The Nineteenth Byte

Deadcode

00:38

@DJMcMayhem int f(int a,int b){return(b&-!(b&1))+((b+1)&2)/2^((a-1)&-(a&1))+(a&2)/2;}

Or if they're nonnegative, int f(int a,int b){return(b&-!(b&1))+(b+1)%4/2^((a-1)&-(a&1))+a%4/2;}

int f(int a,int b){return(b%2?0:b)+((b+1)&2)/2^(a%2?a-1:0)+(a&2)/2;}
int f(int a,int b){return(b%2?0:b)+(b+1)%4/2^(a%2?a-1:0)+a%4/2;} // nonnegative only

@Veskah path-of-the-wildebeest-where-trapped_v2.svg - I transposed x and y

Veskah

@Deadcode Noice

Quintec

01:02

I can't find the dot lol

Deadcode

Top middle :)

Quintec

It took me until 300% zoom to see that orange thing

Deadcode

You can edit the source to make it larger... change the value of r in <circle cx="192" cy="8" r="0.125" fill="red"/>

Deadcode

01:18

int f(int a,int b){return(b%2?0:b)+b*3/2%2^(a%2?a-1:0)+a%4/2;} // nonnegative only

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

Solve the Catalan Conjecture! Let's say we have a number n, if it's even n = 2*n and if it's odd n = 3*n+1 For example: 10 -> 5 -> 16 -> 8 -> 4 -> 2 -> 1 you stop when you reach one because it will loop forever after that: 1 -> 4 -> 2 -> 1 Input any natural number. Your code can be a f...

lirtosiast

02:01

@Deadcode The yarn on a 3x3 cube starts at the center, spirals around the top face, then spirals across the outer faces down to the bottom face, until it reaches (0,0,-1), then goes to (0,0,-2)

Deadcode

Okay. I considered that too.

But it's much less like a ball of yarn.

lirtosiast

True

I don't really know what to call it

Deadcode

02:32

@lirtosiast Would it be acceptable if it covered faces using a back-and-forth snake pattern instead of a spiral? Its Chebyshev distance would still be nondecreasing.

New Meta Posts

03:36

0

Q: If there is "a winner for every language" in a code golf challenge, does competitiveness matter?

The consistent attitude with regard to the golf language situation is that for every challenge, each language is a category, and subsequently there is a 'winner' for each language. This is also a very very popular opinion with regard to the new user experience. There is a problem with this idea...

Veskah

Aw yeah, Participation Ribbons, boyos

MilkyWay90

04:25

I suddenly just got +100 reputation for an association bonus

What is an association bonus?

Veskah

Basically you haven't been a rude dude so you get to bypass the need to grind rep for basic features on new SEs

Like commenting needs either 50 or 75 rep, I forget which

Anonymous

375

Q: What is the association bonus?

I was just awarded +100 reputation on all of my Stack Exchange accounts. What is this bonus for? It simply says "Association Bonus" on my reputation overview. Return to FAQ index

support faq association-bonus association

Anonymous

TL;DR: when you reach 200 rep on any site on the network, all your accounts on all sites get +100, because reaching 200 rep is a decent sign that you know enough about how SE works to not need the training wheels of <100 rep on any site

MilkyWay90

04:47

@Mego Oh okay, thanks!

New Sandboxed Posts

05:42

0

A: Sandbox for Proposed Challenges

Super Permutations Find the super permutation for a set of size n. A super permutation of a set is one string that contains all permutations of that set. Here is a helpful video by Matt Parker Example For a set of size 2 all the permutations are AB, BA but the super permutation is ABA because ...

lirtosiast

@Deadcode Of course. There are other solutions too, and I want part of the challenge to find the golfiest one.

New Main Posts

08:27

-2

Q: Earphone disabler

Write a simple python script that plays the system sound from windows speaker even if earphones are connected. For example, you should be able to play music from windows speaker and should be heard by someone who is not wearing the earphones connected. This should disable the earphone functional...

code-golf kolmogorov-complexity python windows-system

New Meta Posts

09:34

0

Q: Remove [windows-system] tag

windows-system was just created for a question put on hold as unclear, and I see no reason to have OS-specific tags. Indeed there are none for any other OSs.

discussion feature-request support tags

Anush

11:12

hi all

Adám

@Anush Hello.

Anush

11:25

I was thinking of a challenge where you have to say the number of moves to mate for any 3 piece chess endgame

or output that it's not a forced mate

does that sound reasonable?

I suppose it has to be a restricted time code-golf challenge to make any sense

primo

do you personally know of a good way to solve this problem, without brute forcing?

Anush

@primo The challenge is not really to find out the answers, which I think is easy, but to encode them in small space

three pieces is just two kings plus one other piece

primo

oh, i was thinking 3 pieces per player

Anush

@primo that's much harder!

those databases exist and it would be great to be able to encode them in less space

but not as a first challenge :)

primo

i think the problem should be simple enough that even brute force should be viable

Anush

11:37

there is a challenge where the point is for the code to find the answer

there is another challenge, the one I had in mnid, where the answers are precomputed and the challenge is to make the code including the answers as small as possible

a code-golf challenge

primo

queue=[{state = <input>, depth = 0}]
while queue not empty:
  state, depth = queue.next()
  if state is checkmate: print(depth) and exit()
  foreach move in validmoves():
    newstate = state.apply(move)
    queue.add({newstate, depth+1})

i think that could be made fairly short

Anush

yes that's the first challenge.. but not the one I wanted :)

both would be good in fact

New Main Posts

12:14

-2

Q: How to measure the normalized correlation coefficient between two 3d objects using their vertices, on Mathematica?

I tried using the function "Correlation" on mathematica but it says that it measure Pearson's correlation coefficient: Correlation[Flatten[Vertices1], Flatten[Vertices2]] where Vertices1 and Vertices2 are vectors of the vertices of the two 3D objects.

math

J. Sallé

13:15

The most recent wave of fake news spread through facebook and messaging apps have forced the Brazilian Intelligence Agency to publish a note telling people that they did not, in fact, arrest venezuelan and cuban terrorists for sabotaging the recently ruptured dam in MG.

I mean people are so desperate to blame everything on the left that they just spread this kind of misinformation and get people killed because of it.

Sorry for the political rant in TNB but goddamn does that make me mad.

New Sandboxed Posts

13:33

0

A: Sandbox for Proposed Challenges

Binary UTF-8 quine quine code-golf kolmogorov-complexity Your task, if you wish to accept it, is to write a program that outputs its own source code in the binary UTF-8 representation. Rules You must build a full program. That is, your output has to be printed to STDOUT. The source must be ...

New Main Posts

14:58

0

Q: There's a hole in the bottom of the sea

Whilst trying (and failing) have persuade my infant son to eat his dinner, I tried singing to him. Mid way through this song I realised the formulaic structure might lend itself well to code golfing! The task is to write a program or function which accepts no input and produces the following tex...

code-golf kolmogorov-complexity

mınxomaτ

@Dennis You're a fedora expert, right?

Dennis

15:21

I use it for TIO. Not sure if that makes me an expert...

Adám

16:19

Is the following best suited for CMC or main? Given two arrays recursively consisting of strings and such arrays, determine if they are "compatible". Compatibility is defined as having the same structure and all corresponding strings have the same length (though the content may differ. E.g. ["abc",["ab","de"] and ["azz",["ab","xy"] are compatible while ["abc",["ab","de"] and ["az",["ab","xy"] are not.

Maybe even more interesting to allow numeric values too?

flawr

17:00

@Doorknob I found your family album: instagram.com/knoblox

Erik the Outgolfer

and this is where I shamelessly say that they're all prettier than our Doorknob...

AdmBorkBork

Including the chicken-head one.

Erik the Outgolfer

well, except the bulldog-headed one

Deadcode

Aww, they're a doorbell.

5

flawr

17:18

@Deadcode I got your pun within the first few seconds, I'm proud of myself:)

Deadcode

I haven't used it for 20+ years :) and suddenly this opportunity comes up!

AdmBorkBork

19:13

CMC - code-golf Implement Jelly's X feature. "Choose a random item from z if z is a list, or from 1 to z inclusive if z is a positive integer. If z = 0, return z. Error if z is negative or a decimal." No peeking at Jelly source code.

Erik the Outgolfer

> No peeking at Jelly source code.

lol why?

AdmBorkBork

Well, you could just copy-paste it and that's dumb.

Erik the Outgolfer

but it's not golfed anyway

also, the "no peeking" part truly comes from you, not from the spec :P

AdmBorkBork

Are you saying Dennis didn't golf the Jelly source code? I ... that is ... brain explode

True

Erik the Outgolfer

well, I have seen the source code... it's awful in some ways, but definitely not golfed, others (including me) have also contributed to it...

AdmBorkBork

19:21

I have 72 bytes in PowerShell Try it online!

Erik the Outgolfer

also, you haven't really described X completely apart from copying it from the wiki... what should it do when given a single character? (A: it should error)

AdmBorkBork

@EriktheOutgolfer That's neat. I had thought it was a one-man job. I didn't realize it was a community effort.

Erik the Outgolfer

um, everything can be a community effort, that's the entire point of OSS :P

AdmBorkBork

Yeah, but just because it is OSS doesn't necessarily mean that multiple people have contributed to it.

Erik the Outgolfer

although Dennis himself has set some principles

no, it means they're able to contribute, and, well, unless the repo's owner has some sort of problem, they'll most likely welcome or amend your contributions

of course, that's not always the case with private repos

in fact, a very important reform in Jelly's history was done in part by dylnan

Adám

19:36

@AdmBorkBork APL (Dyalog Unicode), 19 bytes {⌊⊃∘⍵⍣(≢⍴⍵)?⊃⍵,⍨⍴⍵}

AdmBorkBork

Neat error.

Deadcode

Step 1023461556224: Position 1022773981816 (max: 1081064466347); pruned to 910176625888 - wilderabeest (1,2 + 1,3 + 1,4) still chugging along.

Pavel

@AdmBorkBork Perl, sub f($z){ref $z?$z->[int rand@$z]:int rand$z} takes either an int or an array reference

Deadcode

wilderebeest (1,2 + 1,3 + 2,3) goes at least beyond Step 149213413376, but didn't have enough RAM to continue.

Pavel

@Pavel nvm doesn't have the <=0 behaviour

Perl is pretty bad at this whole "list or int" idea

It can't differentiate between an int and a one-element list

Adám

19:54

@AdmBorkBork Yeah, lately, we've been adding more human friendly error messages. I particularly like when it pinpoints the exact problematic item.

Pavel

At least it's better than GCC

AdmBorkBork

> An error occurred.

Pavel

tio.run/##K0gtyjH9/z8tP18hKbHo/38A

AdmBorkBork

20:13

Nice. PowerShell has ... verbose, let's call it ... error messages. The challenge from a while back had PowerShell I think in the lead for longest error. I mean, even things like ARNOLD C and Shakespeare were easily beating it.

Pavel

@AdmBorkBork template errors tho

AdmBorkBork

Yeah, that's true. There's a lot of generic boilerplate on the error messages.

Brr is it frickin' cold here today.

The high today is -15F / -26C ... and that's without windchill.

DJMcMayhem

That's what you get for deciding to live in Antarctica

AdmBorkBork

Actually it's about the same as the Amundsen-Scott station.

So, there's that.

DJMcMayhem

20:28

Did you think I was kidding? xP

AdmBorkBork

No, I suppose not. But I'm not a penguin, either.

Poke

it was like 27F this morning

so chilly :]

thank goodness it has warmed up to 30F

ignoring the snow squall warning everyone in the office just got on their phones

WE COULD GET UP TO 1 INCH OF SNOW

better make a NWS alert!

AdmBorkBork

Well, if you only have one snowplow per county ...

Poke

this whole state is afraid of snow

DJMcMayhem

Which state?

Poke

20:38

CT

been here for almost 4 years and every year people tell me that we get a lot of snow... I've lived in Ohio and New York. CT doesn't get shit for snow

I don't think I've seen more than 4 inches

AdmBorkBork

lol

@Poke Also, out of context quote of the day.

Poke

;)

oh there's another alert

this is definitely a good use of the national warning service

national weather service?

whatever

AdmBorkBork

Yeah, National Weather Service

Adám

@Pavel tio.run/##SyzI0U2pTMzJT/8PBGn5@QpJiUUA

Quintec

21:13

@Poke Ohio currently has gotten like 2 inches of snow total this winter

Poke

@Quintec Not northeastern ohio

trichoplax

21:39

@lirtosiast I like that. Even better than a challenge for a specific spiral. Looking forward to seeing what approaches emerge. Also looking forward to the follow up challenges using one of the spirals provided to set more extensions of the trapped knight / wildebeest challenges

Erik the Outgolfer

3D chessboard? :P

Pavel

21:58

is anyone here a git wizard

trichoplax

@EriktheOutgolfer Yes I've been wondering what the moves would be. The knight's move in 2d can be described as any square at a distance of the square root of 5 from the current square, so maybe that kind of description would be the easiest way to unambiguously describe the moves of a piece that moves in 3d

@Pavel I'm not a wizard, but I can Google

What needs knowing?

Erik the Outgolfer

@trichoplax or simply one step in one direction and two in another lol

Pavel

how does sparse checkout work

I've followed all the directions and it's not doing the thing

trichoplax

@EriktheOutgolfer Fair enough

Pavel

oh nvm i'm an idiot

actually

no it still doesn't work

trichoplax

22:02

Are you trying to do this:

141

Q: Is it possible to do a sparse checkout without checking out the whole repository first?

I'm working with a repository with a very large number of files that takes hours to checkout. I'm looking into the possibility of whether Git would work well with this kind of repository now that it supports sparse checkouts but every example that I can find does the following: git clone <path> ...

git

Pavel

@trichoplax No I was an idiot and typo'd sparse-checkout

only 10 minutes of my life lost

trichoplax

10 minutes is pretty good going :)

Pavel

yep

New Meta Posts

22:19

0

Q: Do you think artificial intelligence is watching us on Code Golf and laughing at us?

The AI is is reading Code Golf and thinking, "hahaha not even close to the most efficient, suckers!!", "It took you that long to figure out how to get it down to one byte? hahaha" Do you think the AI is doing that?