The Nineteenth Byte

Cᴏɴᴏʀ O'Bʀɪᴇɴ

20:01

@El'endiaStarman Uhhh the bots aren't loading in the spacewar simulation

El'endia Starman

Just tried a random pair. Looks like they do.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

o_O it's working now

blame caching

El'endia Starman

:P

flawr

Hello=)

El'endia Starman

hi

flawr

20:07

I think Starman isn't your real name, is it?=)

El'endia Starman

Oh no, it's not. :P

Cᴏɴᴏʀ O'Bʀɪᴇɴ

hi @flawr

El'endia Starman

Though, on the Internet, it basically is.

Dennis

3

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

Parse a tree for pruning code-golf ascii-art Windows supplies users with tree: a neat little tool that converts a directory tree to ASCII-CP437 art. It's a very human-readable format. However, it's a bit useless if you want the directory tree of an entire drive, or even just the Windows folder,...

Dennis

20:08

Does anyone else have the same font problem?

flawr

Why not Galaxyman??

=P

El'endia Starman

With what? The strikethrough? The badge positioning? The random space in "Do ng"'s name?

Dennis

@El'endiaStarman I think he prefers Downgoat, so that.

wizzwizz4

@NewSandboxedPosts What do you think of Parse a tree for pruning?

No, I wasn't talking to a bot...

Cᴏɴᴏʀ O'Bʀɪᴇɴ

Yes, you are ;)

El'endia Starman

20:11

@Dennis Oh, I didn't make the connection. You're not the only one with that problem.

58 mins ago, by Sherlock9

Interestingly, when I type your name on mobile, it drops some characters. So I get CNRO'BRIN

Cᴏɴᴏʀ O'Bʀɪᴇɴ

sᴏ ʏᴏᴜ ᴍᴏʙɪʟᴇ ʜɪᴘsᴛᴇʀs ᴄᴀɴɴᴏᴛ sᴇᴇ ᴛʜɪs ᴀᴡᴇsᴏᴍᴇ ᴛᴇxᴛ?

Adnan

@CᴏɴᴏʀO'Bʀɪᴇɴ How do you output something in Jolf?

I got the code vH*99H

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@Adnan It's implicit, at the end, but a also does that.

@Adnan repeating H 99 times? what are you doing? XD

Adnan

Wat hahaha

Cᴏɴᴏʀ O'Bʀɪᴇɴ

a(value)

wizzwizz4

20:14

0

A: Sandbox for Proposed Challenges

Parse a tree for pruning code-golf ascii-art Windows supplies users with tree: a neat little tool that converts a directory tree to ASCII-CP437 art. It's a very human-readable format. However, it's a bit useless if you want the directory tree of an entire drive, or even just the Windows folder,...

Adnan

Huh

How do you assign 9 * 9 to H?

Cᴏɴᴏʀ O'Bʀɪᴇɴ

oh yeah that's it :P

I forgot I changed that

wizzwizz4

@wizzwizz4 If nobody has any comments about my challenge, I'll just post it as a question.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

oH*99 or vH*99

@wizzwizz4 ಠ_ಠ

how long have you waited?

Alex A.

@wizzwizz4 Best to leave it in the sandbox for a while

wizzwizz4

20:16

I know. Feigning impatience seems to get people's attention though! ;-p

Alex A.

ಠ_ಠ

3

Adnan

@CᴏɴᴏʀO'Bʀɪᴇɴ How about this

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@Adnan Ah, I forgot. v can only be used after defined. Use o.

this should work

Adnan

Ahhh, it works :)

Thanks!

Cᴏɴᴏʀ O'Bʀɪᴇɴ

No problem!

ಠ_ಠ

20:30

@wizzwizz4 You better appreciate my new profile description.

Alex A.

@ಠ_ಠ Illuminati confirmed??

ಠ_ಠ

status-confirmed

Alex A.

hahaha

half-life-3 status-confirmed

ಠ_ಠ

half-life-3 = 1.5-life

do-the-math

Alex A.

math status-completed

I did the math

ಠ_ಠ

20:34

he-did-the-monster-math

Alex A.

$user image$

ಠ_ಠ

I was referring to this.

Monster Mash

►

Alex A.

I know :P

ಠ_ಠ

reddit.com/r/itwasagraveyardgraph

Nathan Merrill

hmm...

ಠ_ಠ

20:48

reddit.com/r/itwasagraveyardgraph/comments/3s3gfx/…

Nathan Merrill

code bowling measured by bytes after some compression method

does that remove the majority of problems code bowling has?

ಠ_ಠ

Good idea.

flawr

@NathanMerrill I think we should test it in a simple challenge=)

I really like this idea too.

Nathan Merrill

what's a good task that hasn't been overused?

I'll post a sandbox

oooh, a bowling simulator

is .7z accessible to linux users?

by accessible I mean typical/ease of use

Doᴡɴɢᴏᴀᴛ

@Dennis I'm a dong :O

3

Doorknob 冰

20:59

@NathanMerrill yes

On Debian it's just apt-get install p7zip

Alex A.

7-zip.org/download.html

Binaries for everyone!

quintopia

21:12

I see no reason compressed code bowling would be an improvement. "HAY I NEED THE VALUE OF PI HERE SO LET ME JUST WRITE IT TO 10000 DECIMAL PLACES BTW PI IS INCOMPRESSIBLE"

Nathan Merrill

@quintopia fair point

if there was a language restriction, then limiting the number of statements might work

except not

hmmm

Alex A.

booo language restrictions

Nathan Merrill

not planning on doing the challenge any more

quintopia made a good point

Alex A.

Using the letter O in place of a 0 was extremely convincing.

Nathan Merrill

still doing a bowling themed challenge though :P

quintopia

21:22

qr.ae/RgRZHu

This is an interesting algorithm

Not superfast, but definitely easy to implement in heavily recursive languages

mınxomaτ

On the topic of compression, this is probably going live soon, unless any major complaints arise in the next two days or so.

Alex A.

Related algorithm: bit.ly/1e1EYJv

El'endia Starman

ಠ_ಠ

flawr

Why should pi be incompressible?

Alex A.

@flawr There's no known repetition? Idk

mınxomaτ

21:28

^

Nathan Merrill

oooh, what if a cops and robbers style challenge where the cops write a program, and robbers write another program to print the cops' program

mınxomaτ

@AlexA. So? Still doesn't make it incompressible. Or more random.

Alex A.

Hence "idk"

Nathan Merrill

the cops try to maximize the minimal generating program

Alex A.

Because idk

Nathan Merrill

21:29

and the robbers try to minimize it

Doorknob 冰

Of course pi is compressible

see: pi-calculation algorithms

flawr

pi = 22/7

quintopia

@Doorknob冰 its not compressible by generic compression algorithms currently available. One has to know one is trying to output pi in order to compress it.

flawr

pi = 1 in base pi?=)

mınxomaτ

@quintopia [citation-needed]

Doorknob 冰

21:38

@mınxomaτ Well, my intuition tells me "you can't take a number and unambiguously turn it into a smaller number reversibly"

quintopia

@mınxomaτ blahblah assuming pi is normal which everyone believes but no one can prove blahblah

mınxomaτ

@Doorknob冰 Yeah, no compression in unambiguous. But that doesn't make things incompressible.

Doorknob 冰

@mınxomaτ By "unambiguous" I mean "only one possible output per input"

mınxomaτ

@Doorknob冰 I know.

Doorknob 冰

and only one possible input per output

flawr

21:40

How about lossy-text compression?

Lossy pi-compression?=P

quintopia

Well, for instance, the real number given in binary as 0.1101001000100001000001000000100000001000000001... never repeats but is definitely compressible. No one believes pi is like this....

mınxomaτ

> No one believes pi is like this

Yeah, of course it is. If it is infinite, it can be represented by an infinite number of bytes (i.e.) bits. There's no indication in the (few) first digits that pi has a serial correlation coefficient of 0, actually it's the opposite. Truly incompressible files have a SCC of 0. It's fairly easy to create them, one is included as a sanity check in my compression challenge (link above).

The only reference to your statement is your own discussion at xkcd forums and your friend.

flawr

Pi =

11.00100100001111110110101010001000100001011010001100001000110100110001001100011‌001100010100010111000000011011100000111001101000100101001000000100100111000001000‌100010100110011111001100011101000000001000001011101111101010011000111011000100111‌00110110010001001010001010010100...

quartata

21:56

Hello

Alex A.

@quartata hi

quartata

@NathanMerrill Could do something like atomic-code-golf

I actually think measuring tokens might be a good fit for code bowling

That way having 10,000 digits of pi doesn't matter because it is still one token

Nathan Merrill

I'm thinking of doing something similar

quartata

Part of the problem is that we haven't actually ever had a good atomic-code-golf either...

Nathan Merrill

er, not really

I"m almost done with my sandbox post

then you guys can vote it down

flawr

22:02

You know, the votes wrap around at -2^31

quartata

hehe

Nathan Merrill

lol

0

A: Sandbox for Proposed Challenges

Compressed Code Bowling Cops You need to write some code that takes an array of integers and prints out the sum of the integers. Robbers are going to produce a program that generates your code. You win by making the robber's code as big as possible. Robbers Your program needs to output the ...

posted

quartata

Mkay.

I might try a hand at an atomic-code-bowling here.

It seems like a decent idea.

El'endia Starman

That sounds....destructive.

Nathan Merrill

lol

quartata

22:05

The only other way I can think of making code bowling work is a popularity-bowling :/

trichoplax

Bowling is not challenging without some sort of restriction. There might still be some kind of hybrid bowling that could work.

@NathanMerrill This does seem like a good way to counter the tendency to introduce useless code. I'm interested to see how it turns out (+1)

flawr

overhanded-bowling

Nathan Merrill

@trichoplax thanks :P

I'm looking through past code bowling efforts, and most of them won't work on my sandboxed post

bah @MartinBüttner

Martin Büttner

@trichoplax I don't see how it avoids the problems of the last code-bowling cops-and-robbers.

trichoplax

@NathanMerrill I like the idea of being able to reduce whitespace and variables, but it might still be hard to define what changes are acceptable. At the extreme, I know you don't want robbers that just write code that outputs valid but unrelated source code, but I don't know how a line could be drawn clearly.

New Sandboxed Posts

22:12

1

A: Sandbox for Proposed Challenges

Compressed Code Bowling Cops You need to write some code that takes an array of integers and prints out the sum of the integers. Robbers are going to produce a program that generates your code. You win if the smallest generating code is bigger than any other cops' submission. Robbers Your p...

Nathan Merrill

@NewSandboxedPosts is the weather nice?

trichoplax

@MartinBüttner I'm really not up to date - I'll go and have a look...

Nathan Merrill

@trichoplax yeah, that's definitely the hardest part of writing this challenge

Martin Büttner

@trichoplax it's been a while. essentially you encode your code in a unary number and get that number from a string's length.

Nathan Merrill

@MartinBüttner would disallowing "eval" be reasonable?

it seems that much of the problems of code bowling has to do with the eval statement

Martin Büttner

22:15

@NathanMerrill that's cool, I'll just write a Unary interpreter.

(and write a list-summing program in Brainfuck/Unary to embed in my code)

quartata

Hmm... how should I define a token exactly

Language dependent :/

trichoplax

@MartinBüttner Under the sandbox post's rules, it seems you could output another string of the same length, and it would count as a valid robber. Which means complicating the string won't help the cop. Does that improve anything?

Martin Büttner

@quartata the problem of every atomic code golf ever.

flawr

@NathanMerrill Then again, what exactly defines "eval"?

Martin Büttner

@trichoplax I can probably include some checksum which breaks the program if the actual characters change.

Nathan Merrill

22:19

@flawr take this string and execute it

trichoplax

@MartinBüttner Oh yeah...

Nathan Merrill

@MartinBüttner but unary is easy for a program to produce

and short

wait, can unary be any character?

Martin Büttner

@NathanMerrill well, I meant Lenguage, not Unary. the point was not the specific language, but that instead of using eval I can just interpret the code myself, by interpreting a different language.

quartata

@NathanMerrill Sure, you can use any symbol you like to represent a digit

Nathan Merrill

I'm defining "eval" as taking a string and executing it (don't care about the language the string is in)

Martin Büttner

22:21

ummm

if I write that executing code myself, I really don't see how you're going to find an objective definition for what qualifies as "eval"

trichoplax

As an alternative to code golf, there are challenges with an upper limit on code length, and you have to perform as much as possible without going over that limit. So an alternative to code bowling would be a challenge with a lower limit on code length, and you have to perform as little as possible without going under that limit. This seems to confirm that code bowling is almost impossible to make an interesting question for...

Martin Büttner

@quartata not in the language Unary

quartata

@MartinBüttner Oh, I didn't know he meant uppercase Unary :P

@NathanMerrill Technically blocks are strings in GolfScript, meaning that evaluating a block (say for a loop) falls under your category for eval

It's not quite a bullet-proof definition sadly

Nathan Merrill

I'm ok with a broad definition of "eval" that would of-necessity exclude languages (such as Golfscript)

flawr

@trichoplax I like that idea too.

Nathan Merrill

22:26

@trichoplax define "as little as possible"

Martin Büttner

@NathanMerrill I'm not sure I understand your definition of eval, but it seems to contradict Rice's theorem.

trichoplax

Maybe there could be a challenge to produce code of a fixed (question-defined) length, and your score is the minimum number of character edits required to make it run without error.

Has that been done?

Nathan Merrill

@trichoplax are you trying to maximize the minimum?

Martin Büttner

@trichoplax seems like I can choose Unary (the language), and just use N non-0 characters

trichoplax

@NathanMerrill Yes - make the code as difficult to fix as possible

Martin Büttner

22:28

(or any other language, which errors on unknown characters and use N of those unknown characters)

trichoplax

@MartinBüttner Hmmm. Yes.

Nathan Merrill

@trichoplax I'd just post a series of random characters and say the language is Java

Martin Büttner

@NathanMerrill that is not guaranteed to get a score of N ;)

trichoplax

@NathanMerrill Requires changing each character at least N times before errors cease. Score: N^2

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

Identifying spies in "Resistance" This is still very rough, but I think it has the makings of an interesting challenge. Please help me improve it. What do I need to add? What do I need clarify? Resistance is a party game that pits "resistance members" against "imperial spies" on a series of mis...

trichoplax

22:33

@MartinBüttner What if the original code has to give no compile time errors, only run time errors?

quartata

I think that the only way I could get atomic-code-bowling to work is if the answers had to be in a certain language

trichoplax

(or rough equivalent for interpreted languages)

Martin Büttner

@trichoplax I'm not sure that's a well-defined distinction for interpreted languages

quartata

I just can't think of a good general definition of token here.

Martin Büttner

ah yes, "rough equivalent" :P

trichoplax

22:34

@MartinBüttner Yes that would be the difficulty :)

But would it even work for compiled languages?

Martin Büttner

@quartata the only way atomic-code-golf ever works is by defining simple toy-languages for the challenge.

trichoplax

I don't mind excluding a subset of languages

Martin Büttner

@quartata like this: codegolf.stackexchange.com/q/37188/8478

El'endia Starman

What are tokens in, say, Befunge?

quartata

@El'endiaStarman Individual non-whitespace chars.

Martin Büttner

22:36

why non-whitespace? clearly, the whitespace is vital for the program to work?

quartata

They are just empty spaces on the grid.

Martin Büttner

I can't remove them without breaking the program though

El'endia Starman

Some of it is necessary, though.

Martin Büttner

especially the linefeeds

but neither the spaces

El'endia Starman

Trailing spaces can usually be removed.

quartata

22:37

Right, but removing the whitespace results in the non-whitespace chars being in a different location on the grid which is why it breaks

Martin Büttner

yeah, so the whitespace is definitely significant for the program to work

quartata

I don't consider the whitespace to be tokens, they just make up more the shape of the grid

Martin Büttner

so I don't see why it shouldn't be counted

quartata

The interpreter itself doesn't do anything with the whitespace specifically

Martin Büttner

anyway, atomic code golf is also susceptible to encoding the actual code in a single string and eval-ing it

quartata

22:38

This is code bowling in this case.

So that would be somewhat detrimental

Martin Büttner

ah right, what's stopping me from blowing up the code here?

quartata

With a good definition of tokens, I don't see a way to arbitrarily pad code. Whitespace doesn't count, comments don't count...

Martin Büttner

there is an infinite number of programs (ignoring whitespace and comments) which solve any given problem. clearly, these must be arbitrarily large.

quartata

Right, but it actually takes effort to make them.

The issue with code bowling was that usually it was too easy to pad programs

mınxomaτ

@quartata There are obfuscators. They blow up the code massively while having no dead code.

Martin Büttner

22:40

but then it's just an exercise in patience of adding another pointless indirection to the algorithm

it is still way too easy to pad programs

if I need a numeric literal I'll just replace it with an arithmetic expression with 5000 operands.

quartata

Hm

I suppose that depends on the task.

I was planning on making the task a primality test

trichoplax

Maybe someone needs to design a bowling language that doesn't have these problems.

Martin Büttner

I'm not sure what the task has to do with it.

quartata

No literals are involved, so that eliminates a place for padding

Martin Büttner

@trichoplax by not being Turing-complete? ;)

quartata

22:43

But I guess you could just calculate a literal and not use it or something

trichoplax

@MartinBüttner At least :)

Martin Büttner

@quartata how are there no literals involved? I'm sure I'll need a for-loop somewhere...

New Main Posts

0

Q: Not Truely False

The goal of the program is to break your language so that the check if false: passes. You may not fake us out by setting something that looks like the variable false then checking that. You must actually override a False check. Bonus points: Make if false and not true pass. Bonus bonus points: M...

quartata

@MartinBüttner Oh, you mean something like for(int i = (2-2)+(2-2)+(2-2)+...

El'endia Starman

Tricksy chess puzzle.

trichoplax

22:45

Is underhanded not banned?

El'endia Starman

(I haven't solved it yet, so no spoilers!)

Martin Büttner

@trichoplax unfortunately not

@quartata for instance...

quartata

@trichoplax I know, I still think it is too much like code-trolling

luckily we don't see too much of it

El'endia Starman

@Doorknob冰: Look a few messages up for a chess puzzle.

trichoplax

@quartata Can we just make it a synonym and skip the meta discussion?

Doorknob 冰

22:46

@El'endiaStarman I think I've seen that exact one before, heh

quartata

@trichoplax pffft

El'endia Starman

@Doorknob冰 ah, lol

quartata

Sadly I don't think we can since the tag was already made

@MartinBüttner All right, forget it. Too much effort for something that won't even be that fun in the end...

Martin Büttner

@quartata we could.

quartata

Really?

Martin Büttner

22:47

there's a distinction between the two though

code trolling was "make something that doesn't do what the question asks"

underhanded is usually "make something that appears to be doing x, but does y instead"

it's a lot more specific, but usually not much better, with very few exceptions

quintopia

I think we need more reeeeeeeally hard fgitw challenges

El'endia Starman

What's a fastest-gun-in-the-west challenge?

Maltysen

a really easy one?

trichoplax

a popularity contest?

Adnan

I'm not sure, but I think it's like this one

Martin Büttner

22:59

@quintopia is it code-golf-is-boring-let's-resurrect-a-challenge-type-that-was-never-a-good-idea day? :)

5

Adnan

29

Q: Catalan Numbers

The Catalan numbers (OEIS) are a sequence of natural numbers often appearing in combinatorics. The nth Catalan number is the number of Dyck words (balanced strings of parenthesis or brackets such as [[][]]; formally defined as a string using two characters a and b such that any substring starti...

code-golf number sequence combinatorics number-theory

Since you need to be quick

El'endia Starman

That's totally oxymoronic combined with "reeeeeeeally hard" though.

Martin Büttner

we used to have a meta post that asked for ideas for new challenge types (instead of a meta post proposing a single new challenge type)... where did that go...

Nathan Merrill

challenge idea: Take my random string of characters, insert characters into it (any location/order you like) to make a program that does X

code-golf

Martin Büttner

that doesn't sound too bad

although it will be hard to strike the balance between string length and task difficulty

mınxomaτ

23:07

I honestly didn't think you could even USE emoji in variable names. Or that there were so many different crying ones.

last panel.

quartata

lol

mınxomaτ

challenge-idea: Make a program that pokes Randall with a stick if he's procrastinating a(nother) What-If? release.

trichoplax

19

Q: Let's create some new types of challenges!

Our site needs unique content. The more different and new a question is, the more interesting it will probably be. Therefore, let's propose new genres of challenges! What exactly is a challenge genre? It's one of these. The most commonly used ones are code-golf, code-challenge, and popularity-co...

discussion

@MartinBüttner This one?

Martin Büttner

how did I not find this when searching for "new challenge types"

anyway, this is the answer I was looking for and what I thought quintopia was talking about:

-7

A: Let's create some new types of challenges!

First Past The Post To be used for challenges that are genuinely difficult, and/or require solving some kind of puzzle that only has one answer. The winner is simply the first person to post a correct solution.

trichoplax

@MartinBüttner My round about search method was: search for "challenge is:question" and then sort by votes and read through until I find it...

(because I vaguely remembered it being highly voted...)

quintopia

23:20

@MartinBüttner exactly. What's so bad about a problem solving challenge so difficult that being able to solve it at all is an accomplishment, but once someone has shown how to do it, golfing it is trivial?

Martin Büttner

@quintopia see my comments on the answer I just linked

trichoplax

I like seeing code challenges that are difficult, but I don't see that this should make subsequent answers redundant. Even if the question is a deliberate puzzle with an approach in mind, someone may still find something better (unless like me, you post a question which someone proves an optimal solution to).

quintopia

@MartinBüttner how about multihole challenges with hidden solutions

Martin Büttner

I'm not sure what you mean, but it reminds me that I wanted to write up a meta post about multihole challenges...

New Main Posts

1

Q: The Abelian Orders

Some background In math, a group is a tuple (G, •) where G is a set and • is an operation on G such that for any two elements x and y in G, x • y is also in G. For some x, y, z in G, basic group axioms are as follows: G is closed under •, i.e. x • y in G The operation • is associative, i.e. x...

code-golf math sequence abstract-algebra

Alex A.

23:38

Oh it worked

If you edit the feeds post it updates

El'endia Starman

Yes...but I don't see an edit icon?

flawr

good night guys

El'endia Starman

G'night!

Alex A.

Good night!

@El'endiaStarman Downward arrow on the left side of the post when you hover over it, click, "edit" in the bottom left. It's not there for you?

El'endia Starman

@AlexA. I mean, I know that if you edit a feed post, it re-oneboxes. But I don't see the pencil edit icon on the most recent one.

Alex A.

23:42

Oh really?

It shows up for me

El'endia Starman

I also don't see a history link.

[refreshes] There it is.

Strange. That's not usually a problem.

mınxomaτ

Interesting talk: YouTube - "Evidence-Oriented Programming" by Andreas Stefik

Transcript for