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Advent of Code 2025: Number of puzzles reduce from 25 to 12 for the first time

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Re: Advent of Code 2025: Number of puzzles reduce from 25 to 12 for the first time

#21

Post by eterm »

thaumasiotes wrote: post #19
thomascountz wrote: post #4

Whenever there's a change like this, my gut reaction is to grieve and try to imagine ways that things could be kept the same. After thinking, "maybe puzzles could be designed by a group instead of an individual and they could share the work," I then thought, "and couldn't an LLM help?" And with that, I had to remind myself: Advent of Code isn't about there being 25 puzzles, and so maintaining volume at all costs has…

> And with that, I had to remind myself: Advent of Code isn't about there being 25 puzzles Really? The name of the event is "Advent of Code". Having 25 puzzles is easily its most strongly-determined aspect. You could argue for 23-29 puzzles, or perhaps for 5, but at 12 what's the name supposed to refer to?

Well advent calendars traditionally had 24 doors.

Re: Advent of Code 2025: Number of puzzles reduce from 25 to 12 for the first time

#22

Post by ozim »

nikanj wrote: post #5

Tryhards ruin everything, part n Make a fun little christmas calendar to bring joy to the people, get turned into a gamified warzone where people use AI and bots to try to get onto the global leaderboards - possibly because getting on them might net you a job at FAANG

Fun part is that world mostly doesn’t really work like that and they don’t really get the job.

Re: Advent of Code 2025: Number of puzzles reduce from 25 to 12 for the first time

#23

Post by sunrunner »

ekimekim wrote: post #9
petesergeant wrote: post #8

Earlier quoted context omitted.

I’ve been trying to design a puzzle for a game this year that humans can solve but LLMs can’t. I’ve come up with one, but it was hard work! It’s based around message cracking.

There was one in a previous AoC that I think stumped a lot of AI at the time because it involved something that was similar to poker with the same terminology but different rules. The AI couldn't help but fall into a "this is poker" trap and make a solution that follows the standard rules.

Was that 2023's Day 7 'Camel Cards' [1]?

[1] https://adventofcode.com/2023/day/7

Re: Advent of Code 2025: Number of puzzles reduce from 25 to 12 for the first time

#24

Post by rich_sasha »

shrx wrote: post #3

One of the reasons I stopped participating was that as the second half of december was approaching I had less and less free time for solving the puzzles. So to me it is also a welcome change, I will try to finish it again this year.

I once has this half serious idea to do "Advent of Parenting", with one problem per month, and you start after Christmas. As in, youre so delayed you start in the New Year, and have time for one problem per month.

But hey I didn't have the time to do it. Kids...

Re: Advent of Code 2025: Number of puzzles reduce from 25 to 12 for the first time

#26

Post by huflungdung »

petesergeant wrote: post #8
thomascountz wrote: post #4

Whenever there's a change like this, my gut reaction is to grieve and try to imagine ways that things could be kept the same. After thinking, "maybe puzzles could be designed by a group instead of an individual and they could share the work," I then thought, "and couldn't an LLM help?" And with that, I had to remind myself: Advent of Code isn't about there being 25 puzzles, and so maintaining volume at all costs has…

I’ve been trying to design a puzzle for a game this year that humans can solve but LLMs can’t. I’ve come up with one, but it was hard work! It’s based around message cracking.

How many s are in the word

Re: Advent of Code 2025: Number of puzzles reduce from 25 to 12 for the first time

#27

Post by matrss »

thaumasiotes wrote: post #19
thomascountz wrote: post #4

Whenever there's a change like this, my gut reaction is to grieve and try to imagine ways that things could be kept the same. After thinking, "maybe puzzles could be designed by a group instead of an individual and they could share the work," I then thought, "and couldn't an LLM help?" And with that, I had to remind myself: Advent of Code isn't about there being 25 puzzles, and so maintaining volume at all costs has…

> And with that, I had to remind myself: Advent of Code isn't about there being 25 puzzles Really? The name of the event is "Advent of Code". Having 25 puzzles is easily its most strongly-determined aspect. You could argue for 23-29 puzzles, or perhaps for 5, but at 12 what's the name supposed to refer to?

IMO "Advent of Code" only determines the timeframe in which it happens, not the amount of puzzles it must contain. It could just as well be four puzzles, one for each sunday of the advent, or any other amount, as long as they are released within those roughly four weeks before christmas.

Re: Advent of Code 2025: Number of puzzles reduce from 25 to 12 for the first time

#28

Post by emerongi »

NoboruWataya wrote: post #12
shrx wrote: post #3

One of the reasons I stopped participating was that as the second half of december was approaching I had less and less free time for solving the puzzles. So to me it is also a welcome change, I will try to finish it again this year.

Same, I love AoC but I just never have time for them (December is always the busiest time of year in my job). I would have liked if a puzzle was released every 2 days though so it still spanned the whole month. Would be more aligned with the advent calendar concept. In fact in previous years the puzzles have always had two parts so if that format is still being retained there will still effectively be 24 puzzles.

Spreading the two parts across separate days would be interesting. There would be an extra element of trying to predict what part 2 will be like.

Re: Advent of Code 2025: Number of puzzles reduce from 25 to 12 for the first time

#29

Post by akho »

thaumasiotes wrote: post #19
thomascountz wrote: post #4

Whenever there's a change like this, my gut reaction is to grieve and try to imagine ways that things could be kept the same. After thinking, "maybe puzzles could be designed by a group instead of an individual and they could share the work," I then thought, "and couldn't an LLM help?" And with that, I had to remind myself: Advent of Code isn't about there being 25 puzzles, and so maintaining volume at all costs has…

> And with that, I had to remind myself: Advent of Code isn't about there being 25 puzzles Really? The name of the event is "Advent of Code". Having 25 puzzles is easily its most strongly-determined aspect. You could argue for 23-29 puzzles, or perhaps for 5, but at 12 what's the name supposed to refer to?

Twelve nights of Christmas. Would also work better for me, calendar-wise :)

Re: Advent of Code 2025: Number of puzzles reduce from 25 to 12 for the first time

#30

Post by sunrunner »

defanor wrote: post #15

On the bright side, this will lead to a more relaxed December schedule. I do not compete for the leaderboard, but trying to solve the puzzles on the days they are released (to keep it in the spirit of an advent calendar), and the puzzles towards the end sometimes take me a considerable chunk of the day to solve, which is tricky to combine with the regular schedule, and may be rather stressful (though still a nicer ki…

This matches my experience, and I've been 'nervously' anticipating this year's Advent of Code. I managed to keep to the spirit last year and get everything done by Christmas day (though admittedly with some days bleeding over into other days due to pesky family/other commitments), but even this relied on having the last week or so of the month be relatively free for me.

While I've usually been able to do the first half of the month's puzzles in the day before breakfast, over lunch and in the evening, the increasing difficulty does mean that later puzzles can really eat into a day, particularly if you happen to go down a bad path for your solution.

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