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Advent of Code 2025

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Re: Advent of Code 2025

#361

Post by alexfoo »

thedavibob wrote: post #357
eshse wrote: post #292

Earlier quoted context omitted.

I live in Sweden nowadays (UTC+1) and it starts at 6am so last year I woke up at 5:30, grabbed a coffee, and gave it a go. Got nowhere near the leaderboard times so gave up after four days!

Yes: I'd argue that the timings actually work/worked better for Western Europe than the USA, I personally preferred doing the puzzle at 5am (UK) than the midnight equivalent, as I could finish before work (on a good day). Nearly scratched a decent ranking once only, top 300 or so.

Either Russia (8am) or West Coast US (9pm) would be my preferred options.

Sadly it's 5am for me as I'm in the UK.

In 8 years I can say I've never once tried to be awake at 5am in order to do the puzzle. The one time I happened to still be awake at 5am during AoC I was quite spectacularly drunk so looking at AoC would have been utterly pointless.

Anything before 6.45am and I'm hopefully asleep. 7am isn't great as 7am-8am I'm usually trying to get my kid up, fed and out the door to go to school. Weekends are for not waking up at 7am if I don't need to.

9am or later and it messes with the working day too much.

Looking back at my submission times from 2017 onwards (I only found AoC in 2017 so did 2015/2016 retrospectively) I've only got two submissions under 02:xx:xx (e.g. 7am for me). Both were around 6.42am so I guess I was up a bit earlier that day (6.30am) and was waiting for my kid to wake up and managed to get part 1 done quickly.

My usual plan was to get my kid out of the door sometime between 7.30am and 8am and then work on AoC until I started work around 9am. If I hadn't finished it then I'd get a bit more time during my lunch hour and, if still not finished, find some time in the evening after work and family time.

Out of the 400 submissions from 2017-2024 inclusive I've only got 20 that are marked as ">24h" and many of these were days where I was out for the entire day with my wife/kid so I didn't get to even look at the problem until the next day. Only 4 of them are where I submitted part 1 within 24h but part 2 slipped beyond 24h.

Enormous understatement: I were unencumbered by wife/kids then my life would be quite a bit different.

Re: Advent of Code 2025

#362

Post by queuebert »

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).

My favorite non-mainstream language for competitions like this and Project Euler is Julia. The startup time is not a factor, and the ability to use UTF-8 symbols as variables makes the code more mathematical.

Re: Advent of Code 2025

#363

Post by queuebert »

TiredOfLife wrote: post #298
alexfoo wrote: post #227

Earlier quoted context omitted.

Got to agree. I'm even surprised at just how little progress many of my friends and ex-colleagues over the years make given that they hold down reasonable developer jobs.

Because like 80% of AoC problems require deep Computer science background and deeply specific algorithms almost nobody is using in their day to day work.

But what about all those LeetCode interviews? /s

Re: Advent of Code 2025

#364

Post by ryandv »

saberience wrote: post #349
ryandv wrote: post #249

Earlier quoted context omitted.

They... sort of are though? A year or two ago I just waited until the very last problem, which was min-cut. Anybody with a computer science education who has seen the prompt Proof. before should be able to tackle this one with some effort, guidance, and/or sufficient time. There are algorithms that don't even require all the high-falutin graph theory. I don't mean to say my solution was good, nor was it performant in…

"Anybody with a computer science education who has seen the prompt Proof. before should be able to tackle this one with some effort, guidance, and/or sufficient time." I have a computer science education and I have no idea what you're talking about. The prompt "Proof." ? Most people who study Comp Sci never use any of what they learned ever again, and most will have forgotten most of what they learned within one or t…

Holy fuck. I should just grow coconuts or something in the remote Philippines.

> Most software engineers never use any comp sci theory at all, but especially not graph theory or shit like Dijkstras algorithms, DFS, BFS etc.

But we are talking about Advent of Code here, which is a set of fairly contrived, theoretical, in vitro learning problems that you don't really see in the real software engineering world either.

> The prompt "Proof." ?

See this paper on the Stoer-Wagner min-cut algorithm from graph theory, for the last problem in a previous year's Advent of Code: https://www.cs.dartmouth.edu/~ac/Teach/CS105-Winter05/Handou...

> I have a computer science education and I have no idea what you're talking about.

A post-secondary computer science education? I don't mean bootcamp. I mean a course of study in mathematics.

Re: Advent of Code 2025

#365

Post by ngrislain »

crystal_revenge wrote: post #248
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).

For me (and most of my friends/coworkers) the point of AoC was to write in some language that you always wanted to learn but never had the chance. The AoC problems tend to be excellent material for a crash course in a new PL because they cover a range of common programming tasks. Historically good candidates are: - Rust (despite it's popularity, I know a lot of devs who haven't had time to play with it). - Haskell (t…

Yes, this year I'm going for Lean 4: https://github.com/ngrislain/lean-adventofcode-2025

It's a great language. It's dependent-types / theorem-proving-oriented type-system combined with AI assistants makes it the language of the future IMO.

Re: Advent of Code 2025

#366

Post by alexfoo »

tgv wrote: post #350
12345hn6789 wrote: post #64

It is quite odd to call this advent when it ends halfway into the month rather than on Christmas. But I will have fun doing them either way

I think there's a problem every other day, so it's 1, 3, ..., 23.

No, the puzzles are every day from the 1st to the 12th inclusive.

From https://adventofcode.com/2025/about:

" Why did the number of days per event change? It takes a ton of my free time every year to run Advent of Code, and building the puzzles accounts for the majority of that time. After keeping a consistent schedule for ten years(!), I needed a change. The puzzles still start on December 1st so that the day numbers make sense (Day 1 = Dec 1), and puzzles come out every day (ending mid-December). "

Re: Advent of Code 2025

#367

Post by rootnod3 »

ngrislain wrote: post #365
crystal_revenge wrote: post #248

Earlier quoted context omitted.

For me (and most of my friends/coworkers) the point of AoC was to write in some language that you always wanted to learn but never had the chance. The AoC problems tend to be excellent material for a crash course in a new PL because they cover a range of common programming tasks. Historically good candidates are: - Rust (despite it's popularity, I know a lot of devs who haven't had time to play with it). - Haskell (t…

Yes, this year I'm going for Lean 4: https://github.com/ngrislain/lean-adventofcode-2025 It's a great language. It's dependent-types / theorem-proving-oriented type-system combined with AI assistants makes it the language of the future IMO.

Isn't the whole point of AoC to NOT use AI? Even says so in the FAQ

Re: Advent of Code 2025

#368

Post by davey48016 »

torben-friis wrote: post #320
roman_soldier wrote: post #312

Not a fan of these "Coding for fun" things. Code for a job to earn money, yes, a side project where there is an end goal, yes. This seems like a waste of time for working developer. Maybe it's useful for people trying to learn but also becoming pointless now as all Junior dev roles can be done with AI. I mean do plumbers have an advent of plumbing where they try and unblock shit filled toilets for fun?

>I mean do plumbers have an advent of plumbing where they try and unblock shit filled toilets for fun? No, but you’ll see it for writers, musicians, and the like. Engineering (software or not) can be an intellectually rewarding experience for many. I don’t know why some people find this something to scoff at, would you rather have no pleasure derived from your work?

I can't find it, but this question got asked somewhere (Reddit maybe) about 8-10 years ago, and a plumber took the time to respond that many plumbers are actually very passionate about what they do. They don't specifically unclog toilets for fun, but there are plumbers that spend a lot of their free time on plumbing forums, and even some who have projects experimenting with different ways to install certain things.

Re: Advent of Code 2025

#369

Post by 0xEF »

saberience wrote: post #346
0xEF wrote: post #315

Earlier quoted context omitted.

Comparing previous years, they're exactly what I'd expect, to be honest. Only people serious about completion will...well...complete it. Even if they do not know any code, if you pick something well-documented like Python or whatever, it should not be a tremendous challenge so long as you have the drive to finish the event. Code isn't exactly magic, though it does require some problem-solving and dedication. Since th…

I have to say, I've read many out-of-touch comments on HN over the years but this is definitely among the most out there, borderline delusional comments I've ever seen! The idea that anyone who doesn't know any code would: 1) Complete in Advent of Code at all. 2) Complete a single part of a single problem. let alone, complete the whole thing without it being a "tremendous challenge"... is so completely laughable it m…

I can't begin to describe how valuable your input has been through this whole thread about something you're quite possessive and passionate about, which surely places you in a position to aggressively dismiss any other possible way of looking at it! Wow, love learning about new perspectives on HN!

Wishing you best of luck in AoC, Life and Love but I imagine someone like you doesn't need it, being a complete toolbox and all.

P.S.: Tell your coworkers I'm sorry they have to put up with you.

Re: Advent of Code 2025

#370

Post by saberience »

ryandv wrote: post #364
saberience wrote: post #349

Earlier quoted context omitted.

"Anybody with a computer science education who has seen the prompt Proof. before should be able to tackle this one with some effort, guidance, and/or sufficient time." I have a computer science education and I have no idea what you're talking about. The prompt "Proof." ? Most people who study Comp Sci never use any of what they learned ever again, and most will have forgotten most of what they learned within one or t…

Holy fuck. I should just grow coconuts or something in the remote Philippines. > Most software engineers never use any comp sci theory at all, but especially not graph theory or shit like Dijkstras algorithms, DFS, BFS etc. But we are talking about Advent of Code here, which is a set of fairly contrived, theoretical, in vitro learning problems that you don't really see in the real software engineering world either. >…

I have a bachelor's degree in Computer Science, which I assume is what you are referring to by "computer science education".

My only assumption is that you're really out of touch with the ordinary world of humanity if you think most people are aware of stuff like this:

https://www.cs.dartmouth.edu/~ac/Teach/CS105-Winter05/Handou...

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