« first day (4167 days earlier)      last day (694 days later) » 
00:00 - 16:0016:00 - 00:00

12:01 AM
@AidenChow ...oh
@Bubbler Thanks
Q: ro1000an nu1000era50 en100o501ng

emanresu AIn the hovertext of this xkcd: There's an "encoding" based on replacing runs of roman numerals with their sums. To do this: Find all runs of at least 1 roman numeral (IVXLCDM) Replace them with their sums, as numbers The Roman Numerals are IVXLCDM, corresponding respectively to 1, 5, 10, 50, 1...

Bot slow? Have some butter
12:31 AM
Like why is reddit allowing that :P
12:46 AM
theres a whole r/piracy subreddit they dont seem to care about tbf
> A community dedicated to the discussion of digital piracy.
Actually they seem to piracy as well
They seem to piracy?
Tf kinda sentence is that
Sandbox posts last active a week ago: Strange ponds (WIP), Enumerate the Microwave Timer
1:04 AM
Well in that case, any feedback?
I'd say limiting seconds to two digits is in spirit of the challenge.
Oh wait, you specified that in another part
probably isn't appropriate
1:32 AM
Q: Fibonacci polynomials

alephalphaThe Fibonacci polynomials are a polynomial sequence defined as: \$F_0(x) = 0\$ \$F_1(x) = 1\$ \$F_n(x) = x F_{n-1}(x) + F_{n-2}(x)\$ The first few Fibonacci polynomials are: \$F_0(x) = 0\$ \$F_1(x) = 1\$ \$F_2(x) = x\$ \$F_3(x) = x^2 + 1\$ \$F_4(x) = x^3 + 2x\$ \$F_5(x) = x^4 + 3x^2 + 1\$ Whe...

2 hours later…
3:34 AM
hai guys!
3:45 AM
finally got my first tag-badge - took 2.5 months lmao
4:27 AM
argh, offline for maintenance?
working now
any feedback on this before I post?
1 hour later…
5:38 AM
Hmm, interesting:
What if I make this the longest never-answered code-golf question?
and you have to generate a minecraft file
and you have to do it in brainfuck
yknow i always forget haskells comment syntax is --
6:11 AM
Is this a dupe of thsi?
@emanresuA who cares, just close it
cuz you are not supposed to do "python" IMO iirc
One is a tips challenge and python specific. The other is a standard challenge and language agnostic
They aren't dupes
since when are tips not posted on meta,,,
> Remember, it's very important in code golf not to put any limitations on yourself you don't have to - do what the problem asks, and no more.
Life-changing advice
6:28 AM
@NobodyNeedsNames language-specific challenges are discouraged because sometimes people add a language restriction that adds nothing to the challenge
however, we have those language tags for a reason
tips questions exist and are more often than not language-specific, many if not most KoTHs are language-specific due to the controller's language, and some challenges are specific to a language for a good reason due to how the language works and not just because OP felt like adding unnecessary restrictions
I thought lang tags were koth only, my bad
but like aren;t tips supposed to be on meta>
@hyper-neutrino oh ok
meta is for posts about CCGC, not about code golf
6:32 AM
The poster of this challenge seems to be still active on SO, how should I contact them? Ping in chat?
Should you?
If they posted the original challenge and haven't improved it...
You can leave a comment on the challenge. He will hopefully respond if he reads his SE inbox
@emanresuA idk, it might be more polite
@Bubbler Ah yeah I forgot about comments
hmm okay I'll do that then
6:58 AM
Q: Extract the word containing this index

pxegerFor this challenge, a word is defined as a string of letters, separated by spaces. Given a string of words, and an integer i representing an index into that string, output the whole word which contains the character at index i. For example (using 0-based indexing), with the string code golf, and ...

@mathcat I think given: they're clearly not active on Code Golf, their question is objectively terrible, and they willingly licenced it under CC-BY-SA-3.0, you have every right to repost it without asking
@NewPosts This is infuriating.
@emanresuA Even more infuriating is the fact it's a duplicate.
One of my favourite challenges I've ever come up with :(
7:06 AM
One of mine too
Why the downvote??
@pxeger maybe cuz they saw it was a dupe lol (me not the downvoter)
@pxeger Have a hug
lol thank you very nice
@Zionmyceliaadamancy Did you deliberately change your name shortly before your birthday again, so we can have a sequel to codegolf.stackexchange.com/q/231525?
7:19 AM
Q: How long is it in Roman

pajonkOr Fix American Kennel Club's database As covered by the recent video by Matt Parker, the American Kennel Club permits thirty-seven (37) dogs of each breed to be assigned the same name (source), because of a database restriction for Roman numeral length. Given an integer, your task is to output t...

@pxeger uh,... Yeah totally sure yeah that was definitely the plan when we peer pressured caird into the name change how did you know? :p
Now it should be "move two adjacent characters so that it prints Zionmyceliaadamancy"
And, in reposts, is it okay if some of the wording is the same?
@mathcat uh yeah, why not?
FYI we're gonna hammer the old one as a dupe of your new one
7:30 AM
okay good I was just a bit uncertain
*proceeds to copy-paste the whole challenge*
FWIW, BTW, IMO, you should not make modification #3
@mathcat well u gotta change some of the rules regarding the allowed languages list and bad stuff like that but i think u can just copy-paste the text regarding actual task if u wanted to
@AidenChow yea I was jk
@mathcat :| literally did not realize that, actually so dumb lol
7:33 AM
@mathcat "Take a dictionary and a word as the input"
@AidenChow it's okay. We all miss jokes sometimes lol
I should have /s'd it
@pxeger okay maybe not
what's with the digraph/trigraph stuff? should it be taken as the input too?
@pxeger why not? 7 people think it'd be interesting
or will it just get more complex
@mathcat The trigraph and digraph stuff is definitely unnecessary
7:36 AM
@lyxal *8
All it does is add a little, very basic, but very repeated, pattern-matching task at the beginning
digraph/trigraph stuff???
@emanresuA suggested in TuringMachine23's answer
As I understood it, an input to specify how long a glyph is
@pxeger I see, no.
7:39 AM
Modification #3 makes the challenge less interesting. Digraph and trigraph stuff is completely stupid.
7:56 AM
Q: Is this a strange pond?

Wheat WizardIn this challenge we considered a frog hopping around a lily pond. To recap the lily pond was represented as a finite list of positive integers. The frog can only jump forward or backwards by a distance equal to the number at its current location. So for example: [2, 3, 1, 4, 1] 🐸 Her...

Oh and in the challenge, only words with 8 letters will be listed
Q: Upcoming cleanup of duplicate votes

Yaakov EllisIt was reported on MSO that it is possible for a user to upvote or downvote more than once on a single post (resulting in reputation changes for the author for each vote). After some data examination, we were able to confirm that this vulnerability exists (it is happening due to race conditions s...

What's more impressive is that this has been on the site for so long
@mathcat should that be changed?
@mathcat what do you mean, "listed"?
Those will be the ones you give as examples?
Or answers must only select the 8 letter words?
8:02 AM
no I mean in the original challenge, only words with 8 letters are valid answers for the riddle
I just thought the 8 was a bit random
Yeah, I'd say remove the 8-letter restriction
Actually no, because otherwise, any one letter word will be a valid answer
Maybe change it to be output the longest word which fits those criteria?
nice idea
8:29 AM
@pxeger Let's go with that, instead of people realising how susceptible to peer pressure I am :P
9:03 AM
> susceptible
> sus
I'm sorry I just can't not
A: Sandbox for Proposed Challenges

mathcatWord stays a word after taking away a letter This is a repost of this challenge Challenge There is an old, popular riddle: Find an English word with 8 letters that, taken away one letter, creates a new valid word. Repeat that until there are no letters left. Example solution: starting staring ...

1 hour later…
10:39 AM
@Fatalize what are choice points?
10:51 AM
just realized that there are no fractions in the codepage :/
@PyGamer0 ⌜⊏⊐⊢⌽⊖⍉ aren't monospaced for me
i guess i dont want ⌜⌽⊖⍉
I think it's , but I'm not sure. The last row is much much wider than the others
and i guess i dont need the subscripts ... maybe
i think the subscripts are fine for monospace fonts
11:02 AM
what are you even gonna use 3 sets of numbers for?
@pxeger its the tacks
same thing as brachylog does
@UnrelatedString what does it do?
subscripts modify predicates and superscripts modify metapredicates
o_o what are predicates and meta-predicates
@pxeger i guess i will remove the subscripts
BQN386 has many characters from my codepage
11:18 AM
@Zionmyceliaadamancy is Cathy the baker of The Nineteenth Bakery?
new TNB lore just dropped
1 hour later…
12:23 PM
@pxeger the original already outgolfed me in js :(
tbh i dont understand their approach though so i might just send mine anyway cause its different lol
...hopefully the spec isnt too different
looks like it works /shrug
12:39 PM
wait where's the js solution that beats yours
also that (?<=.{i}) is clever as hell
oh nvm
they forgot to put a space after their struckthrough 43 and i just skimmed past it reading it as a four digit byte count
yep, 4.3KB sounds reasonable
anyhow it seems like l4m2's works by just getting the match's offset within the string because lmao js function parameter design
(and then ofc the ternary is just setting the return value to each in-bounds match in sequence, so that the last one is the one we actually want)
since the seconds will never be more than two digits is it permissible for i/o to be in single integers which are a [minutes, seconds] pair divmod 100
i.e. 1:30 as 130 and such
12:49 PM
@UnrelatedString ty i was pretty proud of that :P its funny though my solution was way less elegant but i kept deleting things and it kept not breaking
like there used to be a bunch of \bs and all that but i came out of the whole thing Enlightened....
In regards to the microwave challenge: should times be required to be sorted?
i'd intuitively lean yes
but i also can't think of a way to exploit no
so i might recommend no just to see if someone does
Is the time limit really needed?
what do you mean is it really needed it's the whole premise of the challenge
12:57 PM
No I mean that seconds should be smaller than 100
i mean my microwave doesnt let me input higher than 99 seconds
idk abt lyxals microwave
it wouldn't fit on a physical display and there's nothing to really gain from going above
@thejonymyster it doesn't either
does it make an iconic sound as well
ah right
12:58 PM
It doesn't add anything to the challenge to remove that limit, and keeping it makes the challenge more "realistic"
@mathcat well it just means that you know there's an upper limit and less edge cases to worry about
Q: Doing a little trolling with the microwave timer

lyxalRelated Sometimes when I use my microwave, I do a little trolling and enter times such as 2:90 instead of 3:30 because they end up being the same time anyway. The microwave happily accepts this and starts counting down from 2:90, displaying times like 2:86 and 2:69 until it gets back to a stage ...

A: Sandbox for Proposed Challenges

lyxalChange the Temperature of Swatchlings Warning: Contains Deltarune Chapter 2 Spoilers Summary Your challenge today is to determine the minimum number of turns needed to change the temperatures of an arbitrary amount of Swatchlings to all be the same. Context In the second chapter of Deltarune, the...

time to go beat deltarune 2 before reading this sandbox
see you in several hours :p
1:06 PM
speaking of sandbox though,
feedback request / specific question about this sandbox, the "pairs at every distance" one,
chunes was suggesting i change the way the distance is defined to be like, a specific metric of distance instead of just "separated by n elements"
i thought this could stand to create more ambiguity, but does anyone have any idea of a clearer way to express it?
to me "n elements apart/away" gives me fencepost counting issues :P
A: Sandbox for Proposed Challenges

py3programmer Hyphens with Interruptions This is a little unusual. You might have come upon simple programs that output a character repeatedly a number of times. This is the same, only with a little twist: interruptions! Your job is to write a program that receives a numeral input, then outputs without newl...

@SandboxPosts weird fizz buzz? :P
seperated seems fine
thx :-)
actually a bit surprised i managed to golf that down 3 and still fgitw
1:12 PM
@UnrelatedString your tio is still that link :P
your g was a little too fitw
it looks fine on my end
hold on my browser is being weird
OK fixed
sorry for falsely accusing you
i will now tear out my heart, as is honorable
wait shit i just realized it's actually broken for inputs smaller than 41 lmao
1:14 PM
wow thats specific
still going to edit the explanation in before reverting in shame
because i only realized that while writing the explanation :P
> This is able to save 3 bytes over a while loop (_41$’ȷ2ḍ$?¹Ð¿) because the final 0 is divisible by 100 and its absolute difference with 41 is 41 which was encountered earlier.
does that work* for any number or just 41?
im so lost lol
the solution works for any input of 41 or more total seconds
but it loops from 41 at the end if it hasn't seen it already
i just dont get whats so special about 41
like why not 52? or 20?
it's the decrement for a flat integer if it's divisible by 100
1:19 PM
@NewPosts @lyxal why ?
Q: Not-Roman-Numeral Addition

bigyihsuanWrite the shortest program or function that mimics the addition in this XKCD strip: Input Two positive decimal integers containing only the digits 150. Output The positive decimal integer result of adding the two inputs together in the manner shown above. This output should also only have the di...

CMP: Feedback ^?
i still maintain that lessorequal and greaterorequal should be swapped :P
also i think you have . twice?
BA and 2E i think
1:33 PM
@PyGamer0 swap the superscripts' position with the Russian lettters & currency symbols? That way null byte is the logical
ah russian letters
at least ill be able to type those
also maybe swap and , so that < = > line up with their logical negations ?
thats what i was sayin :P
is 1F that overline character or is it one of those diacritics
@pxeger ok
@thejonymyster overlije
@thejonymyster it's MACRON according to the GitHub issue github.com/PyGamer0/flax/issues/62
overline would be
1:36 PM
its macron
right sorry
why are there separate chars
i forgot what it was called, i was just seein cause like
Macron is a diacritic btw
@pxeger ok i guess
1:36 PM
oh is it?
Macron is also a language by LyricLy that will probably never be finished
although the one in that codepage is the non-combining version (̄) vs ¯)
my point is that it might go better swapped with B5, since a bunch of other diacritics are over there, and current B5 isnt level with them :P
1:38 PM
plus 1F is surrounded by equality type symbols
I don't like that Ø is there but not ø
oh and there is one more space for a character
@PyGamer0 put ø where is then, and put in the space for the extra char
@PyGamer0 is that why theres two .s?
@pxeger ok nice idea
@pxeger how is it now?
1:44 PM
It's a standard rule for sequences that you can skip or include the input right?
мноп might look too similar to MHOΠ depending on font. You could use some of БДЖИ maybe?
nice bqn386 almost works for my codepage:
@mousetail what do you mean by "skip or include the input"?
@pxeger its all lowercase though
oh well the lowercase versions of those then
they don't look very different
1:45 PM
Like in this answer I skip the first value, for the input (1, 60) I output (1, 59) first: codegolf.stackexchange.com/a/249148/91213
@mousetail standard rules for sequences are at codegolf.stackexchange.com/tags/sequence/info
@mousetail No, I don't think that's standard, but it seems reasonable. Ask @lyxal
@pxeger i think its fine as it is
i would definitely avoid using cyrillic о
I really think they all look too ambiguous tbh
also ordering them лмнопя is funny :P
1:47 PM
@mousetail that doesn't sound like it's in the standard rules
I saw some other posts where it was explicitly listed
they chose to allow it
because it's just a section of the english alphabetical order typed out on like the mac phonetic keyboard layout
Is it ok though?
i feel like sequence challenges don't usually work like this challenge
1:48 PM
@mousetail I'm going to say no to that. The microwave shows the time you input in the sequence it displays, so it should be in the output list — lyxal 18 secs ago
It's more about the type of challenge where every value is the result of applying a function to the previous.
I don't think the tag is appropriate.
@UnrelatedString ok yeah i think i will remove that
@lyxal Sad, ok I'll update it
@WheatWizard Agreed
1:49 PM
@WheatWizard yeah, I agree. I've removed it
Hoped to get my first sub 100 bytes answer
it's kinda unfortunate that a tag automatically associates rules to a challenge
@UnrelatedString now its лмнöпя :P
1:53 PM
@PyGamer0 shouldn't you use ӧ (CYRILLIC SMALL LETTER O WITH DIAERESIS) instead of ö (LATIN ...)?
@pxeger what's wrong here?
> Questions tagged
but it's not tagged sequence (any more)
ah i see, when i clicked the link my browser had me scrolled down
wtf is going on with my browser today
@lyxal Can we skip the (0,0) at the end though?
to that I'll say yes
because irl my microwave displays end instead of 0:00
1:56 PM
can we output end instead of 0:00
> Including [0, 0] or 0:00 is optional.
I have exactly 100 bytes now, really want sub 100
A: Sandbox for Proposed Challenges

pxegerDecipher a squashed series code-golf string parsing number Given a string containing a sequence of ascending consecutive positive integers, but with no separators (such as 7891011), output a list of the separated integers. For that example, the output should be [7, 8, 9, 10, 11]. To disambiguate ...

@lyxal can we beep the PC buzzer instead?
no, but you can beep my microwave buzzer if you want
1:59 PM
What's your microwaves IP?
brb, got to book a plane ticket
@mousetail doesn't have one
@pxeger see you when you get here
I'll leave the gate open and boil the kettle when you arrive
Does it count if I break in and substitute your microwave for a different one?
well sure I guess thanks for the free microwave upgrade
careful of the fridge though
it's radioactive because it keeps getting nuked
if I steal your microwave entirely, can I submit a 0 byte answer?
2:02 PM
Next challenge: build a geiger counter to measure your radioactive fridge
@pxeger uh well I guess
@mousetail here's a few
aw i was hoping theyd use BEL lol
2:14 PM
@RadvylfPrograms thank you for the code!
Can we use the BEL control character to output an actual beep? — Jo King ♦ Aug 5, 2018 at 6:47
if I have sets A and B in python, how can I find the number of things in B that are not in A?
maybe len(B-A)?
yeah len(B-A) seems best
I wonder what the implementation does if B is small and A is huge
2:35 PM
I would think that it would be fast.
IIRC python sets are hash sets.
So lookup should be """O(1)"""
Would make sense to iterate over the smaller of the sets
@pxeger updatedd
in psuedocode this would be the most efficient I think If len(B)<len(A) {i for i in B if i not in A} else {i.remove(j) for j in A}
@mousetail That's pretty much what Python does: github.com/python/cpython/blob/…
I just timed it and it seems python does something sensible!
2:38 PM
O(N) not O(1) though
@pxeger you got there first :)
@mousetail Good luck writing an O(1) set difference function ;)
Maybe with quantum computing
@pxeger define an operation to be one set difference :)
@mousetail It's not really O(N) though. Hash set order notations are really complicated and basically all the numbers are fudged to make them look "faster" than they really are.
2:40 PM
True, hash size increases over time
Which is not to say they are slow, just that they are fast in ways not captured by asymptotic complexity.
same for hash maps, they are not really O(1) in practice
since the hash size increases depending on the size of the collection
Asymptotic complexity and "in practice" are like water and oil. They don't go together.
Same thing happens when you pour asymptotic analysis on a performance fire
don't stand too close
O(99999999) is still O(1) ;)
2:43 PM
which hash function does cpython use?
For integers, its n => n % (2**61 - 1) IIRC
Exact hash values are randomized on startup to prevent hash collision based denial of service attacks
@pxeger that can't be right.
@mousetail only for strings
It needs to know where to put the key, value in memory
2:45 PM
or at least, not for integers
for strings yes
so the range has to be the size of the hash table
i.e. not 2**61
though the specification states you shouldn't rely on them being consistent for any type
@pxeger @graffe This is the base hash function. It then gets re-modulo'd depending on the size of the hash table, I think
2:46 PM
@pxeger oh ok. That's not a great hash function
Python's dicts have a weird layout which makes that not a problem
(or maybe, they have a normal layout, and they just discovered that it's not a problem in practice)
Hmm could you force hash collisions by storing only powers of 2 maybe?
@pxeger I'm sure I saw a good rationale for this by the Python developers somewhere, but I can't find it
It fast
I think it saves memory
2:51 PM
Evidently it's fast, but why is it not slow, as you might expect based on traditional hash table "theory"
There is still a hash table like normal, but it stores only indexes to a separate list that has the hashes and pointer to the keys and values. Double indirection. So you don't need to store both pointers in the table (which is normally half empty)
Murmur3 is popular I think
but I can't remember what Julia just moved to
php used the length of the string in the very beginning
some old functions have odd names just so they would have distinct lenghts
3:40 PM
A: Sandbox for Proposed Challenges

Radvylf ProgramsI X the source code, you Y the output! code-golf source-layout code-generation There's a zillion challenges of the form "I [do a thing to] the source code, you [do a thing to] the output!", like I double the source, you double the output! and I reverse the source code, you negate the output!. In...

3:54 PM
CMP: should negative numbers in Fig be falsey?
!= 0 is pretty useful but > 0 is also often useful (and if you're only dealing with nonnegative numbers, > 0 is the same as != 0
prime numbers should be falsy
jokes aside, negative numbers being falsy is interesting, sure
It's certainly not a crazy idea, it'd be cool if you experimented with them and discovered that falsy negative numbers is better so other golflangs could change their behavior too
Not sure what it'd be useful for though, since the main reason I could see it being handy is making -1 falsy for a non-match in indexOf, but since 0 is also falsy it doesn't work
I considered it for Ash but decided not to since it didn't really help with anything
00:00 - 16:0016:00 - 00:00

« first day (4167 days earlier)      last day (694 days later) »