The Nineteenth Byte

code-golf cops-and-robbers Will it halt? Cops: This is the cops' thread. The robbers' thread is here. Your challenge is to make a program that runs forever without halting1, unless it gets a particular input2. If it receives that input, it must terminate in a finite amount of time3. This is c...

totallyhuman

Is my new description of meanders clearer?

MD XF

@HyperNeutrino I obviously can't ping your old account, but you commented on this, so do you want to take a look? I improved it significantly

0

A: Sandbox for Proposed Challenges

Cubify text code-challenge esolang Your challenge is to translate ASCII text into Cubically source code. Cubically is a programming language I wrote a while ago. It contains two pieces of memory, a 3x3 Rubik's Cube and a register called the "notepad". Cube The internal Rubik's Cube is initial...

(it better be good 'cause I just spent an hour on that script, I've never done that much bash before)

HyperNeutrino

You'll need to keep the 100 strings consistent between testing answers obviously but otherwise I like it :)

MD XF

Yep the 100 strings are pseudorandom, meaning that they are not seeded, so they'll look random but be the same every time. Thanks

HyperNeutrino

Also, import random;print('\n'.join([''.join(chr(random.randint(97,122))for i in[0]*100)for j in[0]*1000]))

MD XF

1:23 AM

I bet the actual challenge, when I post it, will get like two upvotes and zero answers, 'cause nobody cares about the hard (and this is extremely hard) challenges... ಠ_ಠ

@HyperNeutrino I don't speak snake

HyperNeutrino

lol

MD XF

All I saw was import hiss;hissssssssssssssssPythonSucksssssssssssssssssssssssss

HyperNeutrino

>.<

MD XF

:P

@else does this look good?

HyperNeutrino

SyntaxError: else block declared without if block

MD XF

1:30 AM

That's not on my script, is it?

HyperNeutrino

No that's because you said @else without @if :P

hehe

MD XF

ಠ_ಠ is this payback for disliking Python

HyperNeutrino

maybe :)

MD XF

Wait a sec... what language uses @else and @if for control flow?

HyperNeutrino

Nothing :)

totallyhuman

1:35 AM

for p in permutations(range(n)):z=[*zip((-1,)+p,p+(n,))];c+=all((x<a<y)==(x<b<y)for i,(a,b)in enumerate(z)for(x,y)in map(sorted,z[i%2:i:2]))

what is this even

HyperNeutrino

death

ATaco

CMC: Write cov followed by infinite fes, without anything in between.

HyperNeutrino

VTC as impossible

totallyhuman

can it be a generator function

ATaco

It can.

@HyperNeutrino No.

totallyhuman

1:36 AM

@HyperNeutrino vtc your vtc as invalid close reason

HyperNeutrino

f=lambda x="cov":f(x+"fe");print(f())

or I guess that's invalid

ATaco

That never returns, so technically invalid.

DJMcMayhem

@ATaco V, 9 bytes: icov<ESC>òAfe

totallyhuman

def c():
 yield'cov'
 while 1:yield'fe'

HyperNeutrino

def f(x=1):print('cov'if x else'fe',end='');f(0)
f()

DJMcMayhem

1:39 AM

I misunderstood

HyperNeutrino

@MDXF are you going to post the challenge

totallyhuman

wait wat

why is the answer not working on my machine

  File "blah.py", line 3
    for p in permutations(range(n)):z=[*zip((-1,)+p,p+(n,))];c+=all((x<a<y)==(x<b<y)for i,(a,b)in enumerate(z)for(x,y)in map(sorted,z[i%2:i:2]))
                                       ^
SyntaxError: can use starred expression only as assignment target

the heck does that mean

HyperNeutrino

what Python version

totallyhuman

Python 3.4.3

maybe i need 3.5

hmm

HyperNeutrino

It means the * is being evile in your Python version.

replace [*...] with list(...) and it will work

MD XF

1:48 AM

@HyperNeutrino Yeah I just want more support

HyperNeutrino

ok :P

totallyhuman

"you can do this!"

here your support :P

MD XF

2:00 AM

ಠ_ಠ

how 'bout you review it instead of giving me sarcasm :P

ATaco

CMC: Create a program that looks like it shouldn't loop forever, but does. underhanded popularity-contest

totallyhuman

vtc as underhanded is no longer welcome

ATaco

Guys I found a bug in my ability to give a damn

4

RProgN2, 11p{

Phoenix

@ATaco To the one person that knows RProgN2, that may indeed look like it shouldn't loop forever.

Arnold Palmer

I kinda know it at this point

ATaco

2:04 AM

In what situation would that kind of a code loop forever..?

Phoenix

Huh

Arnold Palmer

Confused about what { does by itself and not for a loop or concept

Destructible Lemon

is there an rpg style fighter koth?

ATaco

{} forms a function, AKA concept array, and skips past the matching }, when their isn't a matching }, the default behaviour is to move the IP back to index 0, which then clicks over to 1, and the program loops.

Arnold Palmer

@ATaco You should definitely make a doc for some of this stuff so that people can actually join in on your RProgN2 answers

Phoenix

2:06 AM

a=NaN;while(a!=a);

ATaco

@ArnoldPalmer I plan to.

Magic Octopus Urn

while(""==""){} in java?

lol

HyperNeutrino

lol

ATaco

This allows for a really short quine, {`{.}{

Destructible Lemon

@MagicOctopusUrn that looks like it should loop forever though

Magic Octopus Urn

2:07 AM

Pssh... you didn't say that the person knew the languages caveats.

Phoenix

while(""!="");

Destructible Lemon

@ATaco why doesn't it loop forever

ATaco

} is then on it's own, so it terminates.

Magic Octopus Urn

Ah, you're right.

It is !=.

Jesus, I'm tired ._.

Arnold Palmer

@ATaco Good. It was fun to write the code, but somewhat annoying to learn

HyperNeutrino

2:08 AM

tio.run/##y0osS9TNL0jNy0rJ/v@/…

ATaco

First the program makes the function, {`{.}, then it hits the last {, and moves back to index 1, which is passed the first {, so it starts executing it. ``{` pushes a { literal, and . concatenates the function with the string, } then exits.

That shouldn't loop forever in Java, strings aren't equivalent by content, they're by reference

Destructible Lemon

anyway, how about an rpg fighter koth where you customise abilities but the opponent isn't told what those abilities are

Phoenix

@HyperNeutrino ._.

Magic Octopus Urn

Yeah, exactly, any non-primitive type work work.

HyperNeutrino

lol

Magic Octopus Urn

2:09 AM

Sec... idea.

I forget which numeric types auto unbox and box.

Destructible Lemon

why is everyone ignoring my koth ideas ;_;

ATaco

I'm not a huge fan of KoTH to be honest.

Magic Octopus Urn

I don't know what KoTH is.

I know what it stands for, but not how to play lol

ATaco

You submit a bot, winner is the bot with the highest score.

Your bot is directly challanging other bots, so a winning answer might become absolutely terrible just by the entering of another bot.

Magic Octopus Urn

Ah, so KoTH challenges are almost exclusively in OOP langs?

Destructible Lemon

2:12 AM

@ATaco not necessarily

in some koths only two bots will play each other

ATaco

Generally speaking they are though.

Magic Octopus Urn

I feel like some semblance of inheritance would make that easier.

ATaco

@DestructibleLemon Still directly challanging other bots.

HyperNeutrino

Command Line I/O works too but can be a pain

Destructible Lemon

@MagicOctopusUrn also languages created specifically for the bots

Magic Octopus Urn

2:13 AM

Wow, I need to write a KoTH challenge

Phoenix

@MagicOctopusUrn Destrucitble Lemon keeps trying to write Python koths and no one answers them.

Destructible Lemon

@ATaco yeah, but one bot won't make it terrible

ATaco

There was one KoTH that used a language created for the KoTH.

Magic Octopus Urn

I love OOP bullhonky

Destructible Lemon

@Phoenix I actually only posted one

Phoenix

2:13 AM

Ah

ATaco

It was a very basic language, and the winner was this one bot that turned all the others into slaves.

Destructible Lemon

the other one was too complex for myself to answer

Phoenix

You complained for weeks that no one did your KoTH

Destructible Lemon

;_; yeah

it was sad ;_;

ATaco

I liked the FGD challenge, that was great.

Phoenix

2:14 AM

Was that the one that caused teamspirit.js

ATaco

I wrote a basic genetic algorithm to breed the BEST BOT

Nah, it wasn't.

I never competed in that one.

18

A: The Futuristic Gun Duel

Next, the most feared of all creatures, it's been to hell and back and fought with literally 900000 other bots, its... The BotRobot BotRobot was named, trained and built automatically by a very basic Genetic algorithm. Two teams of 9 were set up against eachother, in each generation, each ...

Step Hen

@MagicOctopusUrn You can do JSON command line stuff

ATaco

Found it, my all time favourite KOTH.

13

Q: Code Bots 3: Parallel Programming Antipatterns

Welcome back! I'm excited to present the 3rd CodeBots challenge. This one has been a long time in the making. This challenge will be split up in 3 sections: the short version, the long version, and additional details. The Short Version Each competitor will write a 24-command program. These b...

king-of-the-hill

The Code Bots series was great.

HyperNeutrino

I'm thinking of making a KoTH that works on a 2D playing field except instead of having a grid, it uses floating point (which is still a grid, but pretty precise)

MD XF

@HyperNeutrino The 'cubify text' challenge title is too short

HyperNeutrino

2:27 AM

rip

Most efficient cubifier

MD XF

Huh that works

TwiNight

@ATaco Agreed

MD XF

Input, anyone....?

1

A: Sandbox for Proposed Challenges

Most efficient cubifier code-challenge ascii Cubically is too tedious to manually write any code in. Your challenge is to translate ASCII text into Cubically source code. Cubically This is just a quick run-down of Cubically; the repository has a more complete guide and details. Cubically is a...

Step Hen

2:48 AM

@MDXF print a Cubically program as output currently we can print any valid Cubically program as output, according to the spec :P

Aka you didn't say it has to output the input, although that's implied from the test cases

Anonymous

@StepHen While it's true that more specificity is better, anyone who tried that would be immediately trout-slapped

Step Hen

@Mego I know, it just took me a click on a link to figure out what was happening

MD XF

3:05 AM

@StepHen ಠ_ಠ

Ok if there are only sarcastic comments to be made, sounds like it's good to post

Phoenix

I think so too

@MDXF Will you be posting today?

MD XF

Probably

As soon as I said I'd post I got two comments in one minute so I think I'll wait a bit longer

Phoenix

Ah

HyperNeutrino

3:24 AM

pls post tomorrow so I don't miss my chance to answer tyvm :) (just kidding post whenever you think it's ready)

well rip now I'm bored cuz i was talking to my friend earlier but she sleeps at more normal times

MD XF

4:04 AM

I'm bored 'cause I got no life

And my ~~Triangular interpreter~~ stupid idiotic brain has an insane bug

I'm gonna buy a rubber duck tomorrow

Downgoat

Idea: the more times a post is reopened/reclosed the higher the rep requirement is to reopen/reclose again

Zizouz212

@Downgoat Meh, you're better off to flag mods to just lock it

MD XF

(ノ°Д°）ノ︵ ┻━┻ @HyperNeutrino if no further comments prevent it, I'll post tomorrow

Downgoat

Yeah Dennis ended up locking it

MD XF

@Downgoat Which post are you talking about?

Downgoat

4:18 AM

Fibonacci with subtraction

Zizouz212

@Downgoat The stepped increases on reclosure/opening will kind of just provoke debate. Not healthy for a site

MD XF

@Downgoat pls link, can't find it

Downgoat

But low rep users w/ reopen powers generally want what gives them most rep to be open not what's best for site

28

Q: Fibtraction - Fibonacci but with subtraction

This question's "duplicality" is being questioned here. The Fibtraction sequence (as I call it) is similar to the Fibonacci sequence except, instead of adding numbers, you subtract them. The first few numbers of this challenge are: 1, 2, -1, 3, -4, 7, -11, 18, -29, 47, -76, 123, -199, 322, -52...

code-golf number sequence fibonacci

MD XF

thanks

Downgoat

A script correlating voting behavior with rep/challenge behavior would be interesting

Wheat Wizard

5:05 AM

@Downgoat I very much agree with the comment you left

New Main Posts

0

Q: Find out the three digits A,B and C that satisfies AB * C = AAA

Create a program that finds out the three digits A, B and C that satisfies the following formula. AB * C = AAA No input value required. The shortest code that outputs the digits A, B and C wins. For example, if A is 1, B is 2 and C is 3, The output result can be 1 2 3 You should not just pr...

code-golf number

Fatalize

6:06 AM

Is it me or is Github ultra slow?

ATaco

Github thinks I'm a time traveler.

(It knows too much)

Destructible Lemon

6:55 AM

what if a koth that involves a bunch of timetravelling somehow

Leaky Nun

7:09 AM

"""
integer factorization
using quadratic sieve
implemented by Kenny Lau (aka Leaky Nun)
"""

from math import *
import time

def modpow(a,b,c):
	a %= c
	res = 1
	while b:
		if(b%2==1): res = res*a%c
		a = a**2%c
		b //= 2
	return res

def ressol(p,n):
	"Tonelli–Shanks algorithm"

	if p==2: return n%2
	Q = p-1
	S = 0
	while Q%2==0:
		S += 1
		Q //= 2
	z = 2
	while modpow(z,(p-1)//2,p)==1: z += 1
	M = S
	c = modpow(z,Q,p)
	t = modpow(n,Q,p)
	R = modpow(n,(Q+1)//2,p)
	while t != 1:
		i = 0
		tt = t

Note that this is for demonstration only and will not work for almost any number :P

It will work for 2202298669

trichoplax

8:55 AM

@DestructibleLemon Possibly relevant

Destructible Lemon

what if there was a koth where one player tried to create a paradox and one bot tried to prevent it

the only issue then is possibly the halting problem

Mayube

@DestructibleLemon that would be a C&R challenge not a koth, also define paradox

Destructible Lemon

grandfather paradox style

Mayube

define paradox

Destructible Lemon

well, see

if you were to go back in time and prevent your grandfather from having children, you wouldn't exist

trichoplax

8:59 AM

I guess you'd need to define your rules of time travel too. Does changing the past just overwrite the timeline, split off a new one, create several new ones but exclude the original?

Destructible Lemon

then, you wouldn't be able to go back in time and prevent your grandfather from having children

Mayube

you can't just put "create a paradox" in your challenge, it needs a clear, unambiguous definition

Destructible Lemon

also, as mentioned, this koth is undecidable

trichoplax

Writing Sci Fi about time travel is easy, as loopholes don't make it crash. A KotH would be much more challenging. Might be worth it though...

Destructible Lemon

yeah... I just realised that this actually makes it really difficult...

which resolves first... your changes to the past, or the other bots reaction to your time travelling

so, here is an example of a paradox you could do

(actually paradoxes are incredibly easy to create...)

so, you go into an area, and you check if there is a red rock there.

if there is no red rock, go back in time and place on there

otherwise, do nothing

again, this has issues with the halting problem unless I reduce a fair amount of possibilities

hmmm

I think there might have to be threading even

well, more dovetailing than threading

maybe the watcher can have semiomniscience or something

@Mayube actually, there have been two sided koths before

SIGSEGV

9:54 AM

Wow

New Main Posts

0

Q: Make a Word Art

No, not that thing in powerpoint You will be given a string, and a 2D array of boolean values. The 2D array will represent a picture. You will be creating art out of it. Let me show you how. The steps to art First, you create a square which fits the 2d array, with the string. Like if th...

code-golf ascii-art

SIGSEGV

I don't know why a single challenge about P(n,k)wasn't made

Cows quack

Please don't post a challenge to main without testcases

3

SIGSEGV

@Cowsquack Oh right, but I was on my tablet so it's quite hard to add testcases.

I'm gonna add some when I have some time

btw there's one very little example there. you can try that for now.

Mr. Xcoder

@Cowsquack Did you solve the gnu sed problem?

Cows quack

10:05 AM

no

Mr. Xcoder

I am available to help you if it's still needed

I have time now

Cows quack

Thanks. First get GNU-sed on macOS using brew. Then once you get it, try running cat file.txt | gsed "$!N;s/\n//g" where file.txt is a file containing text over newlines

this works on TIO's sed, but not on my device for some reason

I want to know if it is just because brew messed something up, or if it was me who messed something up

Mr. Xcoder

Ok, wait bit until Homebrew updates

Cows quack

result on TIO: Try it online!

but I get a -bash: !N: event not found

gtg

programmer5000

\e\s\c\a\p\e\ \s\o\m\e\t\h\i\n\g

Mr. Xcoder

10:10 AM

@Cowsquack I'll ping you when I'm done

@Cowsquack I get -bash: !N: event not found

programmer5000

Is it OK to ban hashing / one-way functions in a CnR contest

Cows quack

@Mr.Xcoder gah

Mr. Xcoder

@Cowsquack So...

I've put this exact text into file.txt:

asdas|
dasdasdad|
asdasda|
asdas|
dad|
ad|
asdad|
asd|

Result above ^

Cows quack

@programmer5000 escape what exactly?

@Mr.Xcoder thanks anyways

Mr. Xcoder

@Cowsquack The good part is that I have gnu-sed now :p

Cows quack

10:16 AM

hmmm... when I save the sed program as a file it works as intended

@Mr.Xcoder sed is a nice language for golfing

Mr. Xcoder

@Cowsquack I guess I'll have to learn it. I'll stick to Python, Swift and Pyth for now

Mayube

sed is pretty much just /// in unix command format

Cows quack

@Mr.Xcoder It works when you use '' instead of ""!

Mayube

it's more a regex find-replace tool than a language

Mr. Xcoder

@Cowsquack That was... it?!

Mayube

10:21 AM

although I believe it has more power than regular old regex

Leaky Nun

in Mathematics, 3 mins ago, by Leaky Nun

$$\begin{cases}
x_0=&\min(b_0,x_1+c_1) \\
x_1=&\min(b_1,x_0+c_0,x_2+c_2) \\
x_2=&\min(b_2,x_1+c_1,x_3+c_3) \\
\cdots\\
x_7=&\min(b_7,x_6+c_6,x_8+c_8) \\
x_8=&\min(b_8,x_7+c_7,x_9+c_9) \\
x_9=&\min(b_9,x_8+c_8) \\
\end{cases}$$

in Mathematics, 3 mins ago, by Leaky Nun

I need to solve for $x_0$ to $x_9$

How do I solve such equations?

The $b$ constants and the $c$ constants are all positive integers.

And the $x$ variables are also positive integers.

in Mathematics, 2 mins ago, by Leaky Nun

It's actually an MCFP, but I haven't read through the algorithms yet...

TheLethalCoder

Does anyone know what challenge it was when taking the input string AB you outputted AB\nBA? Like in this challenge: codegolf.stackexchange.com/questions/133709/make-a-word-art/…

Leaky Nun

@TheLethalCoder the square challenge?

Mr. Xcoder

@TheLethalCoder There were a couple of similar CMCs

In C#, if you have for(i=0;...) isn't it the same as for(i;...)? I don't really know C#, so it's just a question

TheLethalCoder

10:37 AM

@LeakyNun I think it was something like that. I can't find it at the moment.

Leaky Nun

22

Q: Making Squared Words

The Challenge Your task is to create a program that takes any given string input, and outputs the input in a squared format. Empty strings should return an empty string. Examples Given the input: golf Your program should output: golf o l l o flog Input: 123 Output: 123 2 2 321 In...

code-golf string

Mr. Xcoder

@TheLethalCoder Can you add a tio link to your answer?

TheLethalCoder

@Mr.Xcoder Yes but depends on the context, sometimes it will complain because you will have to initialise the variable.

Mr. Xcoder

CMC: Given a String, make a complex Stairway (test cases to come)

TheLethalCoder

@LeakyNun No didn't mean that one... more like ABC becomes ABC\nBCA\nCAB or something along those lines.

Mr. Xcoder

10:39 AM

abcd ->

abcd
 bcda
  cdab
   dabc

Arrays of Strings are not valid.

totallyhuman

Aw c'mon

TheLethalCoder

@Mr.Xcoder Added, didn't want to add too much until the OP clarifies on some of our questions.

Leaky Nun

59

Q: Print a Tabula Recta!

Print a Tabula Recta! The Tabula Recta (sometimes called a 'Vigenere Table'), was created by Johannes Trithemius, and has been used in several ciphers, including all variants of Bellaso's Vigenere cipher and the Trithemius cipher. It looks like this: ABCDEFGHIJKLMNOPQRSTUVWXYZ BCDEFGHIJKLMNOPQR...

code-golf string kolmogorov-complexity cryptography alphabet

@TheLethalCoder

TheLethalCoder

@LeakyNun Yeah it was that but I'm sure there was one that was the same but took input. Maybe I'm making it up.

Leaky Nun

CMC: use a language that hasn't been used in the following challenge to solve the following challenge

59

Q: Print a Tabula Recta!

Print a Tabula Recta! The Tabula Recta (sometimes called a 'Vigenere Table'), was created by Johannes Trithemius, and has been used in several ciphers, including all variants of Bellaso's Vigenere cipher and the Trithemius cipher. It looks like this: ABCDEFGHIJKLMNOPQRSTUVWXYZ BCDEFGHIJKLMNOPQR...

code-golf string kolmogorov-complexity cryptography alphabet

TheLethalCoder

10:46 AM

@Mr.Xcoder C#, 114 bytes: s=>{var r="";for(int i=0;i<s.Length;)r+="".PadLeft(i)+s.Substring(i,s.Length-i)+s.Substring(0,i++)+"\‌n";return r;}

What's the usually CMC answer format? I haven't done one before...

@Mr.Xcoder Should make this into an actual challenge it's quite fun to solve. Though I'd already done most of it for the previous challenge I answered.

Leaky Nun

@Mr.Xcoder 11 bytes in Pyth

TheLethalCoder

@Mr.Xcoder C# with Linq, 128 bytes:

using System.Linq;s=>string.Join("\n",new int[s.Length].Select((_,i)=>"".PadLeft(i)+s.Substring(i,s.Length-i)+s.Substring(‌0,i)))

Leaky Nun

@Mr.Xcoder Jelly, 9 bytes: LḶð⁶ẋżṙ@Y

@Mr.Xcoder Python, 61 bytes: s=input();S="";exec("print(S+s);S+=' ';s=s[1:]+s[0];"*len(s))

60 bytes: s=input();t=S="";while s:print(S+s+t);S+=" ";t+=s[0];s=s[1:]

I changed a newline to a semicolon here for formatting

55 bytes: s=input();i=0;while s[i:]:print(i*" "+s[i:]+s[:i]);i+=1

Mr. Xcoder

@LeakyNun Hmm, I'll try to tie you

@LeakyNun I have to golf 1 more byte: j.e+*kd.<QbU

Leaky Nun

11:01 AM

If you .e on U, then k and b are always the same...

Mr. Xcoder

> If you .e on U

Hmmm

Duh, I'm so dumb

Rewriting now

@LeakyNun Bingo, 11 bytes: j.e+*kd.<Qk

Leaky Nun

right.

I used m instead though. Figure out a 11-byte solution using m.

(Hint: ; would be helpful)

Mr. Xcoder

@LeakyNun I should try to solve it with m too, working on it now

Do you have nested lambdas?

Leaky Nun

I don't

New Main Posts

-4

Q: Unable to open a webpage in safari

When I try to an open web page, I'm getting below error. Safari can’t open the page “https://abc.pqrs.com” because Safari can’t establish a secure connection to the server “abc.pqrs.com”. But the same web page can be accessed in Chrome and Firefox. The only safari on Mac has this issue. Safari...

browser

Mr. Xcoder

11:11 AM

@LeakyNun Do you use " " instead of d?

Leaky Nun

@Mr.Xcoder of course, but it would not be golfy

Mr. Xcoder

Because m uses <l:d>

Cows quack

@LeakyNun sed, 71 bytes: Try it online!

Leaky Nun

@Mr.Xcoder did you read my hint?

Mr. Xcoder

@LeakyNun How would you use d in a m

@LeakyNun I did

Leaky Nun

11:12 AM

@Cowsquack output does not match

Mr. Xcoder

But it seems like I didn't understand the meaning of if not inside a lambda function

Leaky Nun

;                         End all containing functions, statements, etc., if not inside a lambda function.
;                         Global value of innermost lambda's first variable.

Cows quack

@LeakyNun 73 bytes: Try it online!

Leaky Nun

The second one @Mr.Xcoder

@Cowsquack and then submit it :D

Cows quack

are trailing newlines allowed?

Leaky Nun

11:17 AM

@Cowsquack read the challenge :D

I don't own the challenge

Cows quack