5:01 AM
Oh I'm using the master-release-develop-feature one I'll find a link

^ is this the one you're looking for?

Yes

@Upgoat I'm slightly offended you didn't want me to be a cheddar beta tester.

@Upgoat okay, next: The jade package has moved to pug.

@LeakyNun ideone.com/NfvP02 Close enough

5:19 AM
@Sp3000 Does it have to be floating point?

Easier :/
Maybe there's a way to keep it in integers
Haven't thought too hard about it though, got other stuff to do

It is guaranteed to be an integer
so you can just multiply the factorial instead?

zyabinVI poll here: instant.ly/s/w9hDX
It ends today at 19:30 UTC+3, so be fast.

@Sp3000 You know, it would be much easier to read had you not used single-letter variables.

Couldn't make up my mind whether to golf or not :/

5:33 AM
first, make it integer.

Beautiful. I'm writing it as well.

(The number of times I wished Python had a binomial coefficient function...)

Why is it needed?

`F[i+j]//F[j]//F[i]` (`F` is factorial here)

5:42 AM
But why is it needed?

Because it's an egf rather than a regular gf, which is why I said it's like polynomial division but "you need to watch the factorials"

So it is not related to n choose k?

why are you guys calling them generating functions rather than power series?

because that's how I termed it

Because that's the term Kenny's using in the question

5:45 AM
@LeakyNun Begging the question...

@feersum Because I didn't know such a term exists.
Plus, power series is too general

I would have termed it inverting a formal power series, except for the random factorial scaling on the coefficients.

It is not a random factorial scaling.

@LeakyNun Can you explain why not?

Because each term does have a factorial.

5:49 AM
I am asking why it is less arbitrary than saying, e.g. that all the inputs must be divided by 3.

Because each term does have a factorial. When you make the taylor series, you divide each term by the factorial

yo @Upgoat, you around?

@Quill I'd ask the same question. :/

@LeakyNun But the strange part is how it is combined with the term generating function which is associated with combinatorics.

@feersum This you should ask mathematica.

5:55 AM
Factorial scaling might be convenient when you are analyzing real or complex functions but why would you want it in combinatorics?

My challenge is not related to combinatorics at all.

But it uses the term "generating function" which is a combinatorics term.

@feersum Could you tell me how generating function is in combinatorics?
@Sp3000 Why does this not work? ideone.com/009OMG
I scaled up each term by a factorial

@feersum I don't believe that's correct?

In mathematics, a power series (in one variable) is an infinite series of the form ∑ n = 0 ∞ a n ( x − c ) n = a 0 + a 1 ...

5:59 AM
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.

> 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?

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

Why not?

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

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

6:01 AM
Should I change my question then?

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

@zʏᴀʙiɴ101 I'm here now! :-)

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

@LeakyNun I know.

@wizzwizz4 :D

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.

Yes, since OEIS is heavily combinatorics-focused.

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

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

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

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

6:12 AM
What's the difference between scaling down the coefficients and scaling up the coefficients?

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

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

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

6:26 AM
My rep, it's over 9000!

@Fatalize Félicitations!

@LeakyNun Thanks, you dropped a ´ though

@Fatalize It's 8998?

Lol wtf
as I say that I just lost 30 rep

Oh hahaha

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

oh sorry :p

ಠ_ಠ

It was just a mod 2 challenge

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

ez green points

6:32 AM
Challenge idea: golf a blog.

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

@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

7:05 AM
XAMPP is cool.
I own a lot of ports with me.
>
> Your browser (or proxy) sent a request that this server could not understand.
>
Well, somehow.

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

@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.

Oo.

4K Minecraft videos are what the world needs.

7:14 AM
@HelkaHomba post a challenge! (sorry for randomness)

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

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

@LeakyNun You could make one :P

cool

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:

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

@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 , . /```

@HelkaHomba that's not my keyboard

@orlp I know. But no loopholes :p

@orlp wkr :P

7:27 AM
8
@HelkaHomba that's not my keyboard D:

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

@HelkaHomba People type 100wpm on morse code
(exaggerated)
(maybe not)

@LeakyNun Have we confirmed Sp is people?

0

"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...

I'm making a SUSE Studio appliance.

7:42 AM
1

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...

I need a better name for that than Andrew's openSUSE Leap 42.1, JeOS. :/
O ***, new tag.
Does someone here think that this is a responsible creation of the tag?

We have for one thing

0

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...

8:00 AM
I put together a list of extensions for Stack Exchange
2

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

@zʏᴀʙiɴ101 What does it do?

@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.

"AndrOS"

8:12 AM
Ah, and also Vim.
@Zgarb Heh.

0

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...

Alright, building AndrOS (bo Leap 42.1) now...
bo ==> based on

8:26 AM
Still building...

8:37 AM
Still...

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

@Zgarb Nope, the kernel is already compiled.
It is included into AndrOS as a package.

9:02 AM
Finally finished the build.

Does it work?

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.

@Zgarb

9:17 AM
Yes?

I just posted a new challenge.

:O

0

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...

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

You deserve it :)

9:25 AM
@Quill 0/10 you should look in stackapps under scripts

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

2

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...

@LeakyNun but that's binary

@MᴀʀsUʟᴛᴏʀ A prefix code could be memorized easily.

Morse code is annoying without more unique equipment
@Sp3000 0/10 why emu, not cassowary?

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.

Alright.

@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)

10:08 AM
@MᴀʀsUʟᴛᴏʀ the idea is that they're up to date and it's a curated list

10:34 AM
Guys, should I make another challenge for the real Zgarb function?

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)

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

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)

@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)

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

10:45 AM
Does anyone want the Concaten room?

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

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

@Quill So apparently, he did visit chat. Interesting... writes in notebook
Aaaaah, so much better.

@Sp3000 Alright.

hi all

10:58 AM
hi part of all
37 seconds.

:)
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?

10

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...

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

Alright.

11:29 AM
ok now I have over 9000 rep
no more deletion pls

@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.

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.

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

11:46 AM
ok so.. how about this code-golf challenge. Given a regular expression, generate all possible strings that it can match?

@Lembik what if an infinite number of strings match?
pretty much anything with a + or *

@Fatalize a nice question.. I suppose it should output forever
is that a problem?

18

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...

(related)

3370! :)

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

11:49 AM
@Fatalize as in esolangs?

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

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!

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

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

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

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 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 :)

@Lembik "ppcg" "useful"

@Fatalize well.. see my previous questions :)
@Fatalize there is a lot of talent here .. just needs to be gently directed

@Lembik Lembik secretely getting work done through PPCG challenges

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 :)

@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.

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

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

feel free to steal it from me and make it good

If I only had the time... :/

11:59 AM
I hear you brother/sister

The former.

on the internet everyone is a dog :)
2

@Lembik Meow! (I beg to differ)

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!

1:01 PM
@Zgarb Well then, I apologize for misinterpreting your avatar.
@Sp3000 Alright, after I've understood what it is.

:P good luck

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

minus won not plane crash

you're the first won to spell won right

1:11 PM
@EᴀsᴛᴇʀʟʏIʀᴋ wut

@EᴀsᴛᴇʀʟʏIʀᴋ birds are just biological planes

@AlexA. is this true??

Is there a challenge about "compiling" regexes?

Yes (scroll up - was just talking about that)

Languages are really just a bunch of built-ins.

1:20 PM
¯\_(ツ)_/¯

@LeakyNun That bunch can be larger or smaller.
Compare brainfuck to mathematica

Really, two characters (commands) is the minimum.

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?

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

Are you referring to this challenge?
11

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...

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.

Not sure about full programs though

Hmm

1:51 PM

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

@TimmyD Why are you obsessed with PowerShell?
Where does it come from?

@Fatalize He Powershells for work.

Yep.

hmm

1:59 PM
@LeakyNun You can get by with one. See this:
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...

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

@El'endiaStarman You need the null byte.

@LeakyNun You mean to mark the end of a file? No, you don't.
At least, not on modern systems.

What I had in mind was unary

@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

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.

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

@flawr Heh, early.
17:14 here.

@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.

@El'endiaStarman Kong Yong?

So my sleep schedule shifted to match hers.

2:17 PM
10:15 is not that early though

@zʏᴀʙiɴ101 No, it's 22:17 for me

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

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.

KY = Kentucky right?

@Fatalize Yes.

2:18 PM
What's the standard stereotype about Kentuckians(?)?

musicy?

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

> Unknown Language: Befunge
hahaha

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

@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?=)

2:30 PM
I found a chat bug
Where can I report it?

@Bálint Where?

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

@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.

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

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

2:35 PM
@Bálint browser cache, it's normal to retain the content of the box

does this not happen in other forms for you?

I already cleared my browser history

@Fatalize Bourbon.

history != cache
hard refresh should do

@TimmyD Alcohol, I presume?

2:38 PM
I ckeared the cache and the cookies while clearing history

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...

@MartinEnder No, other inout boxes work as expected

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

2:53 PM
Having fun with EclipseCrossword.
I should have did these in the Sandbox.
Now look in the Sandbox.

### Sandbox

Where you can play with chat features (except flagging) and ch...

3:14 PM

why?

There has been a large Table-Bruteforce-Attack. Unsuccessful, but better be safe.

ftfy

@PhiNotPi Did you ever tell IBM about meta quantum programming?

3:20 PM
@mınxomaτ is there a release or article about the attack

If so, then: github.com/blog/…

thanks

@mınxomaτ @Poke This is why it's good to directly reply to specific messages. :P

yeah will do

3:22 PM
@mınxomaτ yes, but no response

@mınxomaτ Appreciate the warning!

@bkul wat
8 mins ago, by mınxomaτ
damn it

@mınxomaτ What happened to your avatar?

3:34 PM
@flawr Huh?

@mınxomaτ Didn't you have some orange-ish avatar at some point?

A few months ago.
I now have my GitHub avatar: github.com/minxomat

Cool thing, welcome to the animal party of PPCG=)

the codeforces contest is using Kotlin: codeforces.com/blog/entry/45454

@flawr How is Donald Duck not an animal
(my previous avatar)

3:43 PM
@mınxomaτ You had donald duck? I thought you had some orange abstract thing?

No so abstract IMO.

TIL - Donald Duck is abstract and orange.

@mınxomaτ It definitely is orange, but I did actually have a different one in mind.
Sorry =)
Is it really true, that we haven't had a challenge to simply golf the euler totient function?

4429 more rep so I can have an even 10,000 and brag here in chat about it

3:59 PM
@TimmyD Here's a good start.