The Nineteenth Byte

DJMcMayhem

00:11

Boom. First challenge I've posted in over 100 days :)

Adám

An Illustrated Guide To Formatting Code In Chat

New Main Posts

1

Q: Tell me how to flop

As computer scientists, you're probably all familiar with the basic list operations of pop and push. These are simple operations that modify a list of elements. However, have you ever heard of the operation flop? (as in flip-flop)? It's pretty simple. Given a number n, reverse the first n element...

Conor O'Brien

00:35

536 9}0 4-0 2-18 9}22.`9{.><0 32 9}303.79?><-+8}9}8{9{><0 56 9}303.104?
><-+8}9}8{9{76 9}481.9{.><-+89 9}195.95 9}22.101 9}195.9{.><-+114 9}195
.8}9}8{9{>129 9}22.8}9}8{9{141?170.<8}9}8{9{-8}9}8{9{165 9}195.1-9{.<><
-+8}9}8{9{189 9}195.9{.9{.0 8}9}8{9{-9{.>8}>8~>~0~<<<228 9}285.8}236 9}
323.8{244 9}361.9{.>8}>8~>~0~<< <266 9}303.8}274 9}323.8{282 9}361.9{.-
292 9}421.1 300 9}323.9{.-310 9}421.0 1-320 9}323.9{.-330 9}421.334?340
.><-9{.1+9{.353?><-9{.><-1+9{.365?371.><-+383.><-+383?><-9{.><-1+9{.399

signed integer division in a new language of mine

iPhoenix

Oh goodness, that's fun. (And that's not entirely sarcasm)

Leaky Nun

00:53

CMC: write a program to determine if a given brainfuck program terminates when given no input

mudkip201

...

Dennis

lol

mudkip201

Is the new main post basically pancake sorting?

iPhoenix

@mudkip201 No, not really.

totallyhuman

@NewMainPosts so flop till you group

mudkip201

00:56

ah. I misread

lol

You /could/ pancake sort

but you don't have to

totallyhuman

I can't think of a good way to approach this

iPhoenix

I'd consider your interpretation of what it said to be in the top 50% of interpretations of that title.

mudkip201

@totallyhuman pancake sorting would work afaict

iPhoenix

Anyone who did that would certainly get my upvote.

HyperNeutrino

hi I'm switching to a new computer; any recommendations of which Linux Mint edition to install (Cinnamon, MATE, Xfce, KDE)?

my current computer's edition is KDE so I'm probably going to just install the same edition because I'll probably be more used to it but idk

totallyhuman

01:04

kde plasma is really cool tho

Dennis

I haven't tried Cinnamon since I don't use Mint, but KDE would be my top choice among the other three.

HyperNeutrino

hm okay thanks for suggestion

I'm probably going to choose it just because I'm already using KDE on my old computer, so yeah I'll go with that

totallyhuman

xfce and mate are really only for computers that can't handle much heavier

HyperNeutrino

oh okay.

this computer's currently running windows 10 and it looks so unfamiliar because I haven't used any windows systems in forever :p

totallyhuman

mate's pretty good for raspis for example

@HyperNeutrino not even in school?

Conor O'Brien

01:07

@HyperNeutrino install windows 7

totallyhuman

my school torments us by making us use Windows

Conor O'Brien

what don't you like windows? (also, how many people at your school are actually "tormented" by windows other than you XD)

totallyhuman

well over exaggeration but I'd be much happier without :P

also nobody else in my school cares but whatever :P

Downgoat

@HyperNeutrino macOS

Conor O'Brien

at least windows 10 is making some steps towards sanity :P

HyperNeutrino

01:10

@totallyhuman no I use my chromebook in school (chrome OS is worse but the school board decided to just give everyone in high school a chromebook (yet they can't buy us working AC...))

^^^/o_o

totallyhuman

there's this kid who uses an originally Windows laptop with Linux installed on it... and he has a macos theme ಠ_ಠ

HyperNeutrino

oh god I don't have anything set up on this computer. ykw i'm not even going to bother to fix that

totallyhuman

@HyperNeutrino do you have a compsci class?

HyperNeutrino

yes but it's an online course

the school has several actual computer labs just that we don't use them that much because everyone conveniently has a chromebook to use

why is all of the text in the chat message box now in italics....

... I just tried to do chrome://downloads on MS edge

totallyhuman

5/7

HyperNeutrino

01:14

lol

uh

how do you view current downloads on MS edge

solution: download a second item, click "view downloads", and see which button is highlighted when the downloads pane is open :p

totallyhuman

ಠ_ಠ

tfbninja

02:02

@mudkip201 Can you possibly explain exactly what Ụ does in Pyt? I'm trying to use it to solve this challenge, but it doesn't seem to be doing what I thought it did.

@HyperNeutrino Why use MS Edge when this exists?

totallyhuman

cause he's on a factory installation of Windows

and he's about to wipe it off the face of his hard drive

user202729

The on hold NMP first test case seems suspicious...

(the only difference between the NMP and the problem listed there is that the NMP optimizes for the sum and the problem in the book optimizes for the count)

ATaco

I probably need to write a proper tutorial for Funky.

user202729

3

Q: How many draws are there in Quarto?

Introduction This challenge is similar to Project Euler problems. I came up with it because I was playing a deceivingly simple board game and couldn't come up with an efficient solution to answer a simple question about its mechanics. Quarto is a fun variant of 4 in a row. It is played on a 4 b...

game permutations fastest-code board-game

How can hardcoding be prevented ^?

Nick Clifford

02:20

so I'm adding some hashing functions to Ohm (MD5, SHA1, SHA256, SHA512), and I'm trying to figure out what characters to assign them to. anyone have any suggestions? I want to keep them next to each other in the code page (github.com/nickbclifford/Ohm/blob/master/code_page.md)

Conor O'Brien

which are available?

Nick Clifford

pretty much any, since they will have a · prefix instead of being single-character

PhiNotPi

Right now I'm picking up a radio station with my headphones... kinda interesting.

ETHproductions

I know, right? I was amazed the first time I found I could do that with my phone

Dennis

Do phones still do that?

ATaco

02:24

I think so.

Nick Clifford

TuneIn Radio exists (for iOS anyway)

Conor O'Brien

@NickClifford ¹ ² ³ ⁴ seems pretty ok

Nick Clifford

alright, thanks

I like that too

PhiNotPi

I've never had a phone do that, pretty sure it's my headphones themselves (since adjusting volume on my laptop doesn't affect it).

ATaco

Have you considered that tab may haven not been the correct separator there?

ETHproductions

02:24

@PhiNotPi That's... even more interesting

Nick Clifford

he was probably directly pasting from the code page document

Conor O'Brien

I was indeed

@ATaco did you consider that programmers are by nature lazy

ATaco

I did not.

Pavel

@Dennis All phones have an fm radio chip, however on many it comes pre-disabled for your convenience.

ATaco

And now that i think about it, that sounded hostile. I am sorry if it seemed that way.

PhiNotPi

02:26

@ETHproductions Can't tell if it's either the chips inside the headphones, or the 6-foot cord that connects it to my laptop.

user202729

Can anyone take a look at my last messages about the on hold challenges on main? ...

ATaco

It's pretty hard to prevent Hard Coding.

But Hard Coding is a standard loophole.

Conor O'Brien

@ATaco good to know, thanks

user202729

Often, this vulnerability is an indicator of a dumb question... — boothby Mar 7 '14 at 19:37

Dennis

@Pavel Weird. Not that I care, as I don't listen to FM radio anyway...

user202729

02:29

It's not clear what can be hardcoded and what can't.

Pavel

@Dennis npr.org/sections/alltechconsidered/2015/04/16/400178385/…

mudkip201

@tfbninja Ụ Takes an array X, and if there are multiple occurrences of an element in it, it removes all but one of them

HyperNeutrino

ok so I managed to boot linux from a USB but Ctrl-Alt-F7 is frozen and all of the 6 TTYs aren't useful because I can't log in because there are no accounts

Dennis

Not even root? Hard to believe.

HyperNeutrino

well idk the password¯\_(ツ)_/¯

even if the account exists

Conor O'Brien

02:35

Would this be a good main challenge? compute divmod(n, 10) using only addition and subtraction, where calls of the operators increase score. the idea would be to use the least operator calls to win

user202729

(password) Try root ?

I don't know.

HyperNeutrino

i've tried root,<nopassword> and root,root

Dennis

Or the empty password.

ATaco

@ConorO'Brien Hard to restrict.

Conor O'Brien

how so?

Pavel

02:36

@HyperNeutrino Which distro is on that liveusb?

user202729

Read the docs of whatever you copied to the USB?

HyperNeutrino

linux mint 18.3 kde

Dennis

Or mount it elsewhere and edit /etc/shadow.

ATaco

What's "only addition and subtraction" mean? Can I not use any functions that mutate numbers? How are they defined?

Conor O'Brien

well that would be ironed out. it's not really much different from proof-writing challenges, I'll specify specific forms in which code can be written

user202729

02:37

@ConorO'Brien You may want to restrict to one language and make it atomic code golf.

Pavel

@HyperNeutrino 0/10 for distro 10/10 for de choice

HyperNeutrino

o?

ATaco

Yeah, you can't be language inclusive and restrictive.

HyperNeutrino

ohhhhh

mint,<nopassword>

mudkip201

@tfbninja You don't need to use Ụ

Conor O'Brien

02:38

@ATaco would it be easier if I designed a language and forced people to use that

ATaco

Technically, yes.

HyperNeutrino

i still can't really do anything though

Pavel

@HyperNeutrino Congrats, you are now in an fn terminal. What do now?

Ninja'd

user202729

Try to read the docs, again.

Pavel

You can try to install from the command line

user202729

02:39

Is there anything? Try ls?

ATaco

@ConorO'Brien Alternatively, force people to use Brainfuck. But that would look, uh, bad.

user202729

There may be install.txt or something...

HyperNeutrino

it looks like a normal user's file system

ATaco

Then again, Do X without Y challenges usually aren't great.

Pavel

I reccomend /sbin/shutdown -r 0

user202729

02:40

So... you can't ctrl alt f7? Why?

Conor O'Brien

@ATaco what are you talking about

user202729

@HyperNeutrino Try Alt+Right.

ATaco

Usually.

HyperNeutrino

@user202729 i can but it just doesn't let me do anything. it's a blank black screen with a frozen underscore (cursor) and my mouse cursor

:D IT LOADED

user202729

I still don't want to reopen quarto.

Too many downvotes...

HyperNeutrino

02:42

ok so I have a desktop now but KWin crashed which is not very helpful lol

and i can't open a file manager

Dennis

Burn the flash drive and download another distro.

HyperNeutrino

what distro would you suggest

also it finally loaded it's just extremely slow because USB

user202729

...... too bad ... Can't you install it?

Seriously, "no hardcoding" is really unclear. Anyone?

Pavel

@HyperNeutrino Fedora or OpenSUSE

Dennis

^

HyperNeutrino

02:45

hm ok

still KDE though?

Pavel

Yeah

HyperNeutrino

ok

Leaky Nun

2 hours ago, by Leaky Nun

CMC: write a program to determine if a given brainfuck program terminates when given no input

HyperNeutrino

i looked up "fedora" and all i get is the hat... lol i forgot about that

user202729

@HyperNeutrino "ṢU$" is "NÞ", saves 1 byte.

@LeakyNun Impossible.

HyperNeutrino

02:46

how so

Pavel

I like OpenSUSE more generally speaking, but last time I installed it I managed to somehow get zypper (SUSE package manager) to not work unless the flash drive I used to install from was plugged in to the same port it was plugged into during installation.

HyperNeutrino

brainfuck has no random

user202729

(save 1 byte for this)

HyperNeutrino

@Pavel ?? huh that's weird.

user202729

Because it's equivalent to the halting problem? BF is TC?

Pavel

02:47

Yeah, still not sure how that happened.

HyperNeutrino

would ppl recommend fedora or opensuse keeping in mind i hardly have any idea what i'm actually doing :p

i guess

Leaky Nun

@HyperNeutrino it is the halting problem

HyperNeutrino

lol

Leaky Nun

any such program can be encoded into brainfuck

Pavel

You'll probalby find it easier to get help for Fedora, it's more commonly used.

I'd go for Fedora

Leaky Nun

02:48

and do something on the encoded program, and get a contradiction by feeding it into itself

HyperNeutrino

@user202729 oh okay thanks [not going to change though]

okay, thanks

fedora workstation?

Pavel

Yes

HyperNeutrino

ok

Pavel

You want the fedora media writer

user202729

Also it need a œ^J to work.

(I forgot about ÐṀ, I used ÞṪ)

Pavel

02:50

@HyperNeutrino If you do go for Fedora, I reccommend installing Discord from here, since I've tried like 5 other methods that didn't work. sudo dnf copr enable tcg/discord && sudo dnf install Discord-installer will install Discord (it'll take a few seconds after the package finishes installing for the installer to do magic) and then keep it automatically updated at all times.

HyperNeutrino

oh cool, thanks.

also what was the thing i'm meant to run immediately after installing again? sudo dnf remove PackageKit?

Pavel

Yes exactly

Some things depend on it. You don't need them.

HyperNeutrino

oh okay

wait so fedora media writer am i supposed to install that after installing fedora

Pavel

RPM Fusion provides repos for non-free software like Steam.

HyperNeutrino

ok

Pavel

02:52

@HyperNeutrino No, that's just something to create the liveusb

HyperNeutrino

oh okay

Dennis

The problem is, now that the output doesn't depend on an input, it is very difficult to draw a line between what is allowed and what is forbidden. Sure, print <solution> is "hardcoding", but you'll have to specify exactly what information can be stored in the source code and what cannot. This is very difficult to get right; it would be much easier to switch back to the generalized challenge. — Dennis ♦ 2 mins ago

Not much more we can do.

@Pavel Is your dd broken? :P

user202729

Thanks. But...

Pavel

@Dennis My dd is just fine, but in my experience dd is much more effective at nuking your hard drive by accident than Media Writer.

user202729

even for the generalized challenge, someone can still hardcode something.

Because there are incredibly few test cases...

... why are the specs necessary? I don't understand... faster solutions are still faster, right? Or not?

Dennis

02:58

Not at all. Different CPUs have different instruction sets and different number of CPU cores. You also need to know how much RAM you have available.

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