The Nineteenth Byte

6:00 AM

You should try to find some different one-line programs before beginning the search for ^...\n> [program]

Anonymous

@feersum It's an advantage because the amortized time across all inputs is much better than incrementally. If the correct seed is 2^32-2, for example, the incremental version will require 2^32-2 iterations before it finds it. With randomly-generated seeds, on average, it will take 2^31 iterations for any input.

El'endia Starman

Is it, though? What if the correct seed is 2?

Doorknob

1000x1000 animation in progress...

(82/100 frames)

feersum

Any code that only searches 500 million programs in 18 hours must be very slow, so whatever.

Anonymous

@El'endiaStarman That would take even longer than just exhausting the seed space, since I would have to chain-run an interpreter.

Anonymous

6:02 AM

And solve the halting problem

El'endia Starman

Stop it after 1 second, say.

If it produces more than 3 1s in that time, you're probably good.

Anonymous

@El'endiaStarman It is drastically more likely that the correct seed is in the range [2^31,2^32), meaning that randomly choosing seeds will be faster on average for most seeds

El'endia Starman

true

New Main Posts

0

Q: Let's Make Music!

Lots of people like to play music for fun and entertainment. Unfortunately, music is pretty difficult sometimes. That is why you're here! Task It's your job to make reading music much easier for those struggling with it. You need to write a program or function that takes as input a musical staf...

Anonymous

Consider this: there is an equal probability that the seed is in [0,2^31) compared to [2^31,2^32)

feersum

6:04 AM

How is that range better than [0, 2^31]?

El'endia Starman

@NewMainPosts That's not a duplicate?

Anonymous

Because, on average, it will take 2^31 iterations to choose a number in [0,2^32) when choosing randomly

feersum

The same's true whatever order you do it in.

Anonymous

Where it would take n iterations iteratively to reach n

feersum

That doesn't change your expected time for the search.

And solutions with a low seed are golfier, so you should try them first.

Anonymous

6:06 AM

...yeah that's actually right, it comes out the same across all inputs

Anonymous

It makes me feel better, then :P

El'endia Starman

@feersum ...what? How do low seeds make shorter programs?

Anonymous

And low seeds are golfier, but there is no guarantee that a 32-bit seed exists that will spit out this program

Anonymous

@El'endiaStarman 7 2 is shorter than 7 245276612

feersum

@El'endiaStarman The source code is a seed and a length iirc

El'endia Starman

6:08 AM

I think finding a Seed program is a great enough achievement that trying to golf it won't help. :P

Calvin's Hobbies

What challenge is this for? Does it relate to the colorful smoke fractals @Doorknob was posting?

Anonymous

The fact that I got 4 characters correct in under a quarter of the seed space is reassuring though

El'endia Starman

@Calvin'sHobbies Truth Machine.

Anonymous

It means the odds aren't totally against me

feersum

@Mego You should not be reassured by that.

Since finding more is exponentially harder.

Anonymous

6:09 AM

@feersum shush stop making me feel bad with math

Anonymous

I should put this version of the seed-finding program on Github

Anonymous

It also outputs the current # of seeds tried, to make keeping track of the progress easier

El'endia Starman

Y'know, I like the idea of just generating characters in a stream (after getting a ^) until you get \n>....

quartata

While @Mego has his Seed program in the oven I'm baking a Malbolge program

El'endia Starman

That's pretty much near-guaranteed to produce an appropriate program eventually.

quartata

6:13 AM

What does it do? ... you'll see

(if it ever finishes)

Anonymous

@quartata Good luck with that

Anonymous

If someone finds a Malbolge program for Truth Machine, you can have all of my rep

quartata

@Mego That wouldn't be so bad probably.

Anonymous

And by all I mean like 200

quartata

This is just for a kolmogorov complexity challenge.

Anonymous

6:16 AM

I know there's a decent bounty for a HW Seed program, but it's almost surely non-existant

Anonymous

Due to the 2^32 seed space

feersum

It's surely existent, but impossible to actually test.

Calvin's Hobbies

Mini-math challenge: At what height would you have to draw a horizontal line in a unit semicircle such that the top and bottom portions have the same area?

feersum

The only way to find it is if you could mathematically find a way to search for a certain sequence in the Mersenne twister's byte stream.

And it would probably be so large that you could not actually generate those bytes.

quartata

This will probably finish in a hour or two

Anonymous

6:18 AM

@El'endiaStarman The issue also with this suggestion is that you don't know how many bytes to take

quartata

But I'm too sleepy to wait around for it

Doorknob

imgur hates me for trying to upload huge GIFs, so I'm putting it on my webserver :P

phase

If you ever have free time, this is my favorite thing to search on GitHub

feersum

Circle area integral is really long and gross iirc

mınxomaτ

@Doorknob I recommend imgup.

El'endia Starman

6:21 AM

@Mego Doesn't matter. Just keep producing characters.

Doorknob

(that one was disappointing considering it took so long. I'm trying to get multithreading working now)

quartata

@phase Hey, Hexagony is on that list

I had no idea Hexagony was written in Mathematica

El'endia Starman

What? I thought Martin wrote it in Ruby...

quartata

He did.

But not according to GitHub.

El'endia Starman

...weird.

TanMath

6:24 AM

@quartata so you at least went through 5 of the pages?

quartata

@TanMath Yes.

El'endia Starman

@Doorknob That's a huge file.

quartata

It is on page 7.

I was mostly looking for my own language on account of me being a narcissist

Doorknob

@El'endiaStarman yeah...

Anonymous

@Calvin'sHobbies h such that int [0,1] int[0,pi] r dthetha dr - int [0,1] h dx == 0.25

phase

6:25 AM

This guy doesn't understand git push origin master

El'endia Starman

@Doorknob Finally loaded fully and wow, that's pretty.

quartata

Hey, supercollider is on that list too!

El'endia Starman

Though...yeah, not as impressive for the amount of effort/time that went into it...

quartata

So many languages I know that aren't mine

Anonymous

I cba to open up sage and calculate the answer

quartata

6:26 AM

I saw Scala too

TanMath

@quartata it says half of it was ruby, and the other half is mathematica...

feersum

@Mego You can't use polar coordinates to integrate over a rectangle.

Doorknob

@El'endiaStarman I think it's just bad luck with the random numbers :P

that's why I'm multithreading, so I can try more combinations

quartata

@TanMath The only thing in Mathematica was the plotting I think

Anonymous

Messed up my solution

Anonymous

6:29 AM

h such that int [0,1] int[0,pi] (r-hsin(theta)) dthetha dr == 0.25*pi

TanMath

@quartata yes, but the fact that it is 600-700 lines makes it seem half of the coding is Mathematica...

Anonymous

@feersum You're right, but I can use polar coordinates to integrate over a circle and subtract out the area of a rectangle

quartata

@TanMath lol

Anonymous

Oh crap

feersum

@Mego I would be really shocked if that formula worked.

TanMath

6:30 AM

@quartata see? I cracked the case!

Anonymous

That should work better

Anonymous

Works better to convert it all to polar and combine them

Alex A.

@Doorknob You should be combithreading, so you can try more multinations.

Anonymous

Crap my conversion is wrong

quartata

Oh I'm stupid.

I didn't understand how the fixed-length BOR generator worked.

phase

6:33 AM

Hexagony is written in Ruby

quartata

Whatever. I'm not doing that for all n

Poorly golfed program coming up

feersum

@Mego What you want is h such that int[0,h] sqrt(1-x^2) dx = pi/4.

Doorknob

19892 llama     20   0   42412  37212   2020 R 100.0  0.6   0:24.64 fractal
19883 llama     20   0   54160  49032   2104 R  99.0  0.8   0:29.19 fractal
19890 llama     20   0   54160  49000   2068 R  98.7  0.8   0:26.55 fractal
19885 llama     20   0   54160  49124   2192 R  93.0  0.8   0:27.16 fractal

who cares about multithreading :P

(I decided to run four instances in parallel to produce four animations at once. The numbers in the fourth-to-last column are CPU usage.)

Alex A.

:O

El'endia Starman

wow

Alex A.

6:37 AM

Hope you didn't have anything else you needed to do while it was running. :P

quartata

0

A: We're no strangers to code golf, you know the rules, and so do I

Malbolge, 12735 bytes D'`N^?o!6}{FW1gSSR2PO)oo98[H('3}C#"?xwO*)L[Zp6WVlqpih.lkjihgI&^F\a`Y^W{[ZYX:Pt7SRQPOHGkK-CHA@d>C<;:9>=6Z:9876v43,+Op.',%*#G'&}$#"y?}_uts9qvo5sUTpong-NMib(fedFEa`_X|\[T<RQVOsSRQP2HlLKJCgAFE>=aA@">76;:9870Tu-2+*)Mn,+*#"!Efe{z!x>|utyxwpo5Vlqpih.fed*ba`&^c\[`Y}@\[TSXQuUTMLQPOHl...

Calvin's Hobbies

@feersum yep

quartata

Probably suboptimal.

Anonymous

1/4*sqrt(-pi^2 + 16)

El'endia Starman

@quartata WHUT.

quartata

6:38 AM

@El'endiaStarman Basically.

I could have made it better if I wanted to spend a week generating it

Anonymous

Or approximately phi-1

quartata

And yes it actually works.

feersum

@quartata Did you write the generator yourself or did you find one?

quartata

@feersum Found one and fiddled a bit with it

Everyone thinks Malbolge is so scary but it's a pretty easy to understand language

feersum

If you generated it using someone else's program you should credit that in your answer.

quartata

6:40 AM

It's just... misunderstood

Anonymous

600 million seeds and counting

Anonymous

We'll see where it is in the morning

Anonymous

Night all

TanMath

@quartata just looking at the hello wrold code in the wikipedia page makes me feel intimidated!

Doorknob

well this is taking a while

quartata

6:42 AM

@feersum done

don't kill me please for using a generator I couldn't have done it by hand

feersum

You could have at least made a golfing generator :P

quartata

@feersum so picky

I did spend some effort on this

Doorknob

I like the consistent usage of 95%-100% CPU on all 4 cores... it makes typing in this textbox a wonderful experience

4

quartata

@Doorknob fractals are fun aren't they

Alex A.

Get more cores

Calvin's Hobbies

6:44 AM

get 7 more

Doorknob

so each of the 4 animations are at around frame 60

Alex A.

@Calvin'sHobbies Dude 11 cores would be sick

El'endia Starman

Okay, running the streaming Seed brute-forcer now.

quartata

@AlexA. -1 Not a multiple of two

Calvin's Hobbies

Prime core counts are optimal due to Fibonacci sub-sequencing

El'endia Starman

6:47 AM

It's got the first three needed characters so far out of 9.

Alex A.

@Calvin'sHobbies I don't know what this means but it sounds mathy enough to be correct.

feersum

Selling processors in non-power-of-2 multiples is a great business opportunity.

People would be really struck by the novelty of it.

Alex A.

It's true. I believe they would sell like hotcakes.

quartata

9

Q: Unique Sudoku Finder

Challenge: Given a Sudoku board on standard input, find the minimum number of numbers added to make the board unique. Specifics/Rules: The input is formatted as follows (all whitespace is significant) 516|827|943 278|394|615 349|615|872 ---+---+--- 98 |4 2|156 465|189|237 12 |5 6|489 ---+---...

code-golf game sudoku

This challenge is 4 years old and has no answers

@AlexA. mmm hotcakes

Calvin's Hobbies

@AlexA. Just think about the proto-bayesian between neighboring cores. The corresponding Ruth-Gellar module shows that primes are optimal.

quartata

6:51 AM

@Calvin'sHobbies dilbert.com/strip/2009-05-18

Alex A.

@Calvin'sHobbies Here's my money give me the cores

@quartata Who the hell calls pancakes "hotcakes"?

quartata

@AlexA. People who don't make their pancakes in pans.

Alex A.

They make them in... hot?

quartata

Over an open fire.

Alex A.

Savages

Calvin's Hobbies

6:52 AM

Flat circular cakes are hot more often that they are in pans.

quartata

jackfrosstttt nipping at your nose

Wow no one got the reference.

Alex A.

@Calvin'sHobbies Idk, mine get cold pretty quickly after removing them from the pan.

@quartata Correct

quartata

Just noticed that the last example that was "for good luck" on this: codegolf.stackexchange.com/q/63290/45151 is the SMB theme

Also just found this:

6

A: Average of a string

Julia, 41 bytes With help from @AlexA. a->Char(round(Int,mean([Int(i)for i=a]))) (Older version only worked in Julia 0.3.)

Very suspicious

Calvin's Hobbies

@AlexA. I mean pancakes is a subset of hotcakes

Alex A.

I don't think that's true

Calvin's Hobbies

6:55 AM

And both are subsets of primecakes

Alex A.

By Wilson's Theorem for Primecakes, one should eat a lot of cakes.

El'endia Starman

Nothing better than 3 characters out of the first 103,983,757 for the seed 153.

Alex A.

@quartata It had a bunch of back and forth between ಠ_ಠ and me in comments that I nuked. I provided the 0.4 solution. I wouldn't post a 0.3 solution because I don't have it anymore; I upgraded.

quartata

@AlexA. Suspicious

Alex A.

Ok

You may suspect as much as you'd like

But it isn't true

quartata

6:58 AM

Methinks he does protest too much

Calvin's Hobbies

@AlexA. Precisely. (assuming Marshmallow-Francake et theory)

Alex A.

Medoesn't giveth a shit

Doorknob

the four GIFs are done but they're huge

Alex A.

@Calvin'sHobbies Btw, "hotcakes" gets redirected to "pancakes" on Wikipedia.

quartata

Methinks he does giveth a shit

Alex A.

6:59 AM

Youthinks mine shit hath been given?

Calvin's Hobbies

@AlexA. Maybe on your computer

Alex A.

Oh right, I have a different version of Wikipedia installed.

6

Calvin's Hobbies

Somebody scammed you. They sold you the version where all instances of hot were changed to pan

quartata

@AlexA. Methinks you hath

M̭̠̰̟̦ę̝̬t̢̺͕͚̥̣̜h̪͖̮̠̗͡i̠n̰͉͕͓k̘̱̹̭͙s

Alien G

It hurts. The failure.

Alex A.

7:05 AM

Now that's a big dosa

quartata

What inspired you to make World Big Dosa anyways

Alex A.

The video linked in the challenge

quartata

I can't believe no one made a Chef answer for that

I gotta fix that

Alex A.

Somebody tried. He only got part way through (it's an overcomplicated challenge) and the code was already too long to fit in a post.

quartata

@AlexA. Seriously?

Hmm.

Maybe I'll have better luck...?

I really want to try for some reason.

Alex A.

7:07 AM

Worth a try if you're that bored.

Doorknob

keyboardfire.com/fractalflames/out1.gif <>

4

that one finally finished uploading

quartata

> Occasionally grudgingly use Java / PHP, only when necessary

ಠ_ಠ

> Always (never grudgingly) use Java / PHP, even when not necessary. All hail Java and PHP

FTFY

Alex A.

@quartata It should be: "Occasionally begrudgingly use Java. Never, under any circumstances use PHP."

quartata

PHP and Perl are what keep the internet together stop hating on them

Alex A.

Can't stop how I feel

quartata

7:11 AM

@Doorknob This finally finished loading for me. Impressive!

Doorknob

keyboardfire.com/fractalflames/out2.gif <>

Alex A.

While that's loading, I'll just add this:

Calvin's Hobbies

@AlexA. Fascinating

Alex A.

I want one

phase

@Doorknob your gifs are killing my browser ;-;

quartata

7:13 AM

@Calvin'sHobbies Fascinating, Captain

FTFY

Doorknob

@phase sorry! I won't onebox the next two :P

I'll unonebox these as well

Calvin's Hobbies

@AlexA. Can we get one of those for the minecraft server?

Alex A.

Are there pancakes in Minecraft?

I wonder if we could make an automatic cake maker.

quartata

@AlexA. No

@AlexA. No automatic crafting so no

Calvin's Hobbies

Time to call in a favor from Notch

Alex A.

7:15 AM

Notch no longer works for Mojang

quartata

You can make all the ingredients

@Calvin'sHobbies He's too busy enjoying his ouzo jacuzzi

Calvin's Hobbies

Not really: The melancholy billionaire: Minecraft creator unhappy with his sudden wealth

Doorknob

keyboardfire.com/fractalflames/out3.gif <>

haha these take forever to load

quartata

Twas a joke

Anywho I better be off. bai

Alex A.

bai

Doorknob

7:21 AM

keyboardfire.com/fractalflames/out4.gif <>

Alex A.

Beer bread

Beer bread can be a simple quick bread or a yeast bread flavored with beer. Both beer and bread have a common creation process: yeast is used to turn sugars into carbon dioxide and alcohol. In the case of bread a great percentage of the alcohol evaporates during the baking process. Beer bread can be made with simply flour, beer, and sugar. Some bottled beers, especially craft beers may intentionally have visible live, but dormant, yeast sediment at the bottom of the bottle. However, many mass market beers have the live yeast filtered out. Without sufficient leavening from the beer, a loaf of beer...

Why didn't I know this exists.

phase

It's okay, not the best @AlexA.

Alex A.

Oh you've had it?

phase

Yeah, one Thanksgiving years ago @AlexA.

Alex A.

:(

Optimizer

7:49 AM

btw, how did @AlexA. help @ಠ_ಠ in the average string challenge without even interactibg once?

Alex A.

We interacted in the comments. I mod deleted them since they were obsolete.

Calvin's Hobbies

aka incriminating

Optimizer

lies

all lies

Calvin's Hobbies

Allies?

Optimizer

yes

exactly

revelation

Calvin's Hobbies

7:54 AM

@ಠ_ಠ Would you like to join the PPCG Minecraft server?

Κριτικσι Λίθος

I bet @ಠ_ಠ will live in @AlexA. 's house :P

Alex A.

My Minecraft house is too small for two.

@Calvin'sHobbies I actually don't know whether ಠ_ಠ's parent user plays Minecraft. It would be fun to have them if they do.

Calvin's Hobbies

Hmm, why did VTC just join the room as I said that.

Alex A.

Suspicious

VoteToಠ_ಠ

Calvin's Hobbies

But no Octave or Julia answers

Κριτικσι Λίθος

7:59 AM

@Calvin'sHobbies Juila

Nobody said "Juila"

Jiual

Juail

map(join, permutations("Julia"))

That's Julia code

Returns a 120-element array

Calvin's Hobbies

:M

Alex A.

8:04 AM

:∑

Alien G

Why isn't this a Skype group, if I may ask?

Alex A.

I don't think it's been suggested. We have a very inactive IRC channel: ##ppcg.

Calvin's Hobbies

Not everyone has or wants other accounts.

Alex A.

^

And I don't think anyone wants to see anyone else's face.

Κριτικσι Λίθος

This is how I look like.

Calvin's Hobbies

8:08 AM

Rather, no one wants anyone else to see their face.

Alex A.

Rather, none of us have faces.

Optimizer

if we are a skype group, we can solve the mystery of @ಠ_ಠ

Calvin's Hobbies

(Alex is just a bird wearing a sock anyhow)

Optimizer

yes ^

Alex A.

@Calvin'sHobbies Birds don't wear socks

Calvin's Hobbies

8:10 AM

@AlexA. Birds do

Optimizer

V they do

ಠ_ಠ, σ_σ

331 7

code-golf string kolmogorov-complexity math

Alex A.

@Calvin'sHobbies Birds != Birds?

©_©

¿Hola?

Okay bye

Optimizer

ok, ok, I come out. @ಠ_ಠ is my sock.

And now that its revealed, please feel free to delete that account

Κριτικσι Λίθος

Bye @ಠ_ಠ

Optimizer

GN @ಠ_ಠ

Calvin's Hobbies

8:15 AM

Bye_Bye Birdie

Κριτικσι Λίθος

ಠ____________________________________________________________________ಠ

Alien G

@AlexA. I don't have my face set as my skype pic... Is that normal?

Calvin's Hobbies

Why use skype except for video (or at least audio) chat?

Κριτικσι Λίθος

8:31 AM

"Skype".split("").reverse().join("").toLowerCase() === "epyks"

randomra

@feersum created our 4th most common comment with This does not work correctly for the input falstrue. Just overtaking How does it work?. (data.stackexchange.com/codegolf/query/edit/387070)

Optimizer

from now on, I am gonna treat @ಠ_ಠ as @AlexA. itself wherever possible.

Calvin's Hobbies

@ΚριτικσιΛίθος Why split and join?

Κριτικσι Λίθος

404

A: How do you reverse a string in place in JavaScript?

function reverse(s){ return s.split("").reverse().join(""); } Caveats : http://stackoverflow.com/a/16776621/1636522.

Optimizer

[..."Skype"].reverse().join("")

also, there is literally no real in place in JavaScript :P

Κριτικσι Λίθος

8:41 AM

@Optimizer What are the "..."?

Optimizer

What are the what?

can you please complete your question?

Κριτικσι Λίθος

What does the ellipsis do?

Optimizer

:D :P

ES6 spread operator

look up

feersum

9:19 AM

@randomra lol!

Lembik

9:36 AM

hi

is code to solve chess puzzles on topic or is just coding the different piece moves too much effort for PPCG?

phase

There might already be a chess problem out there @Lembik

Lembik

I have seen some

to be precise, I want to pose a challenge that asks for the maximum number of pieces for black for which there is a mate in X for white

given the normal starting positions of all the pieces

but it involves coding some sort of chess engine

which might be hard to do in very short code

randomra

9:54 AM

@Lembik would that be a golf or challenge problem?

New Meta Posts

10:08 AM

0

Q: Multiple functions used for solving a question?

If your solution for a question requires, say, two functions, that should be called one after another, is it acceptable to define the two functions, with it being expected that the user will invoke the two in sequence? That is, if you define two functions f(x) and g(x), with the intention being ...