The Nineteenth Byte

Unihedron

8:00 PM

Amen, Jenny_mathy has a dope hat

caird coinheringaahing

Confirmed. Jenny_mathy's hat is secret

@Mr.Xcoder Amen to that :P

Wait, Howard has a hat?

Sherlock9

8:17 PM

Hm I haven't gotten any hats :(

Erik the Outgolfer

being active helps, that's why the hats exist

winter is generally the time when the site has the least activity, so hats are here to help it a bit

KSmarts

I got two secret hats the other day, and now they're gone.

Erik the Outgolfer

what

that can't happen, refresh perhaps?

PhiNotPi

@KSmarts stealth hats

AdmBorkBork

Schrödinger ~~cats~~ hats.

5

Stupid strikethrough makes it look like Schrödinger eats hats.

Leaky Nun

8:30 PM

Schrödinger hat einen Hut

Mr. Xcoder

@cairdcoinheringaahing I donmt think Jenny Mathy’s hat is secret. It seems to be in the profile picture itself, so I don’t think it is a hat at all (I can see it from mobile)

caird coinheringaahing

@Mr.Xcoder Yeah, realised that when their profile didn't have '1 hat' in it :/

Unihedron

it is a dope hat, not a winterbash hat

Mr. Xcoder

WTH is a dope hat?

AdmBorkBork

A hat that is dope. Keep up. ;-)

KSmarts

8:32 PM

@cairdcoinheringaahing (Posts Sandbox link) ...

(30 minutes later... nothing)

@Mr.Xcoder Alternatively, it is a heroin hat.

Mr. Xcoder

Well, depends on the definition of dope

caird coinheringaahing

Dope means weed where I'm from :P

Mr. Xcoder

Dope can mean Marijuana, Heroin or nice

AdmBorkBork

no dude wtf dont u know drugs r illegal

4

Unihedron

dope means nice

much like how gay used to mean jolly

thanks for ruining english~

flawr

8:40 PM

at least the word english is not used as negatively as french

AdmBorkBork

As in "Pardon my French?"

flawr

haha:)

So what do you think about making a tag for coding-theory? I feel we've had a quite a bunch of challenges where it would fit.

Erik the Outgolfer

how would you define the tag?

flawr

just to clear up possible misconception: coding theory != coding (= programming)

Coding theory is about communication, encoding, compressing etc

DJMcMayhem

@flawr Could you give an example of where you think it would fit?

flawr

8:47 PM

e.g. anything e.g. about the hamming code or gray code, let me gather some links

Pavel

@Unihedron Can I ask where your profile pic is from?

flawr

1 ‌2 3 4

5 6 7‌8 9

@DJMcMayhem challenges that would fit coding-theory^

Unihedron

pan no mimi twitter.com/panno_mimi

Destructible Lemon

dope also means (noun) fool or (verb) enhance (probably why a drug is called dope)

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

Mirrored Digital Clock Many digital clocks display the time using simplified digits comprised of only seven different lights that are either on or off: When mirrored horizontally, the digits 018 don't change, because they are symmetrical. Also, the digits 2 and 5 change places, 2 becoming 5 a...

flawr

9:01 PM

@DJMcMayhem any conclusion? :)

DJMcMayhem

@flawr I like the idea. I haven't looked that closely at the challenges you linked but I think it works. Only thought is that their might be a better name

(information theory? Encoding-theory?) Idk

flawr

encoding theory is something else

information theory is more general, but includes coding theory

New Main Posts

2

Q: Binary Sequences

Given a binary number A as input with d > 1 digits, output a binary number B with d digits according to the following rules for finding the nth digit of B: The first digit of B is zero if the first and second digits of A are equal; otherwise, it is one. If 1 < n < d, then if the (n-1)th, nth an...

flawr

do you mean because people might misunderstand what it is about?

DJMcMayhem

Yeah.

Like you said "Coding" can have multiple meanings

@flawr What is encoding theory?

flawr

9:08 PM

@DJMcMayhem it is also about communication, but in sociology

AdmBorkBork

We have number-theory, which is admittedly pretty broad but seems to fit well here. Maybe information-theory fits better.

flawr

(don't know a lot about it, just knew the name because I know someone working in that field:)

DJMcMayhem

@AdmBorkBork Number theory is waaay broader. Coding theory is about the most efficient/reliable ways to transit data, whereas number theory is stuff like distribution of primes

flawr

@AdmBorkBork I think number-theory does not include coding theory,

and I think information-theory might be just too broad

then again we also have math...

but I mean just adding another very broad tag is not very beneficial

DJMcMayhem

@flawr this?

@flawr Coding theory has my 👍. If you want more opinions, you could always take it to meta.

flawr

9:11 PM

Yes I think this is what I had in mind, but again, I'm not really familiar with that:)

@DJMcMayhem good:) I just wanted to see what people think before I start adding meta-clutter

AdmBorkBork

Right, not saying that number-theory includes coding-theory, just that I wonder if coding-theory is too narrow, and so information-theory may be a better tag in the same reason that we have number-theory.

flawr

I see, well it would really have the advantage of a better name, or at least one that would probably be less misunderstood

AdmBorkBork

That's also true

DJMcMayhem

@AdmBorkBork Can you think of any challenges that would fit information-theory that don't fit coding-theory?

Erik the Outgolfer

btw that color profile bug in chrome 63 is annoying...

flawr

9:19 PM

@DJMcMayhem Actually it seems many courses at universities bear the title "information- and code theory" (or something along the lines thereof)

DJMcMayhem

BTW, speaking of information/coding theory, I remember a really interesting problem I ran into like 3-4 years ago

If you have a huffman encoding, (mapping arbitrary bytes to a sequence of bits of variable length), what is the most compressed possible way to write down the key?

For example, what's the shortest binary way to represent the following:

a: 0
b: 10
c: 11

AdmBorkBork

@DJMcMayhem Sure, one of mine -- Patch the Paragraph as it involves natural language processing and pattern recognition but without any form of coding.

Erik the Outgolfer

@DJMcMayhem that depends on what your representation could represent

DJMcMayhem

What do you mean?

Erik the Outgolfer

for example if it can only represent that table, then 0 bits is the shortest it could get

flawr

9:22 PM

@AdmBorkBork I'm not sure how relevant information-theory would be for this

DJMcMayhem

@EriktheOutgolfer Well obviously. But I mean for any table in a format similar to this

Where you have an unknown number of {byte: bit-sequence} mappings

AdmBorkBork

No, I agree, it's not a perfect fit, but it is something off the top of my head. Alternatively, every single KC challenge is an information-theory challenge, hehe.

DJMcMayhem

But importantly, The bit-sequences form a prefix code. I'm not sure how that could be used to shorten it

Erik the Outgolfer

well, for one, I'd say 11001011

11 = max 2 bits

0 = separator

0 = leading 0 == 00

10 = 10

11 = 11

but others may have a different opinion

that's what I mean

Leaky Nun

it also depends on the nature of the tables you would like to encode

i.e. should we optimize for the size of the table or the length of each element in the table?

DJMcMayhem

9:26 PM

@EriktheOutgolfer I'm not sure that could be uniquely decoded. But more importantly, that doesn't map each sequence to it's corresponding byte, it just tells you what ever bit sequence is

@LeakyNun The size of the whole table

Erik the Outgolfer

@DJMcMayhem oh you need the byte too?

DJMcMayhem

Yes

Leaky Nun

@DJMcMayhem i.e. your tables would typically have a lot of elements?

DJMcMayhem

Because you don't know what the set of bytes used will be

Erik the Outgolfer

@DJMcMayhem then

Leaky Nun

9:27 PM

00 = separator

10 = 0

Erik the Outgolfer

11001100001001100010100110001111 (110 = 2 bits max, 01100001 = a, 0 = leading 0 == 00, 01100010 = b, 10 = 10, 01100011 = c, 11 = 11)

Leaky Nun

11 = 1

10001110001111

I win

Erik the Outgolfer

@LeakyNun and where are the bytes?

Leaky Nun

@EriktheOutgolfer what does that mean?

Erik the Outgolfer

a, b and c are bytes in DJ's example, you should include them in too

Leaky Nun

9:30 PM

oh...

Erik the Outgolfer

that's what I mean with this

8 mins ago, by Erik the Outgolfer

@DJMcMayhem that depends on what your representation could represent

Leaky Nun

I'm out

Erik the Outgolfer

and also how it's understood

DJMcMayhem

@EriktheOutgolfer Hmh, Interesting. But I don't understand how you know when the key is over. Obviously, you can tell if the mapping is the max length, but what if it's shorter?

So what's the significance of the leading 0 in your example?

If you're curious, here's what I ended up doing:

01100001(a) 10 01
01100010(b) 11 10 01
01100011(c) 11 11 00

So 10 == 0, 11 == 1

And 01 == end of key, 00 == end of map

But I'm sure that's not 100% optimal

flawr

10:25 PM

@DJMcMayhem @EriktheOutgolfer @AdmBorkBork on meta: codegolf.meta.stackexchange.com/questions/14400/…

Laikoni

Any feedback on this challenge idea? codegolf.meta.stackexchange.com/a/14169/56433

flawr

@Laikoni would you also allow nested lists, for instance [4,3,2,1] -> [[2,1],[4,3]] -> [[[1],[2]],[[3],[4]]] etc?

Οurous

Or list-like structures in languages where lists are distinct from, say, arrays / tuples?

New Meta Posts

2

Q: Tag Proposal: Information- and Coding Theory

After some discussion in the chat, I propose to create a new tag about Information- and Coding theory. We've already had a number of challenges that would fit this tag very well and I think there are many more to come. It would add context to those challenges that is not possible to express with ...

discussion tags

flawr

@NewMetaPosts Am I supposed to add each a Yes and a No answer such that people could vote?

Laikoni

10:34 PM

@flawr Yes, I'd say this is a reasonable representation, even though it's evil from a Haskell point of view.

DJMcMayhem

@flawr I'd say no, don't post an answer you don't agree with

flawr

@DJMcMayhem so should I add an answer at all? I mean I already voiced my opinion in the post

DJMcMayhem

And posting a "yes we should add this" doesn't add a whole lot, because it's already obvious that you agree with the idea (since it's yours)

Laikoni

@Οurous Yes, an array or tuples would also be fine.

flawr

@DJMcMayhem so I just wait until someone answers or comments, right?

@Laikoni Is there a particular reason you chose Merge sort? (I think there are other algorithms that have a similar way of recursively spliting up the list, right?)

Οurous

10:40 PM

@Laikoni would you want to look at invalidating any merge-sort builtins? I know they wouldn't do the challenge for you, but I can think of a few ways to hook into the merge-sort implementation in Clean to have it return the sorted list and the required output. Clean isn't really the most golf-y language, so I imagine there are ways to do that in others as well.

Laikoni

@flawr Quick sort also recursively sorts two sublists, but there you need to pick a pivot element and compare the other elements to it. So the nice thing about merge sort is that it works no matter how you split the lists, which might be interesting for golfing in some cases.

DJMcMayhem

@flawr Yeah pretty much

flawr

@Laikoni Ah I see, that makes sense:)

Laikoni

@Οurous I'm not a fan of disallowing built-ins, as this usually creates some ambiguity. I also do not think that any language will solve this challenge just by a built-in itself. So if you can use some merge sort built-in creatively to solve the challenge, I'm happy to see the answer.

Unihedron

I think built-ins comes with implementation details which are specific to the tools you use and requires a certain level of mastery and awareness of your language to make use of. Such as perl counting lines in $., knowing these features aren't cheating but rather using the tool the way it's designed for.

They don't introduce unfairness in the sense that they're already there to be studied.

Laikoni

10:57 PM

@Οurous Btw the other day I had a look at Clean, probably after seeing one of your answers, and thought: "The syntax looks quite similar to Haskell". Only now Wikipedia told me that Clean is actually older than Haskell and indeed one of its influencers.

Οurous

@Laikoni Yeah, as strange as it sounds, Haskell is like real-world Clean. Clean is both blessed and cursed by it's development team being a handful of computer science academics.

Christopher 2EZ 4RTZ

anyone want to duel for 50 rep in newline?

@Pavel you want to?

Unihedron

?!?!

do I smell rep

Christopher 2EZ 4RTZ

yes

Pavel

@Christopher2EZ4RTZ Too busy playing rainbow six

Christopher 2EZ 4RTZ

11:03 PM

@Pavel priorities (you got them right)

Pavel

Which I'm streaming by the way: twitch.tv/cat_dev_random

Christopher 2EZ 4RTZ

yay

@Unihedron you game?

@Pavel how much language should I expect? (no headphones)

Unihedron

I think I'll lose, so nah ^^

stakes2high4me

Pavel

@Christopher2EZ4RTZ I won't be swearing if that's what you mean

Christopher 2EZ 4RTZ

@Pavel yeah I just don't want my sister to overhear some rage rant

@Unihedron :_(

Pavel

11:06 PM

I'll try to avoid anything like that

Christopher 2EZ 4RTZ

ok

Pavel

I generally don't yell at my teammates

Christopher 2EZ 4RTZ

i see you don't play much dota then

@DJMcMayhem you want to try?

Pavel

Well I yell at my teammates in Dota :P

Christopher 2EZ 4RTZ

@Pavel good child I say to the person who is ~1 year younger

Pavel

11:08 PM

Yay found a match

Christopher 2EZ 4RTZ

yay

Unihedron

ROUND ONE FIGHT

Pavel

Problem: Teammates are swearing

Christopher 2EZ 4RTZ

rip

Internet is slow so can't watch :(

@Unihedron caps

New Main Posts

4

Q: Visualize Merge Sort

Merge sort is a sorting algorithm which works by splitting a given list in half, recursively sorting both smaller lists, and merging them back together to one sorted list. The base case of the recursion is arriving at a singleton list, which cannot be split further but is per definition already s...

code-golf array-manipulation sorting

Christopher 2EZ 4RTZ

11:16 PM

where is the regex god when you need him :(

micsthepick

@Christopher2EZ4RTZ who’s that? :P

Christopher 2EZ 4RTZ

martin ender

micsthepick

do you need help?

Christopher 2EZ 4RTZ

i need the right side of numbers from this: oeis.org/A002852/b002852.txt

and he has retina the language that will do that but I don't know the language

Leaky Nun

well I do

Christopher 2EZ 4RTZ

11:19 PM

would you do that for me?

Leaky Nun

I mean, even pyth can do it

but sure

Christopher 2EZ 4RTZ

thanks

Leaky Nun

the code is:

\d+ (\d+)
$1

paste your input to the "input"

Christopher 2EZ 4RTZ

thankkkks

micsthepick

@LeakyNun exactly how I would have done it

Christopher 2EZ 4RTZ

11:20 PM

XD

Leaky Nun

@micsthepick hmm... need to golf it then :P

Christopher 2EZ 4RTZ

@LeakyNun dammmn

Leaky Nun

m`^\d+

(with space and newline afterward)

@micsthepick here, golfed it

change \d to . for more golfing

micsthepick

:P

. would match the whole line

Leaky Nun

but the space afterward would tell it to stop

micsthepick

11:22 PM

true

Christopher 2EZ 4RTZ

Ok golf challenge: now take the input and replace every newline with a comma

micsthepick

@LeakyNun have you tried that?

Leaky Nun

m!`\d+$

7 bytes

Christopher 2EZ 4RTZ

how to get people to do my work for me

Leaky Nun

@micsthepick yes

Christopher 2EZ 4RTZ

11:23 PM

(for One OEIS after another)

Leaky Nun

2 mins ago, by Leaky Nun

(with space and newline afterward)

@Christopher2EZ4RTZ after or before removing the indices?

Christopher 2EZ 4RTZ

what?

ohh after you run the first program you run the comma replacement one

@LeakyNun

Leaky Nun

m!M`\d+$
¶
,

(all-in-one)

just take the last two lines if you've already replaced the input

12 bytes

Christopher 2EZ 4RTZ

thanks

micsthepick

new golf challenge: replace a 1 or 2 digit integer with the next integer.

DJMcMayhem

11:28 PM

@Christopher2EZ4RTZ Playing DOTA? nah, I'm good

Leaky Nun

@micsthepick don't get it

Christopher 2EZ 4RTZ

@DJMcMayhem at dota? :P

Leaky Nun

oh

you mean by retina?

DJMcMayhem

@Christopher2EZ4RTZ Ha!

No way

Leaky Nun

I've done that to death @micsthepick

micsthepick

11:29 PM

@LeakyNun if you dare!

DJMcMayhem

Most definitely not good at DotA

Christopher 2EZ 4RTZ

i am ok at it

I only have 400 hours

DJMcMayhem

I might play some GOIWBF right now

Christopher 2EZ 4RTZ

hahah goooooood luck

Leaky Nun

28 bytes

T`xd`dx`.$
+`9x
x0
T`xd`d`.x

tio.run/##K0otycxL/P8/JKEiJSGlIkFPhUs7wbKCq8KACyKUoFfx/…

19 bytes

$
;
+T`;d`d;`.;
0$
(empty)

tio.run/##K0otycxL/P9fhcuaSzskwTolIcU6Qc@ay0CF6/9/Y0MTQ1NLS0sA

@micsthepick?

Christopher 2EZ 4RTZ

11:39 PM

First One OEIS after another answer!!!

micsthepick

@LeakyNun looks good.

Christopher 2EZ 4RTZ

hello

ATaco

@user202729 Although I'm not sure how much this interests you; Funky has now actually got return statements, although their implementation does not break your OEIS solution.

Christopher 2EZ 4RTZ

@cairdcoinheringaahing how was my answer invalid?

annnd my answer is ded

caird coinheringaahing

@Christopher2EZ4RTZ It was decided a few answers ago, that while being technically valid, people should only hardcore if the sequence is finite. The first answer that hardcodes (the Rust one) is at about +10/-10 as an example

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