The Nineteenth Byte

Nobody Needs Names

11:00

yes indeed. gotta go o/

hello

bye

Sandbox Posts

0

A: Sandbox for Proposed Challenges

Fill a matrix with another Given two multidimensional, rectangular arrays such as: [ [1, 2], [3, 4] ] [ [1, 2, 3], [4, 5, 6], [7, 8, 9] ] Your challenge is to repeat the smaller matrix to fill the larger. For example, with the above, we expand it infinitely: 1 2 1 2 ... 3 4 3 4 ... 1 2 ...

PyGamer0

@Bubbler I would agree :P

~~nah the future is wellscripted~~

once i figure out parsing

Nobody Needs Names

11:33

a ha ha

Nobody Needs Names

11:44

This chat room is abandonned. The real chat room is here:

The Sand Trap

Room for discussions off-topic to CGCC (on-topic discussions s...

caird coinheringaahing

12:03

CMC: Given some black box function f : Z × Z → Z, output the Fibonacci sequence, but using f instead of +. Standard sequence rules

I have 3 bytes in Jelly, taking n and outputting the nth (0-indexed) element

thejonymyster

@NobodyNeedsNames I've thought of that but that seems too typical. I want to get the most use out of it :P maybe it should do something variable, like time dependant? :PP

mathcat

@cairdcoinheringaahing like f=lambda z:z**2?

caird coinheringaahing

@mathcat No, a function that takes in two integers and outputs one

mathcat

ah

lyxal

that is, a single integer, not the literal 1 lol

it'd be a tad easy if it always returned 1 :p

Adám

12:26

@cairdcoinheringaahing APL, 17: {1≥⍵:⍵⋄⍺⍺/∇¨⍵-⍳2} Try it online!

thejonymyster

12:56

@cairdcoinheringaahing js, 63 bytes

not fantastic but it's functional :P

Jo King

@emanresuA clicks on link, sees 16 flags. oh boy

thejonymyster

wait im a genius

58 bytes (i,f)=>{e=[1,1];while(i--){e.unshift(f(...e))}print(e[1])}

Jo King

while(b){x} can be while(b)x;

thejonymyster

i keep forgetting :P thats -1 ty

Jo King

ah, and you can switch to a for loop and put the e initialisation at the start to save another

thejonymyster

13:05

ah i had a feeling i could use a for loop somehow but it wasnt clear to me how

oops i ah'd your ah

but yeah i keep forgetting basic js stuff im rusty

Jo King

a for loop is always equivalent or shorter than a while loop

thejonymyster

right

PyGamer0

@lyxal @UnrelatedString yall will love this colorscheme :P

Wheat Wizard

@pxeger Ok here's my records for the n <= 10. Brownie points for anyone who can beat them.

00 00: []
01 01: [0]
02 02: [1,0]
03 03: [1,1,0]
04 06: [2,0,1,3]
05 08: [4,0,1,3,2]
06 10: [5,2,0,1,4,4]
07 12: [6,4,0,1,4,2,5]
08 14: [7,5,2,0,1,5,4,6], [4,6,1,4,2,0,1,7]
09 19: [8,0,1,5,2,5,1,7,4]
10 23: [9,4,0,1,5,2,6,1,8,8]

PyGamer0

@cairdcoinheringaahing how do you input functions in jelly.

thejonymyster

13:20

CMC: do irreparable damage to the user's computer

PyGamer0

@thejonymyster VTC as off topic

thejonymyster

fair enough :P

mathcat

@thejonymyster * user angry noises *

Jo King

@thejonymyster lyxal's probably the closest to me, i'll grab my hammer and start walking

lyxal

see you in a few hours

or days

thejonymyster

13:23

what have i set into motion...

PyGamer0

@lyxal but LDW is tomorrow

Jo King

🔨o

8

lyxal

idk how fast you walk and if you'd give up on walking and just get an uber

thejonymyster

o/

lyxal

so yeah see you soon

thejonymyster

13:23

almost overwrote some work data with "o/"

like yeah goodbye data

lyxal

@thejonymyster yikes

thejonymyster

probably would have been fine but let this be a lesson to you multitaskers: Ensure you know where your cursor lies...

(before you order extra fries?)

caird coinheringaahing

@PyGamer0 Put the function kn the previous line, and use ç/Ç

PyGamer0

@cairdcoinheringaahing oh yeah... but is that allowed?

thejonymyster

that's how functions work in jelly yea

p sure you can access more than just the previous line too so its not like a hack its just like

every line defines a function, the main link gets ran

... wait hm

i totally missed the point of your question :P

that seems potentially like it could be construed as not being a function input

(im guessing thats what you meant to get at )

lyxal

13:36

→ 31 off-topic related messages moved to Off-Topic TNB

Nobody Needs Names

anyways i'm done

PyGamer0

i wish i ran for RO :p

Nobody Needs Names

and gotta go o/

PyGamer0

@lyxal thanks

Nobody Needs Names

thanks

mathcat

13:37

@PyGamer0 get 10k rep first :P

thejonymyster

@NobodyNeedsNames never do that again

lyxal

^

thejonymyster

@mathcat ez just do bounties

PyGamer0

@cairdcoinheringaahing if i understood it correctly then this in flax

mathcat

@thejonymyster oh yeah

thejonymyster

13:38

ive got 3 500 bounties up rn :P go do these

Nobody Needs Names

ok

thejonymyster

CMC: given two positive integers, output their greatest common multiple

caird coinheringaahing

@PyGamer0 Yes. One accepted way to take functions is as a named function

thejonymyster

wait really? can i use that to golf my js or is that not an option since i can take the function as a direct input

caird coinheringaahing

Either is acceptable I believe

mathcat

13:46

@thejonymyster Vyxal, 1 byte: ġ

thejonymyster

@mathcat bzzt

mathcat

bzzt what

thejonymyster

read it again :P

mathcat

oh lol

can't delete it now

thejonymyster

ok no more joke cmcs i promise

is it ever good practice to not write up a code breakdown? (besides for like cnr or whatever)

caird coinheringaahing

14:09

@thejonymyster Jelly, 1 byte: Try it online!

Takes input via stdin, but works even if you don't provide any

thejonymyster

wow psychic programming

mathcat

Vyxal, theoretical 3 bytes

thejonymyster

it'll find it at some point im sure of it

mathcat

hopefully

thejonymyster

challenge inspired by me struggling to remember what "GCF, LCM, LCD, GCD" all mean

sadly i couldnt just send "GCM" since that apparently means "greatest common measure" which apparently means the same thing as greatest common divisor (??)

pondering alternate ways of thinking about talk interpreter, was trying to see if any logic gate could be repeatedly applied on each successive bit

dont think there could be, but the resulting table was interesting

top * left

    0 1 A B C

0   A C 0 0 1
1   B A 1 0 1

lyxal

14:28

→ 2 kilolitres of milk moved to The Nineteenth Bakery

thejonymyster

quality of a code golf question can be defined as "how many 0 or 1 byte answers it receives" where more is better

TKirishima

What do you mean thejonymyster

And sorry for posting a question for that, I didn't know this existed.

lyxal

→ 9 messages moved to Off-Topic TNB

thejonymyster

@TKirishima i just meant it is possible that someone has asked it, so before you ask in meta, try searching for it

but it is also possible that it hasnt been asked

TKirishima

I meant, what do you mean by "quality of a code golf question can be defined as \"how many 0 or 1 byte answers it receives\" where more is better"

thejonymyster

14:32

oh sorry that was a joke :P

the opposite is more likely to be true

TKirishima

oh okk

mathcat

@thejonymyster except the challenge is from 2008 or earlier :P

thejonymyster

off the top of my head id probably say "adheres to standards well, not trivial, provides lots of possible strategies" but also that last one is very hard to do intentionally lol

and also i personally am biased to trivial challenges :P becausei am bad

TKirishima

Yes, it's better to have challenges where several solutions are possible at first sight. After the thing is that it's not necessarily easy to do this intentionally even it can be quite hard, I think. But thanks :)!

thejonymyster

ok i think i remember, in meta theres a question saying what not to do

what not to do

TKirishima

14:37

Thank you !!! :D

thejonymyster

some of these are kind of specific, but trying to think of what the opposite would be helps lol

like "Multipart challenges with unrelated sub-tasks" being bad makes me think "a well focused challenge" is good

so if anyone's making a list, jot that down :P

mathcat

@DLosc Is there a pip chatroom?

caird coinheringaahing

@thejonymyster More is worse, IMO

thejonymyster

whaaaaaat :P

yeah i was goofing, don't worry :)

caird coinheringaahing

@TKirishima I'd recommend reading through our Welcome page, that has a lot of good info for new users

thejonymyster

14:48

I can't lie though, I really love seeing the retina 0 byte get used :P

feel like a marvel nerd when heroman shows up in the avenger credits. its like

omg the retina 0 byte program <3_<3

i mean i guess its cause like, it's not the same as some random "oh this lang has a builtin", its a logical feature of the language and it just happens to be useful based on how certain problems are defined lol

you all knew this though

Adám

@thejonymyster APL: ∨

thejonymyster

that's greatest common divisor :P sorry i was a prankster back then, i've changed my ways

PyGamer0

15:05

> greatest common multiple

Wezl oOvOo

> back then

thejonymyster

it really feels like so long ago

Wezl oOvOo

alright let's see whether you're lying

thejonymyster

0:) <- innocent

Adám

@thejonymyster APL: ⌊/⍬

Wezl oOvOo

15:08

when you see dQw do you immediately (a) run away screaming! (b) feel a sense of kinship with the poster and click it out of respect

thejonymyster

i'm actually not sure it's a rickroll until i hear the chorus

Wezl oOvOo

unclear answer

PyGamer0

@lyxal i used vyxal to explain math to my brother :P

pxeger

yay

PyGamer0

congrats!

pxeger

15:22

I'm coming for you, lyxal

PyGamer0

just 1391 more rep :p

Seggan

anyone remember how to disable scrolling when switching between virtual desktops?

PyGamer0

desmos.com/calculator/hv6hov1w8b

Radvylf Programs

15:44

Hi guys it's Radvylf, the inventor of math. I'm introducing lcd today, short for least common divisor, which gives you the smallest number that's a divisor of both its inputs. Also is that the syntax for multiplication and division has switched, so putting 2 on top of a horizontal line and 3 under it means 6, and 2x means 2 divided by x.

thejonymyster

@PyGamer0 what exactly is this

Wezl oOvOo

@RadvylfPrograms at least tell me you used semantic versioning and made this a new major version :P

Radvylf Programs

No no no, this is just a minor patch, 2.21.1. In 2.22.0, we'll see long-awaited changes like the removal of trigonometry, and a new integer that breaks the fundamental theorem of arithmetic.

Wezl oOvOo

at least the british people will be ok because they don't use math :P

pxeger

yeah, maths was forked from math somewhere around version 2.8.0

mathcat

15:57

I reckon I'm a fork too.

I just don't remember my version anymore

Sandbox Posts

16:46

0

A: Sandbox for Proposed Challenges

Seeing the queen's lasers In chess, the queen piece can see arbitrarily far in each cardinal and intercardinal. What does this mean? Well, I'll show you with an ASCII drawing: \..|../ .\.|./. ..\|/.. ---Q--- ../|\.. ./.|.\. /..|..\ It means the queen (notated as Q) can see along these lines (not...

mathcat

17:47

Is there a depth-sort of thing for numbers? eg. 1,4 => 0; 2, 3=>1 or 1,6 => 0; 2,5 => 1; 3,4 => 3;

oh wait nvm

actually do mind

minus the half and absolute doesn't work

thejonymyster

what does that have to do with sorting?

mathcat

depth

it's like when n=4, how close the numbers are to 1.5

2 and 3 are the closest, then 1 and 4

@mathcat I mean 2.5

I guess i could just add 0.5 to the half of n and then to the absolute value thing

no that wouldn't work too

the closer, the bigger the number should be

Seggan

18:26

@RadvylfPrograms do you have a 2.22.0 alpha build?

i want that removal of trigonometry

thejonymyster

lmao @RadvylfPrograms i just noticed you half shilling as well :P good show

seriously though i cant wait for LDW this is gonna be soooo crazaaay (talking about it like its a house party)

Seggan

^

only 3 quarters of a day left

thejonymyster

im so sad it starts like exactly when i start working :'D

emanresu A

19:27

@cairdcoinheringaahing Vyxal, 2 bytes

thejonymyster

woah, that output is pretty

emanresu A

I think we stole that from BQN?

user

19:44

@Bubbler Even better, write Rust in Vyxal/<your favorite esolang> and say "Why use Rust? Go down to the basics? Use Jelly/<your favorite esolang>"

Newly Featured Posts

37

Q: Addition on Elliptic Curves

Disclaimer: This does not do any justice on the rich topic of elliptic curves. It is simplified a lot. As elliptic curves recently got a lot of media attention in the context of encryption, I wanted to provide some small insight how "calculating" on an elliptic curve actually works. Introduction ...

16

Q: Knit me an ASCII-Sock

Introduction Long story short: a few days ago i accidentally started knitting a sock and the pretty logical structure of the plain stitches lead me to the idea: Why don't we just ASCII-knit a sock? Input The input is an even integer N in the range [2,30]. Output The output is a sock, obviously. S...

code-golf ascii-art

emanresu A

20:18

TIL Hertzbleed

forest

Neat.

Radvylf Programs

Huh, interesting

des54321

huh

thejonymyster

i hope nobody does that to me right now

des54321

i keep my processor's "Turbo Boost" off anyways because it makes my laptop overheat, but I doubt my personal laptop is a very high-value target for this sort of hack either

forest

20:21

@des54321 So do I, but for different reasons. But it's still fascinating.

thejonymyster

how do i know if it is on

or not on (i.e. off)

user

Honestly, if someone manages this, they almost deserve to get away with it :P

des54321

@thejonymyster check what task manager says is your cpu speed

forest

Could probably be mitigated fairly easily on Linux by having software frequency adjustments.

Radvylf Programs

Keep in mind this is a side-channel attack against very specific things, it's probably not ever going to be useful against ordinary laptops

thejonymyster

20:23

@des54321 base speed: 3.41 ghz?

des54321

> We know some of you don’t really like vulnerability logos, and we hear you. However, we really like our logo (and hope you do too!).

forest

@RadvylfPrograms I'd wager it could be done with a JIT-based side-channel attack in the browser.

Radvylf Programs

Yeah, but it seems much more limited than Spectre in its capabilities

des54321

@thejonymyster task manager should show something like this:

thats the right image

Radvylf Programs

I wouldn't imagine you could get much useful information from running it in someone's browser, even if it's exploitable in browsers which it might not be

des54321

20:25

if the green number is higher than the red number its probably on

forest

@RadvylfPrograms Spectre itself is a wide range of attack types.

thejonymyster

@des54321 ~~but theyre both brown~~ its fluctuating quite a lot but it doesnt seem steadily above it lol

ty

forest

So more limited in some ways, less in others. Also a different attack vector.

Radvylf Programs

Well yeah, but there were implementations of Spectre which could run in browsers. I don't think there are for this yet, and more effective side channel attacks isn't nearly as bad as a lot of what Spectre could do

des54321

@thejonymyster thats probably fine, on my computer if i let it turbo-boost the processor my clock speed jumps to about 3.5-4 GHz constantly, and my laptop quickly hits about 200 degrees fahrenheight

forest

20:28

The difference is that Spectre requires access to the same virtual memory region.

This, on the other hand, works cross-process. It's basically power side-channel, in software and over the network.

Tbh it doesn't look like a particularly powerful attack, but against servers it might be relevant.

Radvylf Programs

Spectre is cross-process, no?

forest

It's not.

The only way it can be sorta cross-process is if one process can cause another process to access its memory.

E.g. to attack the kernel you have to find "spectre gadgets", attacking the kernel from the inside out.

Radvylf Programs

Everything I'm reading is saying Spectre's cross-process, and can potentially even access kernel memory

forest

Look up if it's cross-VMA.

Because it's only cross-process if the other process has spectre gadgets, but that's not "really" cross-process because it's one process exploiting another.

And to access kernel memory it has to cause the kernel to attempt speculative memory access, e.g. using eBPF.

Radvylf Programs

@forest Yeah, that's mostly what I'm saying

forest

20:34

Ah

It just means that you can't attack an arbitrary process unless you can somehow interact with it in a specific way.

As opposed to, say, rowhammer which is truly cross-process because it attacks physical memory.

Wezl oOvOo

in Vyxal, Jun 10 at 13:52, by Wezl oOvOo

user: first response: Nice
wezl: first response: Expoitable :P

DLosc

21:29

@mathcat There is now :)

I didn't want to create one until there was interest.

Ginger

22:28

PSA: I will likely be less active here in the coming months, so if you ping me or something I might take a few days to get back to you.

The Sand Trap

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