The Nineteenth Byte

i wish i started trying competitively earlier cuz i'm doing kind of decently but i forgot until like dec 1 afternoon and i didn't do the first few days as soon as it hit 12 either

Redwolf Programs

I was top few hundred for the first few days but then I messed up once and I've been getting 1k-2k since then

Bubbler

431/1040 today

Does part 2 work with the most naive algorithm, like extract all slices and sum all?

pppery

It's interesting that so far I've earned no points for two days, then earned points for two days, then earned no points for two days, then earned points for two days, and then I earned no points today.

HyperNeutrino

yeah that's how i did it

Bubbler

I was too cautious on that too then

HyperNeutrino

5:19 AM

i got 25/25 today but i could've gotten probably 25/5 if i didn't screw up the second part lol :/

Bubbler

it's still single-digit day after all

Lyxal

Day       Time  Rank  Score       Time  Rank  Score
  9   00:04:21   288      0   00:18:44  2034      0

Unrelated String

Day       Time  Rank  Score       Time  Rank  Score
  9   00:15:47  4032      0   00:19:00  2077      0

I can't read

Lyxal

I screwed up a little on part 2

Unrelated String

same

I summed the first and lasti nstead of min and max

HyperNeutrino

5:19 AM

SAME

Lyxal

yep same

HyperNeutrino

that lost me like 20 places

i am troll

Bubbler

I went ahead with cumulative sum, add the target value, and set intersect to find the range

too much pre-optimization ;_;

Unrelated String

;_;

HyperNeutrino

rip

Lyxal

5:20 AM

Okay who else used itertools.permutations?

pppery

I screwed up a little on part 2, but was so far behind on part 1 it didn't matter.

Redwolf Programs

Day       Time  Rank  Score       Time  Rank  Score
  9   00:06:46   964      0   00:13:11   923      0

Bubbler

I used an equivalent of that in Factor

Unrelated String

I imported itertools but I never remember what's in it

Bubbler

oh, no it's actually itertools.combinations

Lyxal

5:21 AM

And there's a bigger gap now

HyperNeutrino

see i wish i thought of that but no i just used a double loop lmao

Lyxal

between day 9 and ten

pppery

I've never imported anything so far.

HyperNeutrino

yeah idk what's up with that

pppery

Although I had imported like 5 modules by day 9 in 2019

Redwolf Programs

5:22 AM

I guess it's cause we're on a plane

So we're moving fast

pppery

We were moving through outer space last year and there was no gap

HyperNeutrino

i really hope that machine code problem from last day isn't recurring...

Redwolf Programs

Or the challenge author is falling into a black hole and the gap represents how many days they're experiencing

HyperNeutrino

anyone have any idea how to approach this problem part 2? adventofcode.com/2015/day/19#part2

Unrelated String

it took me ten minutes to realize that the preamble wasn't supposed to produce the sums of every single number in the list

Bubbler

5:23 AM

if the gap increases exponentially every day...

Lyxal

@Lyxal aww my markdown didn't work

aww it still doesn't work

Redwolf Programs

Multiline messages can't have markdown

Lyxal

**I thought**
they could

Bubbler

@HyperNeutrino uhh I solved it before but I can't remember the details

lemme check

Lyxal

first 8 days : have a single line gap

day 9 : has a double line gap

day 10 : S P A C E

much better

Bubbler

5:27 AM

@HyperNeutrino Spoiler in my APL solution here

Rahul Verma

Anybody else having problems with Part 1 - desc (part 2), i.e., Suppose the 26th number is 45...

Lyxal

oh wow github has dark mode on desktop now

@RahulVerma they use 1 indexing in their problem descriptions

so if you had a 0-indexed list, it'd be the 25th number

essentially, puzzle_input[25] is equal to 45

Bubbler

Github apparently added a Discussion feature

Lyxal

I saw something about that but I can't find it

Bubbler

which will likely render language developers' other discussion channels useless

You need to enable it in repo setting

HyperNeutrino

5:30 AM

@Bubbler Okay, thanks. I'll have to think about this a bit more

Rahul Verma

@Lyxal yeah, I know that. But, what does this means? Now, for the next number to be valid, there needs to be some pair of numbers among 1-19, 21-25, or 45 that add up to it...

Why not from 20-45?

HyperNeutrino

the first number is 20 so the 2nd to 26th numbers are all of [1, ..., 25] excluding 20 and then also the 45

Bubbler

@HyperNeutrino A vague hint is that the input has some structure to exploit, and it has to do with inert gases

HyperNeutrino

ah okay. ooh i think i see. thanks

Lyxal

@RahulVerma it is assuming 20 is the first number

so the first 25 is 1...25 (with 20 at position 1)

and then the 26th is 45

Initial list: [20, (numbers 1-25 in some random order without 20 [24 numbers])]

New list: [(numbers 1-25 in some random order without 20)[24 numbers], 45]

@RahulVerma does my explanation make sense?

Rahul Verma

5:35 AM

@Lyxal yeah, of course! But, I still couldn't get why 20 is removed...

Lyxal

@RahulVerma here's another way of thinking about things:

Bubbler

20 was the first item, and the window of size 25 is moving forward

Lyxal

the inital list could very well be [20, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24, 25]

the 26th number is 45

making the list [20, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24, 25, 45]

but only the last 25 items are considered

Bubbler

so when you move, you include the next number and lose the first one

Lyxal

so the sum has to be in [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24, 25, 45]

Which is 1-19, 21-25 and 45

wow pppery just left and simultaneously re-entered the room

Rahul Verma

5:39 AM

Oh yes, @Lyxal @Bubbler I got it. So, I'd to push numbers from sample inputs every time?

and remove the smaller of them?

Lyxal

no

remove the first and add the next input to the list

Razetime

@Bubbler did not know that the AOC questions got this hard

Bubbler

not smaller, just first in the order given

Rahul Verma

means the one with lower index

Bubbler

Yeah, it gets significantly harder in later half

Razetime

5:40 AM

oh well

better fasten my seatbelt then

Lyxal

@Razetime why else do you think I only got up to this day last year?

@RahulVerma think of it as a 25 item stack

which disposes of the numbers at the bottom it doesn't have space for

Bubbler

I'm waiting for the moment the difficulty skyrockets, so I have a better chance of higher rank

5

Razetime

@Bubbler big brain play

Bubbler

@Lyxal No, 25 item queue

Lyxal

each time you push a new number from input, it drops the bottom of the stack

@Bubbler that too

@Razetime that may or may not be what I'm counting on for high ranks

Bubbler

5:42 AM

Actually Python has such a size-bound queue, so if you fill it in and push a number, the last one automatically pops out at the back

Rahul Verma

@Lyxal Okay great, feels I should try it now :-)

Initially, [1..n] should be in order, right?

Lyxal

no

it isn't neccesarily sorted

Redwolf Programs

It depends on the input you get

Bubbler

no, the initial part is the first 25 numbers in the input

Unrelated String

the random sized range is just the example given

it's not real

Rahul Verma

5:44 AM

ok, so this is preamble for the example given: 35
20
15
25
47

Unrelated String

yeah

er

Lyxal

that says it focuses on only 5 numbers

Unrelated String

different example

Lyxal

here's the preamble from my input

it'll probably be different to yours

Unrelated String

the thing i missed for 10 minutes that you should be sure to mind is that the preamble is just the part of the input you don't consider for finding the animaly

Lyxal

5:46 AM

say, have you viewed your puzzle input yet?

Unrelated String

there's nothing else special about it

Lyxal

the preamble helps initialise the list you use to find sums

Rahul Verma

@Lyxal yeah!

@Lyxal no, I'm try my code first on the example (n=5)

Redwolf Programs

Just be sure to start checking after 5 instead of 25, and to change it back for the real input

Rahul Verma

@RedwolfPrograms sure :p

Bubbler

5:58 AM

Tried naive approach, it did work but apparently it takes 10 seconds

HyperNeutrino

yeah it's definitely not fast

did you increase start index or slice length first

Bubbler

I used a builtin which apparently gives them in slice length order

Redwolf Programs

My approach was to find the start index, then find the slice length, then the min and max of the slice

Unrelated String

same

Rahul Verma

If in the example, I remove 15 and add 40, then I couldn't find two numbers adding upto 62..

preamble

35
20
15
25
47

Unrelated String

6:05 AM

i stopped increasing slice length at each index once the sum was over the target so it didn't take too long

still a bit slow but more like 1 second than 10

Redwolf Programs

I just checked every slice length up to a thousand, it only took a few seconds I think

Unrelated String

come to think of it the target was huge so maybe i should have started the index somewhere in the middle then moved it outwards in either direction
but that would have taken way longer to type than the runtime it could have saved

Rahul Verma

@Bubbler what I'm doing wrong in the ^ case?

Bubbler

Again, you're supposed to remove the number that appears first, not the smallest one

so you add 40 at the bottom of the list and you remove 35 which is at the top

Rahul Verma

6:24 AM

ok, got it working now, thanks

Rahul Verma

6:39 AM

Got both stars, second was a bit easier!

Thanks to @Bubbler, @Lyxal :D

Razetime

6:54 AM

@RahulVerma once you figure out the first it's not that hard :)

New Main Posts

10:03 AM

0

Q: How can I compare a screen copied Unicode symbol with a pre-defined Unicode symbol in AHK? Thanks

How can I compare a screen copied Unicode symbol with a pre-defined Unicode symbol in AHK? Thanks. Hi, I am using this website as a test base for my AHK code https://www.mathsisfun.com/numbers/math-trainer-multiply.html I want to write a AHK code to check the maths operator, to see if it is a mul...

unicode

Lyxal

10:50 AM

@HyperNeutrino I have a question for you.

why?

Neil

do only the first 100 correct answers score on AoC? that makes it very timezone dependent, no?

Razetime

11:07 AM

@Lyxal This exceeded all my expectations

slowing meglovania a tick woulda made it even better

Lyxal

11:26 AM

@Neil that's right

caird coinheringaahing

11:46 AM

@Lyxal I get why the memes page was deleted, but it is a great page to browse to see the golden days of the site :P

For example, why this so-so challenge has +40 and only 6 answers (4 from 2015)

Razetime

11:58 AM

@cairdcoinheringaahing It is disappointing to know that I turned up here after this was deleted

caird coinheringaahing

@Razetime You're 10k+ right?

Razetime

MEMES

caird coinheringaahing

Have at it

Razetime

If only I could add memes

17

Q: A fiercer four-square cipher

Background One-hundred and thirteen years ago, amateur cryptographer Félix Delastelle published his work on the four-square cipher, a digraphic substitution cipher that accepts two permutations of a 25-letter alphabet as keys and encodes messages consisting of those letters. Like most pen-and-p...

code-golf cryptography

This one needs more answers

caird coinheringaahing

> I call Mama Fun Roll. – Mama Fun Roll Nov 3 '15 at 3:46

Iconic comment :P

Razetime

12:16 PM

molarmanful lol

Neil

heh Vote To Close is an anagram of Coolest Veto

caird coinheringaahing

@Neil I don't know if you remember this or not, but:

> A vote to close is the coolest veto! – Neil Feb 25 '16 at 21:37

:D

Neil

ugh, stupid chat history

Redwolf Programs

1:37 PM

I got a random downvote on my checksum challenge, now I'm no longer at a multiple of ten rep :/

I've also run out of old KoTHs to accept answers on (aside from Bot Factory and Political Simulator)

John Dvorak

the only solution is to downvote eight answers

Razetime

2:14 PM

@JohnDvorak chaotic neutral

Neil

3:13 PM

fun fact, the grub menu gets confused if you turn off num lock as then your arrow keys move double

John Dvorak

Grub menu? Do they sell meal worms in restaurants already?

Redwolf Programs

Already?

caird coinheringaahing

Insects are going to be menu items sooner or later

John Dvorak

I imagine that it would be cheaper in the long run than eating mammals?

Unless you want to switch to full vegetarianism.

Redwolf Programs

We just need to GMO cows which are perfect, stackable cubes

They can double as building materials to save space

Wow, I just realized my reputation graph looks nothing like most people's

Adám

3:28 PM

How can I create a regex that catches a phrase the doesn't contain a certain other phrase? Like [^abc] but for phrases rather than individual characters?

John Dvorak

in which language?

Redwolf Programs

I was just looking for something like that a few days ago, does the flavor you're using have lookahead/behind?

Adám

PCRE

ngn

@Adám ^([^a]..|a[^b].|ab[^c])$

Adám

@ngn Right, but for phrases rather than characters.

John Dvorak

3:30 PM

You can use (?!abc)...

pppery

18

Q: Complement of a Regex

For the purposes of this challenge, we define a postfix regex dialect with alphabet {1, 0} and the following operations: 1 and 0 match themselves literally. _ matches the empty string. ! always fails (i.e. it does not match anything). ab; matches a, followed by b. ab| matches both a and b. a+ m...

code-golf parsing regular-expression

John Dvorak

or rather \b(?:(?!abc)\w)*\w\w\b

Adám

@ngn e.g. abc abc stuff def def should catch the inner abc stuff def for any "stuff" that doesn't have abc or def.

@JohnDvorak Ah, I'll try that. Why the trailing \w\w?

John Dvorak

... right

it will work without it as well

Adám

Thanks a bunch!

New Main Posts

3:36 PM

-4

Q: Recommendation - do you know any place where to buy ready-made articles?

I am looking for a place where I can buy ready-made, unique articles in "flawless" english - something other than PeoplePerHour / fiverr (I'm not interested in outsourcing content creation and assigning topics). I just want to review (at least partially) the available content and choose something...

search word-search

ngn

@Adám it matches 3 chars that are not "abc", but of course ?! is better

Redwolf Programs

4:50 PM

Wow, AoC #8 has almost caught up to #7 in terms of number completed

HyperNeutrino

5:22 PM

@Lyxal why not

Anush

6:58 PM

Hello

Have we had a challenge to compute the BLEU score?

Redwolf Programs

8:59 PM

Does anyone else notice the kerning is really bad for table headers, or is it just because I'm on a low resolution screen?

pppery

@Anush Doesn't look like it, since BLEU only appears in one post, and answer.

Anush

9:35 PM

Cool. I might write a challenge in that case

Lyxal

Morning y'all

Wus popping?

Redwolf Programs

Hi!

Wait, so it's summer right now in the southern hemisphere, right?

Lyxal

That's right

You can practically hear the heat

Redwolf Programs

How hot does it get in summer where you live?

Lyxal

Australia

Redwolf Programs

9:39 PM

Yeah

caird coinheringaahing

It's not exactly know for it's snow

Redwolf Programs

Well yeah, neither is Texas :p

Lyxal

@RedwolfPrograms 40°c+

@RedwolfPrograms that was supposed to be a quantification of temperature

It reaches Australia°c in summer

@cairdcoinheringaahing there's some regions here known for snow

Like "The Snowy Mountains"

caird coinheringaahing

Isn't that from LotR?

Redwolf Programs

Ah, so y'all have the same creativity in naming as our "rocky mountains"?

Lyxal

9:45 PM

Snowy Mountains

The Snowy Mountains, known informally as "The Snowies", is an IBRA subregion and the highest mountain range on the continent of mainland Australia. It contains the Australian mainland's highest mountain, Mount Kosciuszko, which reaches to a height of 2,228 m (7,310 ft) above sea level. The range also contains the five highest peaks on the Australian mainland (including Mount Kosciuszko), all of which are above 2,100 m (6,890 ft). They are located in southern New South Wales and are part of the larger Australian Alps and Great Dividing Range, experiencing large natural snowfalls every winter. Snow...

See

Snowy mountains that have snow

@RedwolfPrograms apparently so

CMQ: What's the most unexpected thing you've found in your toilet?

My answer would be "a lizard"

caird coinheringaahing

10:02 PM

@Lyxal Probably no water

New Sandboxed Posts

10:13 PM

0

A: Sandbox for Proposed Challenges

The math is right, but the answer is wrong (WIP) Choose a mathematical formula. Implement it in such a way that the math is correct, but the answer is wildly wrong due to floating point precision errors or some other defect in how computers operate. I'm not sure how to tag this and have a feelin...

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