The Nineteenth Byte

Anonymous

3:00 PM

Conjecture: the only way to have 4/9 in a 3x3 is with a rotation of Martin's 4/9 solution

quintopia

I've got a python solution for it if it ever gets unholded:

On the spot! Will you try for the other bonus? — jose_castro_arnaud 17 hours ago

Nathan Merrill

110
011
000

quintopia

Oops

1

A: Quine Pride Parade!

Aubergine, 7*24+1-9=160-140=20-30%=14 bytes -a1+a1=oA=Bi-BA:bB=iaooo o o o I am a quine written o o in Aubergine, and o o very proud of it! o o o oooooooooooooooooooooooo (removethis) The (removethis) is not code, but is just there to protect ...

Anonymous

@NathanMerrill Good catch. I modify my conjecture to be a rotation/reflection of yours or Martin's solutions

Nathan Merrill

conjecture:

any 3x3 square with 4 squares filled in and no 3-in-a-row can be tiled without any 3-in-a-row

Anonymous

3:04 PM

100
001
110

3

Nathan Merrill

fair

randomra

@Dennis nice J solution, I completely forgot about _&q: and used __{:@q:]

also, what is the "sock avatar" next to Dennis's regular avatar in the chat?

Anonymous

Another user with the same username

Anonymous

Presumably another of Alex's socks

Martin Büttner

...

Anonymous

3:07 PM

:P

Anonymous

The greatest mystery of PPCG is who @ಠ_ಠ belongs to

anOKsquirrel

isn't ಠ_ಠ a normal user? if not I place my bets on Alex

Martin Büttner

@Mego it's not a mystery to everyone ;)

Anonymous

We're 90% certain @ಠ_ಠ is a sock of somebody's, because it has only made one post, for the sole purpose of getting chat privileges

Anonymous

@MartinBüttner Yeah well the mods aren't gonna spill the beans, so us ~~peasants~~ normal users have to figure it out for ourselves

anOKsquirrel

3:10 PM

ah

Anonymous

It's a common belief/joke that it's Alex, but we have conflicting evidence

anOKsquirrel

what evidence?

Anonymous

At one point Alex claimed it, but alex-is-wrong, so...

Nathan Merrill

@MartinBüttner that's a rotation of mine

Martin Büttner

oh, right

Nathan Merrill

3:12 PM

010
101
010

Martin Büttner

hah, neat :)

Anonymous

@NathanMerrill The inverse of that (except the middle square) also works, I believe

Martin Büttner

@Mego yeah, because it's a rotation of the trivial solution

Anonymous

True

quintopia

@Mego any circle on a square grid should work

Anonymous

3:13 PM

So either it's a circle or one of the two tetrominos who don't have a side of length 3

Anonymous

(square and z)

quintopia

01110 10001 10101 10001 01110

Martin Büttner

ctrl+k

(for multiline + code formatting)

anyway, your pattern contains 111

quintopia

Yeah

Anonymous

So circles only work on 3x3

Anonymous

3:16 PM

With 4x4 you get diagonals

anOKsquirrel

yeah

quintopia

So how to do multi-line on mobile?

Anonymous

Anonymous

Interesting

VoteToClose

Question: can I post a non-competitive answer if it's interesting?

anOKsquirrel

3:17 PM

there's a meta on that i think

Not the same, but meta.codegolf.stackexchange.com/questions/7352/…

quintopia

This discussion males me want to play Unruly on Tatham's Puzzle Pack

Anonymous

@VoteToClose Non-competitive how?

Martin Büttner

^

if it outright ignores the winning-criterion, no

if it just happens to be in a non-competitive language or simply worse than the best answer in the language (but still golfed, say), then that's fine

@Mego and invalid ;)

VoteToClose

I wrote a quine for the "output the PPCG logo", but for when it was a popcon. I've since then still made it a quine that still follows criteria, but golfed it down a bit.

Anonymous

@MartinBüttner That was me testing the 4x4 circle

anOKsquirrel

3:20 PM

@Mego My language keeps not wanting to use Unicode and I don't know why :/

Anonymous

@VoteToClose I don't see an issue with that. I mean, people use Java for answers.

VoteToClose

Oh, hey, the pinned star-bait message is gone! :D

Anonymous

@VoteToClose for now

VoteToClose

D:

Oh, dammit, new criteria makes my quine not follow the guidelines. -.-

I always spend time on questions, then realize I'm doing it wrong.

Anonymous

@anOKsquirrel Have you tried turning it off and on again?

anOKsquirrel

3:23 PM

@Mego yeah, and duct tape

Anonymous

@anOKsquirrel Go for the wd-40, then

Martin Büttner

@VoteToClose with that particular question you only have yourself to blame for wasting time on a bad challenge ;)

anOKsquirrel

@Mego That too. I even used glue

Anonymous

On a serious note, got a github link or pastebin that I can look at?

anOKsquirrel

yes, I'll make a pastebin. the GH version is the current stable one

VoteToClose

3:24 PM

Interestingly, I accidentally pushed it at some point. See: github.com/VTCAKAVSMoACE/Vitsy/blob/master/examples/PCG

Anonymous

Github is preferable

anOKsquirrel

@Mego yeah, but it's all on master and such :/

Anonymous

@anOKsquirrel So?

quintopia

0101
1100
0011
1010

anOKsquirrel

I dunno

i'll make a gist

VoteToClose

3:25 PM

Why are we posting binary?

anOKsquirrel

2

Q: Maximal tiling without any 3-in-a-rows

You are given an arbitrarily large grid, where each square can either be off or on (think Game-of-life type board). You need to tile such a grid to maximize the number of "on" squares without there being any 3-in-a-row of "on" squares. A 3-in-a-row can be horizontal, vertical, or diagonal. 3-i...

that's why

quintopia

Because it's an interesting 4x4 solution, that is inverse-quarter-turn-symmetric

anOKsquirrel

gist.github.com/an-OK-squirrel/…

quintopia

Actually it demonstrates the relation to ellipses

Martin Büttner

@NathanMerrill how many valid 5/9 non-wrapping blocks are there, and we can tile the plane with them?

quintopia

3:29 PM

Since it's identical to
1100
1010
0101
0011
you can see the two interlocking boats

anOKsquirrel

@Mego gist.github.com/an-OK-squirrel/…

quintopia

Oh wait

Martin Büttner

@quintopia are we talking about different problems?

quintopia

Invalid

Martin Büttner

right

VoteToClose

3:30 PM

Secret quotes + images = a bad time

quintopia

But the original wasn't I just translated it wrong

Martin Büttner

no, you translated it correctly

if you tile the original you also get diagonals

Optimizer

okay, I ruined the binary number.

VoteToClose

>! Does this work in chat?

No, it doesn't. :c

Optimizer

spoiler?

VoteToClose

3:32 PM

Yeah, spoiler quotes and images don't work together.

The image just suddenly appears when you highlight over it instead of a smooth fade.

Heh, I just noticed this in the edits for the PPCG logo question:

codegolf.stackexchange.com/revisions/64763/4

Anonymous

@anOKsquirrel gist.github.com/Mego/bf8908ead49b4c51d9c0 works fine for me. I'm guessing the issue is with terminal input - try cating from a file

anOKsquirrel

It takes a file name, not a program

VoteToClose

Can we all give this answer some love:

1

A: Sprocket Science: Animating a Chain Drive System

C# Not golfed at all, but works (I think) Uses Magick.NET to render gif. using System; using System.Collections.Generic; using System.Drawing; using System.Drawing.Imaging; using ImageMagick; namespace ConsoleApplication1 { class Sprocket { public float x,y,r; public bool clockwise; public do...

It's the only answer and it's so fannncy.

Anonymous

$ cat test.py && echo && echo && cat test.py.txt && echo && ./test.py test.py.txt
#!/usr/bin/env python3

replace_chars = {
    'à': ' 0'
}

def char_replace(code):
    result = ""
    for char in code:
        if char in replace_chars:
            result += replace_chars[char]
        else:
            result += char
    return result

with open('test.py.txt',encoding='utf-8') as f:
    print(char_replace(f.read()))

àbcd
 0bcd

anOKsquirrel

ohh, I forgot the encoding part in open

Anonymous

3:43 PM

Wow I expected that to be shrunk

Anonymous

Yeah it matters

Anonymous

Unless your locale encoding is utf-8 (hint: it almost certainly isn't)

Martin Büttner

@Mego Nathan got an answer bringing the upper bound down to 7/12

anOKsquirrel

@Mego lemme try again, without file io

Anonymous

@MartinBüttner Neat

Anonymous

3:47 PM

@anOKsquirrel perlgeek.de/en/article/set-up-a-clean-utf8-environment

Anonymous

You may find that helpful

anOKsquirrel

welp, I can't see why it would make a difference (because I'm dumb)

Anonymous

Hmm?

anOKsquirrel

I can't tell if it's file IO or my code

Anonymous

It's probably the file IO

Anonymous

3:49 PM

Make sure you always specify the encoding

anOKsquirrel

hm

Anonymous

Otherwise it'll assume something like Latin-1, and do one char per byte

Anonymous

Rather than recognizing and handling multibyte sequences

VoteToClose

StandardCharsets.UTF8

anOKsquirrel

@Mego I specified the encoding, and I tested it with the -i flag. Doesn't seem to work right

Anonymous

3:51 PM

@anOKsquirrel I don't know what the -i flag is

anOKsquirrel

@Mego interactive

Anonymous

Oh

anOKsquirrel

gives a shell after program runs

VoteToClose

So, for this question, how would we scramble MC code?

16

Q: Find the Interweaved Source Codes (Cops)

This is the cops' thread. For the robbers' thread, go here. Introduction For this Cops/Robbers challenge, the cops will write output-producing programs and interweave them together. It is the robber's job to pick apart the cops' programs to produce the desired outputs. Cop rules The cops may ...

code-golf cops-and-robbers

anOKsquirrel

Nope! It's my terminal. I feel really dumb now :/ I used IDLE to check

@VoteToClose Minecraft you mean?

VoteToClose

3:52 PM

Yes.

anOKsquirrel

huh

Nathan Merrill

I have a really good idea for the cops

take an interpreted language that prints errors to stdout

have one program produce a syntax error

and interweave it with a normal program

ah wait "program must not contain errors"

nevermind

anOKsquirrel

Idea: for MC input, use signal strength. 0-15 = 0-F

Martin Büttner

@NathanMerrill his proof for 7/12 is the same as yours for 6/9

(and the tile we've used to prove 6/9 is also assumed to be non-wrapping)

Nathan Merrill

yeah, I misunderstood

VoteToClose

3:56 PM

@anOKsquirrel I use command blocks, which means I have to interweave source code and block position.

anOKsquirrel

@VoteToClose hmm

@Mego I'm on Wandoze, Locales: generation makes no sense to me

Anonymous

@anOKsquirrel Don't use IDLE :P

anOKsquirrel

@Mego I use gitbash

Anonymous

Cygwin

anOKsquirrel

same thing, right?

Anonymous

3:58 PM

Ahahahahahahah

Anonymous

Ahahahahahahahahahah

Anonymous

No

Anonymous

Anonymous

(That's IDLE with 2.7, but it's the same for 3.x)

anOKsquirrel

it works in IDLE, but not in git bash.

Anonymous

4:00 PM

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

Ant Wars king-of-the-hill Parts of this challenge are based off of Ant Queen of the Hill Contest. Objective To conquer the ants of the world ... or have the biggest army of ants. To do this, you start with a single queen. The queen can create worker ants by using food gathered by itself o...

Anonymous

^^ That would be why

Anonymous

Go away sandbox you're in the way of my carrots

2

anOKsquirrel

lol

YES THANK YOU

Anonymous

4:01 PM

That's what Cygwin looks like

anOKsquirrel

i know

THANK YOU YES

Anonymous

Use it

anOKsquirrel

:D

I did

Anonymous

And it worked?

anOKsquirrel

YES

Anonymous

4:02 PM

Good :)

Anonymous

Let this be a lesson to you: one cannot program with bash alone

Anonymous

You need a full POSIX environment

Anonymous

Because POSIX is da bomb

anOKsquirrel

k

Martin Büttner

@NathanMerrill I can't seem to fit 10 into 4x4 either. It's probably not too hard to prove, but an exhaustive search with some code should be quickest.

New Sandboxed Posts

4:09 PM

0

A: Sandbox for Proposed Challenges

Output the Current Time [CATALOG] code-golfdatetime Challenge You must output the current time continuously (until cancelled by an interrupt), once every second, by any of the following means: It must be in 24-hour or AM/PM format. If it is the former, it must be spaced out with colons (i....

Martin Büttner

I wonder you could find an analytic solution for the upper bound in a 3xN matrix, and then just let N->infinity.

randomra

for a 3xN you only have to keep track of the last 2 columns, so you can do an exhaustive search

or do you want to tile with it?

Martin Büttner

@randomra no

@randomra I'm not following that

Dennis

@randomra Thanks. :) How does 1+/@,0=i.|] work? I can't seem to figure out how 1+/@, is parsed.

randomra

@Dennis ((+/)@,)

adverbs & conjunctions are LTR, with the same priority

Dennis

4:18 PM

Oh, right. Thanks!

I always have trouble combining +/ with the rest of my train.

Anonymous

choo choo

randomra

if it is on the right, you need parens

@MartinBüttner you can find all optimal solutions for 3xk (k=1..N) in O(N) by greedily keeping the best entries from the 3xk's with distinct last 2 rows

New Main Posts

1

Q: Golf yourself a beer

It's friday! Which means it's time for beer! Sadly though, today we will be golfing beer instead of drinking it. :( Challenge Output a beer and drink it. The amount of sips you take changes your output. Sips Your program should take one input string. This string can solely consist out of conc...

code-golf ascii-art

randomra

but I guess you know that, just didn't understand what I tried to say

Martin Büttner

oh I see, I hadn't thought of that, but I did think about how to reuse the previous results

SuperJedi224

4:27 PM

Hey guys

VoteToClose

Hello. :D

orlp

yo is one of the math geeks here

VoteToClose

Oh, @El'endiaStarman!

Anonymous

I'm here

orlp

I'm trying to explain to myself why shuffling a latin square first by rows then by columns is not a way to uniformly generate random latin squares

New Main Posts

4:39 PM

2

Q: Title Keywords in Context

This challenge is based on a problem described in D. Parnas, On the criteria to be used in decomposing systems into modules, and elaborated upon in J. Morris, Real Programming in Functional Languages. Write a program or function which takes a list of book titles from stdin or as an argument, in ...

code-golf string sorting

orlp

when I look at the wiki: en.wikipedia.org/wiki/Latin_square

the number of valid latin squares of N = 5 is 161280

while 5!^2 (the number of possibilities from two permutations) is 14400

so clearly it can't be uniform - it can't even generate all possible latin squares of size 5

but I fail to see why

Martin Büttner

@randomra actually, I'm not sure it's necessarily true, that an optimal 3xN solution builds on an optimal 3x(N-1) solution.

orlp

@MartinBüttner what problem?

Anonymous

@orlp I'll ponder it in the shower

Martin Büttner

Nathan's binary matrix problem. Scroll up a bit, I'm on mobile right now ;)

orlp

4:43 PM

"given an arbitrarily large grid of on/off switches (think game of life), what pattern of switches will maximize the number of "on" switches without there being exactly 3 "on" switches in a row?"

?

Anonymous

Yep

orlp

is it rows only?

or columns as well

Sherlock9

I've got another problem idea and it's the Josephus problem again. Given the size of the circle, the steps to elimination, and p your position at the start, either determine when you are eliminated (by saying if you are the something-to-last eliminated or your the something-th survivor) or would you survive if e people were eliminated from the circle

Anonymous

Horizontal, vertical, diagonal

Anonymous

And >= 3 is forbidden

orlp

4:44 PM

everything on

done

Anonymous

That's >= 3

orlp

only exception is for n = 3