The Nineteenth Byte

Example: If you wanted to know how many ordered partitions of 100 into pieces of size 2, 7, or 19 there are, you could check the coefficient of x^100 in (x^2 + x^7 + x^19)^999.

Leaky Nun

> These power series arise primarily in analysis, but also occur in combinatorics (as generating functions, a kind of formal power series) and in electrical engineering (under the name of the Z-transform).

@feersum Oh, nice.

@feersum Is the 999 arbitrary?

Sp3000

@LeakyNun Er... L doesn't need to be scaled up...

Leaky Nun

Why not?

feersum

@LeakyNun Yes, it just needs to be at least 50 (100 / 2).

Sp3000

But I do agree with feersum that I've rarely heard of "generating functions" outside of combinatorics

Leaky Nun

6:01 AM

Should I change my question then?

feersum

Well, if it's going to have the factorial scaling, maybe there's no point in changing it.

wizzwizz4

@zʏᴀʙiɴ101 I'm here now! :-)

Leaky Nun

@feersum I mean, just s/generating function/power series/

feersum

@LeakyNun I know.

zʏᴀʙiɴ101

@wizzwizz4 :D

Leaky Nun

6:03 AM

@feersum Oh, I think I know why I used the term generating function

It's because OEIS uses it a lot.

Especially Exponential Generating Function

they just write G.f. and E.g.f.

feersum

Yes, since OEIS is heavily combinatorics-focused.

Leaky Nun

But they write g.f. even for non-combinatorics content, I believe?

feersum

Eh, you could call almost anything with integer series combinatorics; it's a sufficiently broad and vague term...

Leaky Nun

Alright.

@Sp3000 Alright, I really need to write it out.

Sp3000

What I had before was just ordinary polynomial division, but I scaled the coefficients down by a factorial before starting because the input's coefficients are scaled

Leaky Nun

6:12 AM

What's the difference between scaling down the coefficients and scaling up the coefficients?

Sp3000

Oh, er... in this context I just mean dividing/multiplying by the appropriate factorial for that index

Leaky Nun

Yes, I understand, but why does mine not work?

feersum

I wonder if the trick I used for polynomial multiplication here would also work for division.

Leaky Nun

I thought about it too

Fatalize

6:26 AM

My rep, it's over 9000!

Leaky Nun

@Fatalize Félicitations!

Fatalize

@LeakyNun Thanks, you dropped a ´ though

Adnan

@Fatalize It's 8998?

Fatalize

Lol wtf

as I say that I just lost 30 rep

Adnan

Oh hahaha

Fatalize

6:28 AM

I need to wait a few days without winning any rep

Then I can set the winner of this challenge

And have 9000 exactly

This challenge got deleted 10 mins ago, so that's why

"closed as too broad by Eᴀsᴛᴇʀʟʏ Iʀᴋ, Adnan, Alex A.♦"

Adnan

oh sorry :p

Fatalize

ಠ_ಠ

(pretty bad challenge though)

Adnan

It was just a mod 2 challenge

Sp3000

I wouldn't mind an actual even/odd challenge tbh, but I don't think the rules were specified well unfortunately

Fatalize

ez green points

zʏᴀʙiɴ101

6:32 AM

Challenge idea: golf a blog.

Leaky Nun

@Sp3000 Do you mind if I link to your implementation?

Sp3000

shrugs I'll probably be golfing it later when I have time, unless feersum beats me to it :P

Upgoat

@DrGreenEggsandIronMan oh. I'm sorry, I didn't know you were interested in cheddar. What system are you running? Trying installing from the cheddar website and just read up on the docs at docs.cheddar.vihan.org, if you spot any bug. Leave a issue on GH and describe your version (cheddar -V), system, and the code to cause the bug

zʏᴀʙiɴ101

7:05 AM

XAMPP is cool.

I own a lot of ports with me.

> Bad request!
>
> Your browser (or proxy) sent a request that this server could not understand.
>
> If you think this is a server error, please contact the webmaster.

Well, somehow.

Helka Homba

Uploading 4k video takes ages :/

zʏᴀʙiɴ101

@HelkaHomba Wow, you have a 4K display? :O

Helka Homba

@zʏᴀʙiɴ101 No, just 1080. But apparently upsampling to 4k will make the video clearer on Youtube to those who have the bandwidth to watch 4k. I'm testing a bit to see if it's true.

zʏᴀʙiɴ101

Oo.

feersum

4K Minecraft videos are what the world needs.

Leaky Nun

7:14 AM

@HelkaHomba post a challenge! (sorry for randomness)

Helka Homba

@LeakyNun I was gonna make a pop-con, but that'll have to wait until tomorrow

zʏᴀʙiɴ101

@LeakyNun He can't have a challenge every day, not every two days either.

Leaky Nun

@HelkaHomba what about a kolmogorov?

Helka Homba

@LeakyNun You could make one :P

Leaky Nun

cool

zʏᴀʙiɴ101

7:17 AM

In the words of the Breadbaker: "If this won't be a severe situation, I'll take back the toaster."

And before you ask, yes, I do watch Nickelodeon. c:

Leaky Nun

@feersum You know, even J has e.g.f. code.jsoftware.com/wiki/Vocabulary/tco

Helka Homba

@LeakyNun Output a keyboard: (probably dupe)

` 1 2 3 4 5 6 7 8 9 0 - =
   q w e r t y u i o p [ ] \
    a s d f g h j k l ; '
     z x c v b n m , . /

orlp

@HelkaHomba that's not my keyboard

Helka Homba

@orlp I know. But no loopholes :p

zʏᴀʙiɴ101

@orlp wkr :P

Sp3000

7:27 AM

8

@HelkaHomba that's not my keyboard D:

Helka Homba

@Sp3000 You typed that fast for only having 0 and 1 keys

Leaky Nun

@HelkaHomba People type 100wpm on morse code

(exaggerated)

(maybe not)

Helka Homba

@LeakyNun Have we confirmed Sp is people?

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

"01_firstHole" Challenge for Performance Golf First there was code golf. Now, there is Performance Golf. FORE! Motivations This is a crowd-sourced approach to easier and better performance troubleshooting. Performance problems are everywhere, so java technicians need access to easy-to-use d...

zʏᴀʙiɴ101

I'm making a SUSE Studio appliance.

New Main Posts

7:42 AM

1

Q: Wait a minute – in less than ten seconds

Task Using any type of parallelisation, wait multiple periods, for a total delay of at least a minute (but less than a minute and a half). The program/function must terminate within 10 seconds and return (by any means) two values: the number of seconds elapsed, and the total executed delay time...

zʏᴀʙiɴ101

I need a better name for that than Andrew's openSUSE Leap 42.1, JeOS. :/

O ***, new tag. multi-threading

Does someone here think that this is a responsible creation of the tag?

Sp3000

We have concurrency for one thing

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

This question isn't fair. I want you to tell me the chances of flipping an coin n times and ending up on tails. Naturally this isn't a fair coin. In fact, it isn't even a standard unfair coin, where the chance of flipping tails is always p. This is a sticky coin, where the chance of the coin st...

Quill

8:00 AM

I put together a list of extensions for Stack Exchange

2

orlp

zʏᴀʙiɴ101

I need a name for my new SUSE Studio appliance Andrew's openSUSE Leap 42.1, JeOS. :/

Zgarb

@zʏᴀʙiɴ101 What does it do?

zʏᴀʙiɴ101

@Zgarb This is an operating system, made online and based on openSUSE Leap 42.1.

It's very basic, with Python and cURL so you don't get tired.

Zgarb

"AndrOS"

zʏᴀʙiɴ101

8:12 AM

Ah, and also Vim.

@Zgarb Heh.

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

Don't spend time beating a wall, hoping to transform it into a door code-golfascii-art Given an ascii art of a room, determine how many doors are open and how many are closed. Input: String of ascii-room. Output: Two integers; first one being the amount of open doors, second amount of close...

zʏᴀʙiɴ101

Alright, building AndrOS (bo Leap 42.1) now...

bo ==> based on

zʏᴀʙiɴ101

8:26 AM

Still building...

zʏᴀʙiɴ101

8:37 AM

Still...

Zgarb

Are you compiling the Linux kernel as part of the build? Apparently that takes up to 2 hours.

zʏᴀʙiɴ101

@Zgarb Nope, the kernel is already compiled.

It is included into AndrOS as a package.

zʏᴀʙiɴ101

9:02 AM

Finally finished the build.

Zgarb

Does it work?

zʏᴀʙiɴ101

I don't know.

I can't afford a test drive without Flash Player.

Appliance AndrOS (bo Leap 42.1) published here.

In the meantime, looking for beta testers with the test drive feature or a virtual machine available.

Leaky Nun

@Zgarb

Zgarb

9:17 AM

Yes?

Leaky Nun

I just posted a new challenge.

Zgarb

:O

Leaky Nun

0

Q: Golf the Zgarb function

This question is dedicated to the all-time J master @Zgarb. Zgarb's icon is this function: Now it will be called the Zgarb function. It is actually Euler's totient function (number of positive integers less than x co-prime to x) applied n times. Therefore, you will take two positive integer...

code-golf number-theory

Zgarb

I'm not sure I deserve the label "all-time J master", but thanks for the honor!

Leaky Nun

You deserve it :)

Mᴀʀs Uʟᴛᴏʀ

9:25 AM

@Quill 0/10 you should look in stackapps under scripts

Leaky Nun

@Zgarb Are you planning to do it (in J)?

New Main Posts

2

Q: Golf the Zgarb function

This question is dedicated to the all-time J master @Zgarb. Zgarb's icon is this function: Now it will be called the Zgarb function. It is actually Euler's totient function (number of positive integers less than x co-prime to x) applied n times. Therefore, you will take two positive integer...

code-golf number-theory

Mᴀʀs Uʟᴛᴏʀ

@LeakyNun but that's binary

Leaky Nun

@MᴀʀsUʟᴛᴏʀ A prefix code could be memorized easily.

Mᴀʀs Uʟᴛᴏʀ

Morse code is annoying without more unique equipment

@Sp3000 0/10 why emu, not cassowary?

Zgarb

9:32 AM

@LeakyNun Maybe. I'm busy at the moment (I actually have to leave now), but I'll do it later if J isn't taken already.

Leaky Nun

Alright.

Sp3000

@MᴀʀsUʟᴛᴏʀ Emu's only found in Australia, I think (also it's the more prominent bird, seeing how it's on the 50 cent piece)

Quill

10:08 AM

@MᴀʀsUʟᴛᴏʀ the idea is that they're up to date and it's a curated list

Leaky Nun

10:34 AM

Guys, should I make another challenge for the real Zgarb function?

Sp3000

No :/

(also, I'm interested in this "algorithm" you speak of, because I'm pretty sure it's not shorter than repeated application in most languages)

Leaky Nun

I just realized that I made a mistake, so no algorithm

zʏᴀʙiɴ101

Security news: Attackers may have been able to log into your GitHub account.

I'm counted out because of the second factor of authentication.

@Quill I found that the StackExtended repo been made public, and forked the repo.

I have. To...

Fork all the just public GitHub repos! (Meme image in progress)

Sp3000

@LeakyNun btw the reason I say is because we have sigma_0: codegolf.stackexchange.com/questions/64944/…

(didn't mean to link a specific answer, but I'll stop editing cos it pings)

Quill

I was shocked to find out TNB wasn't in my favourite room list o_O

ArtOfCode

10:45 AM

Does anyone want the Concaten room?

zʏᴀʙiɴ101

@ArtOfCode QPaysTaxes long hasn't visited chat, so -.(o.o).-

Quill

@ArtOfCode the author hangs out in SO chat if you want to ask them

zʏᴀʙiɴ101

@Quill So apparently, he did visit chat. Interesting... writes in notebook

Aaaaah, so much better.

Leaky Nun

@Sp3000 Alright.

Lembik

hi all

zʏᴀʙiɴ101

10:58 AM

hi part of all

37 seconds.

Lembik

:)

Has there been a challenge to interpret regular expressions?

I am thinking of something that translates one into English

or maybe there is already a tool that does that?

Leaky Nun

10

Q: Compile Regexes

In this task you have to write a program that reads a regular expression and generates another program that outputs whether an input string is accepted by that regular expression. The output must be a program written in the same language as your submission. Input The input is a regular expressi...

code-golf generation regular-expression

Lembik

that's not the same is it?

Input: [A-Z]{2,4}[FGHJKMNQUVXZ][0-9]

Output: 2 to 4 capital letters following by one of the letters FGHJKMNQUVXZ
followed by a digit

that sort of thing

hmm.. or how about one that outputs random examples of a regex

I like that more

Leaky Nun

Alright.

Fatalize

11:29 AM

ok now I have over 9000 rep

no more deletion pls

Zgarb

@LeakyNun @Mego @LuisMendo My avatar comes from the shift operator that's used in symbolic dynamics.

Does Luis ever visit the chat? I don't remember ever seeing him here.

zʏᴀʙiɴ101

in TAC (The Acronym Chat), 51 secs ago, by m654

ROTFLBTCDICAJTTWADBSIHPWTRHITSBKABAYB (Rolling on the floor laughing biting the carpet dancing in circles and jumping through the window almost dying by smashing into HP who's then running horrified into the street being killed accidentally by a yellow bulldozer)

The longest acronym in the world.

Sp3000

@Zgarb @LeakyNun I take that back - if you can turn that into a challenge, go ahead :P

Lembik

11:46 AM

ok so.. how about this code-golf challenge. Given a regular expression, generate all possible strings that it can match?

views please?

Fatalize

@Lembik what if an infinite number of strings match?

pretty much anything with a + or *

Lembik

@Fatalize a nice question.. I suppose it should output forever

is that a problem?

Sp3000

18

Q: Evaluate the number of possible strings a regex can match

In a chatroom with a few people, a topic came up between me and them about how many possible strings a regex could match. Your task is to build a program that can answer that question. Your program will accept, as input, any regular expression as defined in this document as an "extended regular...

code-golf

(related)

Lembik

3370! :)

Fatalize

@Lembik For some languages no, but I guess it could be for others

Lembik

11:49 AM

@Fatalize as in esolangs?

Fatalize

Can you also wait until I make a regex match built-in before posting it? :p

Lembik

I never worry too much about the existence of languages that are ill suited to a particular challenge

Java is normally one :)

@Fatalize of course!

Fatalize

@Lembik Just kidding I have no idea when/if I will implement it :p

Sp3000

Yeah, I don't think even I'd worry about trying to write a regex engine in FRACTRAN, say :P

Fatalize

@Lembik What about flavours of regex and things that don't exist in certain regex flavours?

Zgarb

11:52 AM

@Lembik I like that idea, but you should restrict to a small subset of regexes. Maybe just literal characters, parentheses and +*?| operators.

Fatalize

^

Lembik

@Fatalize Hmm.. I was thinking BRE

is that too much?

@Zgarb is BRE too much?

I have a preference (that is well known now) for questions whose answers could actually be useful to someone :)

Fatalize

@Lembik "ppcg" "useful"

Lembik

@Fatalize well.. see my previous questions :)

@Fatalize there is a lot of talent here .. just needs to be gently directed

Fatalize

@Lembik Lembik secretely getting work done through PPCG challenges

Lembik

11:55 AM

@Fatalize yes! Making millions!!

:)

I do like to use the internet selfishly to learn things

and provide information that other people can learn from too

call me weird :)

Zgarb

@Lembik BRE seems to have capturing groups, which may be too complex to implement without using a regex engine. I'd prefer if other approaches were competitive too.

Lembik

interesting.. the question may be too complicated for me to implement :)

Luis Mendo

@Zgarb I do visit the chat. Thanks for the explanation!

Lembik

feel free to steal it from me and make it good

Zgarb

If I only had the time... :/

Lembik

11:59 AM

I hear you brother/sister

Zgarb

The former.

Lembik

on the internet everyone is a dog :)

2

Fatalize

@Lembik Meow! (I beg to differ)

TimmyD

12:22 PM

@AlexA. Interesting stuff. I've personally got a Cygwin install setup that I use when I need something separate/outside of what I normally use, and I feel comfortable enough with the arrangement (and I use it seldom enough) that I don't feel a need to change. I'll pass it along to some of my programmer friends, though!

Leaky Nun

1:01 PM

@Zgarb Well then, I apologize for misinterpreting your avatar.

@Sp3000 Alright, after I've understood what it is.

Sp3000

:P good luck

Leaky Nun

@Zgarb Is it like a caesar cipher, if I understand correctly?

flawr

WARNING: Stoat Kills Four Baby Woodpeckers - #Springwatch - Earth Unplugged

►

Eᴀsᴛᴇʀʟʏ Iʀᴋ

minus won not plane crash

flawr

you're the first won to spell won right

Fatalize

1:11 PM

@EᴀsᴛᴇʀʟʏIʀᴋ wut

flawr

@EᴀsᴛᴇʀʟʏIʀᴋ birds are just biological planes

birds-are-bio-planes

Eᴀsᴛᴇʀʟʏ Iʀᴋ

@AlexA. is this true??

Bálint

Is there a challenge about "compiling" regexes?

Sp3000

Yes (scroll up - was just talking about that)

Leaky Nun

Languages are really just a bunch of built-ins.

Eᴀsᴛᴇʀʟʏ Iʀᴋ

1:20 PM

¯\_(ツ)_/¯

flawr

@LeakyNun That bunch can be larger or smaller.

Compare brainfuck to mathematica

Leaky Nun

Really, two characters (commands) is the minimum.

Is already turing complete.

TimmyD

People of chat, can you lend assistance? Do we have a ruling on Meta regarding multiple runs of the same code need to execute, without doing human intervention work in between?

Sp3000

We have a meta somewhere saying functions need to be reusable, if that's what you mean

Leaky Nun

Are you referring to this challenge?

11

Q: Wait a minute – in less than ten seconds

Task Using any type of parallelisation, wait multiple periods, for a total sleep time of at least a minute (but less than a minute and a half). The program/function must terminate within 10 seconds and return (by any means) two values: the number of seconds elapsed, and the total executed sleep...

code-golf date multi-threading

TimmyD

1:30 PM

For example, in PowerShell when you create jobs (via threading), the job histories hang around so you can go back at them later. This is messing up my calculations if the job histories hang around from run to run unless I manually Get-Job | Remove-Job in between runs.

Yes, that's the challenge.

Sp3000

Aforementioned meta

Not sure about full programs though

TimmyD

Hmm

Leaky Nun

1:51 PM

@Dennis Your turn.

TimmyD

Argh. I think I'm going to need to abandon the Wait a Minute challenge. The results are too inconsistent in PowerShell.

Fatalize

@TimmyD Why are you obsessed with PowerShell?

Where does it come from?

El'endia Starman

@Fatalize He Powershells for work.

TimmyD

Yep.

Fatalize

hmm

El'endia Starman

1:59 PM

@LeakyNun You can get by with one. See this:

One instruction set computer

A one instruction set computer (OISC), sometimes called an ultimate reduced instruction set computer (URISC), is an abstract machine that uses only one instruction – obviating the need for a machine language opcode. With a judicious choice for the single instruction and given infinite resources, an OISC is capable of being a universal computer in the same manner as traditional computers that have multiple instructions. OISCs have been recommended as aids in teaching computer architecture and have been used as computational models in structural computing research. == Machine architecture == In a...

Fatalize

I don't like using languages I work with on PPCG, afraid of getting bad habits

Leaky Nun

@El'endiaStarman You need the null byte.

El'endia Starman

@LeakyNun You mean to mark the end of a file? No, you don't.

At least, not on modern systems.

Leaky Nun

What I had in mind was unary

TimmyD

@Fatalize I don't "code" code -- it's all minor scripts, or one-line commands to do something in Exchange or AD, or the like

I've found that I've actually learned some about PowerShell and .NET by working through golfing problems here

TimmyD

2:12 PM

OK, I think I've figured out what's causing the inconsistency. Calling Start-Job apparently has to load some .NET assemblies if it's a fresh shell, which kills the runtime. Re-running the command in the same shell afterward works fine.

flawr

@El'endiaStarman Already awake so early in the morning?=)

zʏᴀʙiɴ101

@flawr Heh, early.

17:14 here.

El'endia Starman

@flawr Hah, indeed. 10:15 AM at this moment, and the reason I've been getting up early is that I'm staying at my fiancée's place while I look for a job in the area since I've had no luck back home in KY.

zʏᴀʙiɴ101

@El'endiaStarman Kong Yong?

El'endia Starman

So my sleep schedule shifted to match hers.

Fatalize

2:17 PM

10:15 is not that early though

Leaky Nun

@zʏᴀʙiɴ101 No, it's 22:17 for me

El'endia Starman

@Fatalize Compared to my previous wake-up times being 12-1 pm, it kinda is. :P

Martin Ender

Not sure if anyone has linked to it yet but codeforces.com/blog/entry/45454 is starting in 1h40 (the language will be announced in 1h10). Figured some people might be interested.

Fatalize

KY = Kentucky right?

El'endia Starman

@Fatalize Yes.

Fatalize

2:18 PM

What's the standard stereotype about Kentuckians(?)?

Eᴀsᴛᴇʀʟʏ Iʀᴋ

musicy?

Martin Ender

This post has a list of languages used in previous contests of that format: codeforces.com/blog/entry/44258

Eᴀsᴛᴇʀʟʏ Iʀᴋ

> Unknown Language: Befunge

hahaha

Fatalize

French wiki says "Kentucky is ranked one in the list of states by gun ownership with 134 guns per 100 inhabitants."

flawr

@Fatalize In a parallel universe, in Kentuky the human ownership is about 100 humans per 134 guns.

7

@El'endiaStarman Does she live so far awar from you or does she just have such a different sleep cycle?=)

Bálint

2:30 PM

I found a chat bug

Where can I report it?

zʏᴀʙiɴ101

@Bálint Meta Stack Exchange

@Bálint Where?

Quill

@Bálint the report might already exist, what is the bug?

El'endia Starman

@flawr She had a typical sleep cycle of 12 AM to 9 AM, and my typical sleep cycle was 3 AM to 12 PM, but now that I'm staying in the same house (for the time being), my sleep cycle has largely shifted to match hers.

Bálint

Whenever I enter the chat, the chat box is already filled up with an old message

Martin Ender

sounds more like a problem of your browser than a chat bug

Quill

2:35 PM

@Bálint browser cache, it's normal to retain the content of the box

Martin Ender

does this not happen in other forms for you?

Bálint

I already cleared my browser history

TimmyD

@Fatalize Bourbon.

Quill

history != cache

hard refresh should do

Fatalize

@TimmyD Alcohol, I presume?

Bálint

2:38 PM

I ckeared the cache and the cookies while clearing history

TimmyD

Bourbon whiskey

Bourbon whiskey /bɜːrbən/ is a type of American whiskey: a barrel-aged distilled spirit made primarily from corn. The name is ultimately derived from the French Bourbon dynasty, although it is disputed whether Bourbon County in Kentucky or Bourbon Street in New Orleans inspired the whiskey's name. Bourbon has been distilled since the 18th century. The use of the term "bourbon" for the whiskey has been traced to the 1820s, and the term began to be used consistently in Kentucky in the 1870s. While bourbon may be made anywhere in the United States, it is strongly associated with the American South...

Bálint

@MartinEnder No, other inout boxes work as expected

TimmyD

> The state has more than 5.3 million barrels of bourbon that are aging – a number that exceeds the state population.

zʏᴀʙiɴ101

2:53 PM

Having fun with EclipseCrossword.

I should have did these in the Sandbox.

Now look in the Sandbox.