.

(Or, away from the analogy, the software equivalents. Can you safely progress business goals as a member of a team on a legacy codebase that’s partly evolving on the cutting edge and also partly rotting on the trailing edge? I don’t care if you can build a naive implementation of our trading system… sorry I mean an Elephant Auction… in 90 minutes!)

The don't do it. Thanks for the update though
Advent of Code is traditionally parsing heavy and very light on actual mathematics. It’s not very leetcody.

If you have never tried it you should definitely give it a go. It’s quite enjoyable at a moderate dosage.

I just do the puzzles until it stops being fun. For me that's usually around day 14.
Goes up and down for me, some I enjoy a lot, some are mostly painful details to get right.
We run a private board for Advent of Code for the Carolina Code Conference. Eligibility for prizes starts after earning only 10 of 50 possible stars precisely for this reason.
Oh cool. I live in WNC and had just missed your last conference in August. Is it possible to join multiple private boards? I usually do one with my coworkers as well
You can only “own” one board, but you can join many.
That's awesome. We do the exact same thing for prize eligibility on my work leaderboard. The whole point is for it to be fun and challenging. No need to grind to the end unless you want to.
One reason I didn't enjoy it was that I felt the days don't build on each other well. So you get little code reuse. It was continually changing requirements, so it was especially like work.
In 2019 he built up about 12 challenges using a VM, for Intcode, you had to construct. It was poorly received because without a working version (developed over the first few Intcode challenges), you couldn't solve the rest of them. He hasn't done anything like that since, though I thought it was probably the more interesting series of challenges.

The problem with continuity across days is that the later days can be blocked by the earlier ones, as they were in 2019. That partly defeats the purpose (or structure) of the challenge, where you can mostly pick any day and try it without regard to earlier days or prior years.

I agree. Intcode was fun, but completely destroyed the promise of skipping a day and still having fun with later puzzles. I didn't come to enjoy it until much later.
I agree that it wasn't completely well-received, and I think this is a real shame. The stated goal of Advent of Code was always to make better programmers. Extending, maintaining, and testing large systems is an important part of real-world engineering efforts.

I thought the IntCode thing was great and I hope to see something like that again this year.

People are skipping days? I usually drop out when I'm stuck on some day. 2019 was my favorite.
Most years I've skipped a couple days and revisit them later. Usually just because I give myself 1-2 hours limit to avoid staying up too late working on them, and unless it's the weekend I don't always have time during the next day to wrap them up. No reason to stop just because of a single blocker.
I can understand that. I think it just points to that the challenge is not for me. It also comes at a time when I desperately want a break or to work on my own projects, software or otherwise.
There's a lot of potential code reuse between years; whether that's good or bad is up to you, I think. (I would personally prefer if my Chinese remainder theorem solving function got less use, but it seems to be called for every year or two.)
I got stuck on the graph-cut puzzle for FOUR MONTHS. I had to write a force-directed graphing engine to find the longest three edges to cut.

After I solved it I looked at other people's solutions and they used Meta's proposition solver in about 10 lines. Seemed like a massive cheat to me.

Oh man, this is my best memory of last year's AoC. After uselessly noodling for a while, I used Graphviz to draw the graph to an SVG file. It drew two messy balls of yarn neatly connected by three edges.

My script still says "TODO: find a real solution". Good times.

I have a self-imposed goal of not using third-party libraries for any of the solve logic. It feels more satisfying to do it myself, even if it takes longer.
What solver are you referring to? I've used z3 and OR-tools, but I find it so difficult to model problems in either one that I seldom get good usage of either one.
Like Minecraft, everybody should play it however they want, it's just a game.

Which one was the "graph-cut puzzle" ? I've had a few where I couldn't do them on the day, either I was busy or I found them harder than usual or sometimes both.

It looks like in 2023 I took until almost New Year's Eve to finish, but until like the 21st of December I was fine, I got thrown off by travel and other commitments in the last few days as they got more difficult.

This was the day 25 problem: given a graph of ~1600 nodes and ~3500 edges, find the 3 edges that if deleted divide the graph into 2 components. I looked over some of the solutions and it surprised me how few used the simplest method: for each edge with endpoints u, v in the graph, delete it and then find another path P1 between u and v. Then, for each edge e1 in P1, delete it and then find another path P2 between u and v. Then, for each edge e2 in P2, delete it and then try to find another path between u and v. If there is no path, (u, v), e1, e2 is your cut-set. Otherwise, add e2 back and try the next edge in P2. When you've exhausted P2, add e1 back and try the next edge in P1. When you've exhausted P1, add (u, v) back and try the next edge in the graph. It's 3-6 loops deep depending on how you count, but it works. My python implementation completes in under 2 minutes, but it varies because it appears the standard python data structures have some nondeterminism, and I may have had a lucky draw with my puzzle input.
What's so hard about Day 12? It's just

    +/'{x:".",x;H:(-1+;1+i-)@'+|\m*i:!#m:x=\:"#."
     R:(x=x)({[h;d;x;y;z](z#0),+\(((-z)_~"#"=x)&z_d>z)*(*y),(-z+1)_y-0^y h}. H)[x]/y
     (*|R)-R@*|0,&1_*+m}.''1({("?"/:5#,x;,/5#,y)}.')\@[;1;.:]'" "\:'0:`:i/12.txt
This is what programming languages looked like to me before I learned programming
Any idea how close that is to valid J code?
My limited understanding is that K and J are very different, despite both being in the same language family. I found K a lot easier to grasp when I was playing with both languages years ago.
I'm doing this year in K2 (after a long hiatus from K). Is there a K4/5 binary? ATW gave me a K2 binary, but I miss some of the K4 and later functionality):

https://github.com/jnordwick/aok2024

I don't know if there's a specific k4 binary but you can run k4 through the q binary.
The year I did it I got lucky and solved them all within a reasonable amount of time until there was one that suddenly involved a lot of nontrivial linear algebra and I immediately spotted that this wouldn't be fun and noped out. Noticed the number of people solving dropped off a cliff on that day.

I think as nerds we need to be quite careful not to get too drawn into this kind of thing. Sometimes it's like a superpower, but other times it just pointlessly consumes your life. Kinda makes me think of gambling addiction: "when the fun stops, you stop".

You can also set a time rule. For me it's 45min, if it takes longer to solve it, I an allowed to quit.

It's totally worth it, though, especially for the first week, when you look up how other people solved the thing you just solved. I always learned (or re-learned) something from that. IMHO there's not that much value in looking up solutions before you solved it yourself, though.

I just have them lingering in the back of my brain the whole year. I solved the last one from last year a month ago. This is much nicer than sudokus or whatever: I sometimes dream about them and I keep finding better (in my mind) solutions for ones from years ago. It's lovely when you sit at another dumb crap meeting/standup so you have something to do in your head.
> I can really enjoy the winter break from work

What line of work are you in that you can take a winter break, and furthermore, that you can actually not work during that break? I'm envious...

I've always wanted to do AoC but on top of work it is too much.

I get the week between Christmas and New Year's off and then I take a bunch of my PTO in December. It's not an official break or anything.
Lots of people (in tech at least) take time on top of mandatory vacation that can result in like 2 weeks of time.
Developer here. I'm off from 13 Dec to 6 Jan this year.

PRevious years I've managed basically the entire month of December.

I always have holiday days left over at the end of the year to take.

Heh, I just checked. That's where I got stuck last year, too. I solved the first half.
I would love it if the first star of the day was required, but the second was a bonus. I love Advent of Code, but I don't have the time to get 50 stars.
No stars are required at all. You can also skip some days if you don't want to do them. Or only to the first stars. However you like. First/silver stars will also increase your score in the leader boards.
I think you need all stars to do the final puzzle.
That might be true, I've only completed it once a few years ago. But if you don't want to the more complicated parts, then you want to skip the last one for sure.
I might be mistaken but I believe the final day has only one puzzle, but the 50th star (a.k.a., the second star of December 25th) is given for having solved everything else. I don't think any puzzles are "locked".
You're right. The second star is a freebie for completing the rest.
Same. Especially when it gets really hard later on. Despite studying CS, I still struggle with it.
[flagged]
(comment deleted)
The tiny thin gray font on black background is impossible to read on a mobile device :(
On iOS you can switch to Reader view, and I imagine Android has something similar.
Yes on Android it's already readable in Firefox, but that may be due to ad-blocking plugin. Even so, Firefox reader mode makes it even better.
I tried that, but it broke all navigation links (including to the actual exercises).
Color aside they also ignore a number of solutions for font resizing that follow the users accessibility settings. I can think of at least three easy ways to do this with html/css alone, and yet hear we are; a site that is unreadable to me.

I love what Advent of Code does, but when your site is all text, there's just no excuse to not let the user resize it by default.

AoC day one challenge… make website responsive
It is terrible for me on my desktop too :(
Am I alone in thinking that measuring time to get answer is the worst possible metric? I have not participated because of that (yet).

If there is a community for those who use other rules to compare actual solutions instead of answers I would be interested to hear about it.

I am coming from low level C++ gamedev side so I understand that most people here use different tools to solve different problems.

I think most people don't participate for the competition. I did it several times to increase my coding skills, have fun or get more practice in a new programming language.
It is normal for coding to seek feedback from others to your solution. Even if it is automated. Looking at 'competing' solutions after you spent time on yours can teach how others think. Improving code after you learned new facts is huge part of coding fun at least for me. People mentioned private leaderboards in the topic few times. I just don't think time to submit an answer is relevant.
Why do you care about the time so much then? Just ignore it :D
Can you propose other metrics that don't involve executing stuff in a whole lot of languages? The point is to let people work in whatever they want, as only the solution matters. If only the solution matters I don't really see other options beyond time.
Here's a website that appears to be about competing on the performance of each solution: https://codspeed.io/advent
>Participants have 36 hours

Looks like it is for young people who have dedicated time for it everyday.

Personally I would like to do anything like this with no time limit and probably no monetary prizes. I think the only value of those puzzles is to fire up rarely used neurons that hopefully are still there after another year of shipping corporate products xD. I might appreciate fresh point of view from young people and new programming languages though.

Because only young people can make time for things.

There are plenty of professionals with jobs and families making time for AOC because they enjoy it. Doing the problems at the same time as everyone else is a VERY different experience from doing them whenever you'd like.

If you don't want to make the time for it, power to you. I'd recommend most people to drop off after the first 10ish days. But don't delude yourself by ascribing this as the domain of "young people" or those without responsibilities. You're making a decision. Own it.

I appreciate your perspective and it is correct. I should have phrased it differently.

Imho: I worked with code that has long history for my entire career. If the goal is to look at some objective quality of solution then I do not believe in time limits. The longer I work the more things getting patches/updates/remasters and value of better code goes up and value of arriving at any kind of solution overnight goes down.

For software that's meant to be maintained for long periods, especially by others, I agree with you.

The thing about AOC is that it's really less about the code that you generate, and more about the process of solving the problem. The challenge is really what you make of it. Some people will golf it, some will go for speed, other for performance, etc.

That's why it's so different to solve the problems in "real time". There's a huge community of people solving the same problem that you can interact with and bounce ideas off of. Even just a few days after the problem is released, most of that active discussion has dried up, so you can no longer participate in that discourse.

So, again, I don't think there's anything wrong at all with what you're saying, but there are other elements to consider beyond maintainable code and pristine solutions.

> Doing the problems at the same time as everyone else is a VERY different experience from doing them whenever you'd like.

I agree and I happen to think the experience of doing it later than everybody else is significantly better. If I search for “AoC 2024 day 12 hint”, I’ll get better results on Jan 12 than Dec 12.

After trying to turn day 4 part 2 as example to my colleagues I came back to check the site. Day 1 winner seems like what I would have expected so thanks for the link!

Sry, can't upvote because I mostly read HN not logged in so I still can't upvote. If there were some other performance oriented forums either on reddit or somewhere I seem to be too lazy to find them anyway.

The vast majority of people are doing it for fun or learning purposes and not to compete on the leaderboard, and it wouldn't quite be fair to compare much else in a competitive setting but time of completion and correctness, since you'd be at a disadvantage just by language choice in many other metrics. Unless you are someone with experience competing in competitive programming you almost certainly won't make the leaderboard anyway.

If your goal is to compare solutions, lots of that happens on the subreddit for it where people post solutions in their language of choice on the daily threads.

I just do it for fun. When I was younger I'd actually do them at release (11pm in my timezone), now I don't even bother and just used them as sort of a brain teaser to start my days and compare with coworkers who also do it, a lot of us in different languages.

It could be interesting to find the shortest solution. But the site is not set up for verifying solutions in various languages.
I wouldn’t use an AI to solve the problems, but I wonder if an AI could give good feedback on a solution I cook up?
That's what I've been doing with some older AOC puzzles. I solve it, then paste my solution into Claude and ask for tips on making it more idiomatic. It's been pretty nice so far. I learned about Haskell Arrows which I would probably have never come across otherwise.
That's like saying you don't want to go for a run, because professional marathon runners are so focused on time
I also don't like it, last year we had a private leaderboard at work and I realized being crazy enough to wake up at 5:50 every and solve at least part 1 would give me an edge. But the "wake up at 5:50" part is what I enjoyed the least.

However, there are other ways to rank yourself against others. You can order your private leaderboard by number of stars, or make your own leaderboard using their APIs.

> If there is a community for those who use other rules to compare actual solutions instead of answers I would be interested to hear about it.

Generally you have the main community on reddit (memes, questions, daily thread for sharing solutions), then the language specific subreddits or hosted forums where you will see solutions discussed and shared, plus a couple of new users asking questions.

Also, within the daily main community thread you will see the niche sub community of people posting their code-golfing attempts.

I try to get it done within a day, so they don't back up, but I've never tried to compete. I am PST which opens at 9PM. I try to get through part 1 then, so I can sleep on part 2.

The subreddit /r/adventofcode contains discussions of solutions with lots of different skill levels.

I've done AoC for five years to learn new languages and try solve all of them myself during the month of December. (Dunno if I'll run the whole thing this year - I have another project.) Others try to get on the leaderboard, and some will implement solutions that they've seen sketched on reddit.

Last year a few people used Z3 for one of the problems, and I went back and tried that to get some experience with Z3. And I've occasionally gone back and tried another approach or new trick that I saw on the subreddit. (In the years that I've used Lean, I've sometimes gone back and added proofs for termination or array indices, too.)

One of the things I look forward to. It is a lot of fun.
Going to use it to learn a bit of Ada. I've always been curious about it. It's not a popular language, and it has some serious documentation problems. Sure, there are guides for "hello, world" and other basics, but how to use a generic integer vector or even how to read lines with two numbers from stdin or a file? That was a bit of a puzzle. I saw a solution that allocates an array of 99999 elements, just to track the number of occurrences of each number in the input.

Ada took me somewhere between 90-120 minutes, whereas I had the first problem done in JavaScript in about 30s-60s, just for verification.

Ada.Integer_Text_IO with Get will happily read across all whitespace, including new lines, to find the next integer. This is true for most (all?) instances of Get, though that may not always be what you want.

  with Ada.Integer_Text_IO;
  use Ada.Integer_Text_IO;

  procedure main is
    Left : Integer;
    Right : Integer;
  begin
    Get(Left);
    Get(Right);
    Put(Left);
    Put(Right);
  end main;
If you give it any of these pairs it'll work as expected, put it in a loop and you'll get all of them:

  1 2
  3      4
  5
       6
Sometimes thinking about lines is a red herring in AoC, the lines often don't matter, only getting each value into the appropriate collection (a pair of vectors in this case since you don't know the size). For the counts, you can use a hashed map, they're built into the standard library. If you learn to use them now that'll help you out in later days, they're a commonly used collection (for me) in these challenges.
I know that now, even though some of the details remain fuzzy (Get_Line reads 100 characters?), but it's just that the documentation is a big pile of facts with very little to guide you towards the right function/type. And then to get it to use in the rest of the code. And of course, many 'modern' helpers are simply not available, so that too takes a bit of time to find out. But that's learning.
It stops at 100 or the length of the supplied string or the end of the line, whichever is shorter. You can also use unbounded strings which allows you to skip specifying the size for the output.

  with Ada.Strings.Unbounded.Text_IO;
  use Ada.Strings.Unbounded.Text_IO;

  with Ada.Strings.Unbounded;
  use Ada.Strings.Unbounded;

  procedure main is
    Line: Unbounded_String;
  begin
    Line := Get_Line;
    Put_Line(Line);
  end main;
https://learn.adacore.com - good source of tutorials, unfortunately a lot of the better learning materials beyond this are books, not online tutorials.
Yup. Advent of Code is a fun, yearly alternative to LeetCode with a Christmas theme, and it's approachable for novice developers.
The first day problem is trivial and also solved in a single attempt by o1-preview.

It would be nice if they actually proposed interesting problems and of course checked that LLMs can't solve them.

This is already answered right on the about page[0]. AoC is meant to be an educational experience, feeding it directly into a LLM isn't that.

> The leaderboards are for human competitors; if you want to compare the speed of your AI solver with others, please do so elsewhere. (If you want to use AI to help you solve puzzles, I can't really stop you, but I feel like it's harder to get better at programming if you ask an AI to do the programming for you.)

[0] https://adventofcode.com/2024/about

Using an AI to solve AoC is like taking an art class and complaining that the still life exercises aren’t very interesting because your camera can capture the image quickly.