The Nineteenth Byte

12:46 AM

Man code golf is extremely useful for making math exam study sheets. Instead of having to remember things like "how to tell if an adjacency matrix is symmetric" you can simply remember something like ¨=∩

att

uhh what

lyxal

And instead of having to remember the gcd algorithm for finding modular multiplicative inverse, I only need to remember the deleted 05ab1e answer to the relevant code golf challenge

@att ¨=∩ is Vyxal for "is invariant under transposition?"

att

instead of having to remember one algorithm I just need to remember a different algorithm

(:

a terse notation to express thoughts I guess

lyxal

@att 3 bytes is way shorter than having to write the whole definition

This is for a memory aid we're allowed to bring in btw

att

I feel like that's a bad example though

AT=A isn't exactly much more verbose

lyxal

12:52 AM

Maybe, but for me at least, writing it in golfing language equivalents is way more helpful

att

~~code golfer brain~~

if it works it works

personally I don't see where the advantage would be but then again the closest I got into golflangs was APL

would be kinda weird if I claimed to understand

OldSandboxPosts

Sandbox posts last active a week ago: write the "index by number" sequence, Zip two arrays

lyxal

I suppose it's because golfing languages are more intuitive to me than mathematics, as golfing languages are what I've spent the last 2 years of my life obsessing over :p

graffe

1:49 AM

@user I was thinking respectful tributes :)

emanresu A

4:00 AM

→ 15 messages moved to Fig

Neil

6:13 AM

@lyxal huh, why'd it get deleted?

tybocopperkettle

6:43 AM

I'm making a language in TypeScript at the moment and @emanresuA seems adamant that I'd be better off to not bother with floats and only have BigInts for arbitrary-precision integers. Before I go and do this, what are other people's thoughts on this?

Unrelated String

you should almost certainly also have floats but please do not use floats for integers

especially when ludicrously large integers can be legitimately useful for golf even outside of large inputs

emanresu A

6:55 AM

Thing is, JS floats and bigints go terribly together

mousetail

JS is just terrible for anything involving numbers

which is everything

lyxal

@Neil time restrictions

The challenge required all test cases under 60s

emanresu A

Should you be remembering an algorithm that's that slow?

tybocopperkettle

@emanresuA Yeah, I'm on the fence

lyxal

@emanresuA slow for really big inputs

O(n) kinda slow

Neil

7:11 AM

CMC: Draw a "flag" at half mast. Given inputs n, h and w, assume all are at least 3, draw n rows of |, then a box with size h by w using +, - and |, then another n rows of |. Box size can include or exclude the edges.

Charcoal, 12 bytes

emanresu A

TODO: Add boxes to vyxal's canvas

m90

@Neil Python 3, 76 bytes: lambda n,h,w:(f'|{"":{w}}|\n'*h).join(['+'+w*'-'+'+\n']*2).join(['|\n'*n]*2) -- Try it online!

lyxal

8:38 AM

→ 1 confused Web designer soul moved to The Nineteenth Bakery

Sandbox Posts

8:55 AM

0

A: Sandbox for Proposed Challenges

Re-Name all identifiers to a single letter code-golf Imagine a very simple language. It has just 2 syntax features: () indicates a block scope, and any word consisting only of lower case ASCII letters indicates a identifier. There are no keywords. In this language, the value of identifiers is not...

pxeger

10:04 AM

CMC: Easiest way to measure the mass (not weight) of a helium balloon

mousetail

Do you know the volume?

pxeger

You can measure the volume if you like, but that counts against your "ease score"

Sandbox Posts

0

A: Sandbox for Proposed Challenges

find overlap between 2 grids You have 2 grids with numbers inside, and you want to find the overlapping parts. For example The firdst grid 1 2 3 4 1 2 3 4 1 2 3 4 The second grid 2 3 4 1 2 3 4 2 9 8 6 4 This part is the overlapping part: 2 3 4 2 3 4 And when you combine, you sould get this: 1...

PyGamer0

10:41 AM

@pxeger turn you weighing scale upside-down and reset it to zero and put the helium balloon below it

oh wait will that work lol

pxeger

That doesn't include the mass of the rubber in the balloon

PyGamer0

:(

pxeger

And in fact that just measures the buoyancy force; I don't know enough about physics to say if that's easily related to mass

PyGamer0

buoyancy is related to weight ...

mousetail

@PyGamer0 It's just the weight of the air you are displacing right?

pxeger

10:48 AM

Oh I should add this rule: you may not pop or deflate the balloon

PyGamer0

@pxeger its the bouyant force, just use F=ma /s

mousetail

Is the balloon filled with 100% pure helium?

pxeger

I think that would make it too easy

Let's say it's mostly helium but also some unknown small proportion of air

emanresu A

@pxeger That can be measured from the packet

pxeger

The balloon is already inflated, you can't pop it, and there aren't any more balloons in the packet

mousetail

10:52 AM

Ok, then I'd do buoyancy yes. Weigh the balloon, subtract the density of air times the volume and you got the mass

emanresu A

@pxeger You have the packet though, from which you know what type of balloon it is

pxeger

There's too much batch-to-batch variance to rely on information about any other balloon

Stop side-stepping my problem!

@mousetail How do you measure the volume?

You can't really use the obvious method of water displacement because water sinks and helium floats

emanresu A

And? You can still shove it in

mousetail

Why can't you hold it underwater?

emanresu A

~~or locally invert gravity~~

mousetail

10:54 AM

I guess weight it underwater too since the pressue would decrease the volume

pxeger

I guess you could tie it to a heavy thing at the bottom of a tank of water, and then subtract the volume of the heavy thing and string

@mousetail That would also make it easier because the density of water is easier to find out accurately than air

emanresu A

My method: Get pxeger to do it.

PyGamer0

My method: ignore the problem

mousetail

My method: Guess 7 since it's always the correct answre

emanresu A

My other method: Get a volume integral wrong and come up with a negative mass. Then, open wormholes.

mousetail

11:40 AM

There is some quantum theory bases for negative mass. If you get negative volume though you are fucked

py3programmer

11:59 AM

I'd like some feedback for this question codegolf.meta.stackexchange.com/a/25107/110681 I wrote in sandbox

Ginger

12:17 PM

hello

It is me, Ginger

mousetail

@Ginger I disagree

Ginger

not this again

today, I am going to finally write up documentation for makina!

mousetail

Nice

lyxal

12:39 PM

@Ginger one could say you're makina effort to document it!

PyGamer0

12:51 PM

lol

graffe

anyone here remember basic probability? For a discrete random variable why does E((X - E(X))^2) = E(X^2) - E(X)^2 ?

thejonymyster

whats E(x)

mousetail

Expected value

Neil

@pxeger you weigh it inside a really big helium balloon

pxeger

That could work

Would it even need to be "really" big?

it just needs to fit the scales and balloon in

mousetail

1:01 PM

Just the baloon is enough right? You can tie it to the scales by a string

caird coinheringaahing

@graffe Expand, then apply linearity. Then, use the fact that E(E(X)^2) = E(X)^2 and E(XE(X)) = E(X)^2. I think, it's been a while since I saw the derivation

Wezl'

can u assume spherical balloon in vacuum :P

graffe

@cairdcoinheringaahing ah...E(XE(X)) = E(X)^2 Let me try this

pxeger

@Wezl' No!

mousetail

@Wezl' Would be super easy in a vaccuum

caird coinheringaahing

1:02 PM

@graffe Yeah, as E(X) is a constant

pxeger

@graffe E(X) is effectively a constant, so E(XE(X)) = E(Xk) = kE(X) = E(X)E(X)

graffe

ok got it. Thanks so much all

@Wezl' if it's full of concrete :)

pxeger

→ 22 messages moved to Off-Topic TNB

→ 1 message moved to Off-Topic TNB

New Posts

1:55 PM

2

Q: Solve a jigsaw puzzle

A jigsaw puzzle consists of (usually rectangular-ish) pieces. On each side of a piece, there is either an edge or a connector (a term I made up). A connector is either a tab sticking out (outie) or a slot facing inwards (innie). Two pieces can be joined if the outie tab can fit into the innie slo...

code-golf

user

2:07 PM

27

Q: Why does String creation using `newInstance()` method behave different when using `var` compared to using explicit type `String`?

I am learning about reflection in Java. By accident, I discovered the following, for me unexpected behavior. Both test as written below succeed. class NewInstanceUsingReflection { @Test void testClassNewInstance() throws NoSuchMethodException, InvocationTargetException, Insta...

java reflection string-pool

Somewhat interesting bug

DLosc

3:21 PM

@Neil Pip Classic -l, 32 bytes: YP'|RLaP['-s]XcWR^"+|"@:^1XbWR0y (flag size does not include the border)

I'm sure that can be golfed

Regenerate, 46 bytes (after replacing \n with literal newlines): ((\|\n){$~1})(\+-{$~3}\+\n)(\| {$~3}$2){$~2}$3$1

thejonymyster

3:52 PM

CMQ/LDQ: a truth machine can be done in two tokens with something like a dowhile print, assuming implicit input. what are some ways to have a 1 token truth machine without having it just as a "builtin"? my ideas so far are Dowhile where theres implicit output whenever the pointer reaches the end of the program (which wouldnt be useless as itd facilitate other infinite print loops), and Printtilfalsy, which i guess is a little sillier but the same idea maybe?

basically im just wondering if there are any other ways to approach this :-)

mathcat

I'm back

thejonymyster

welcome back mathcat, where ya been at?

mathcat

somewhere meeting relatives

I'm telling you, meeting relatives is the worst

(at least for me)

thejonymyster

cant be worse than meeting absolutes

mathcat

its worse

At best it went like:
Me: Hi
My brain: awkward awkward awkward awkward
Me: Die brain!

surprise, my brain didn't die

thejonymyster

4:00 PM

unloyal brain. doesnt it know the captain goes down with the ship

user

@mathcat It's not just you. i'm sure most people hate their relatives

mathcat

@thejonymyster I know right!

thejonymyster

^^

mathcat

anyways

@mods unfreeze plz

I see nobody stole my rep

Ha take that radvylf

I don't want your safe full of limbs

thejonymyster

4:15 PM

@thejonymyster This answer has an interesting approach :O

Aiden Chow

@Neil Knight 2.0, 96 bytes: ;=i+1=nP;=hP;=l@;=wP;W=i-iT=l+l,'|';O=s^l'\n';O=a++'+'*'-'=k+~2w'+';W<+=i+iT1hO++'|'*' 'k'|';OaOs, where \n is replaced by the literal newline

Neil

@pxeger I suppose it would work if you kept the outer balloon inflated while weighing the inner balloon

pxeger

Yeah that's what I was assuming

thejonymyster

4:35 PM

challenge idea: two languages, in language A, perform some task (open-ended-function), in language B, preform the same task pristinely(maybe ?), score being some function relating to the ratio of sizes of these programs, goal being to maximize

so find a task that Lang A is really good at but Lang B is really bad at

issues i can think of: "longer is better" challenges are hard, easy to pick a golfing lang and a tarpit also

oh wait i know

you have to do one the other way as well, short in Lang B, long in Lang A

Deadcode

@DLosc Thank you.

thejonymyster

to "prove" that both languages operate at roughly the same level or something :P

Deadcode

It's been so hot here for the past few weeks I've been barely able to think. (I don't have air conditioning.)

@thejonymyster What if they're the same language, except for one thing being added (or removed)?

thejonymyster

like a flag?

or a version difference? i mean sure yeah thatd be different enough

i guess its still an issue of "what if i can write a way longer pristine program in this same language anyway" idk

Deadcode

@thejonymyster There's a particular problem that's 771 bytes in ECMAScript regex, but 128 bytes in ECMAScript + (?*)

thejonymyster

4:44 PM

right thatd be fine, my other idea was that youd have to also write a program that was short in lang b but long in lang a

brainstorming still idk

Deadcode

@thejonymyster It's a neat idea, but what would prevent people from just picking lang A to be something that everything is really long in?

thejonymyster

having to do it both ways

Deadcode

How about, something like, requiring that for some other function, the ratio is much closer to 1?

or that, yes

thejonymyster

task 1: short in A, long in B
task 2: short in B, long in A

the ratio being close to 1 is interesting but much less restrictive

Deadcode

well, that would rule out lang B being the same as lang A but with one function added

thejonymyster

4:55 PM

tragically u_u or fortunately? neutrally

mathcat

@thejonymyster interesting

thejonymyster

im worried it wouldnt even rule out just using Lang A twice though, since what if you can just write a pristine program thats longer than the regular program :?

Deadcode

it'd still allow letting lang A and lang B both be based on lang C, but with a different function removed in each

@thejonymyster well it'd have to be golfed in good faith.

which could be difficult to judge of course.

thejonymyster

yeah long program restrictions is hard still

sorry im like language words bad right now LOL

language processing fail :'-)

Deadcode

@thejonymyster What do you mean by "pristine"?

thejonymyster

5:11 PM

umm a pristine program is like, if any contiguous substring of the program is removed it must error, though i think thats not what i want

idea being that you cant just pad out your program for length

i think "irreducible" is what im looking for, but i know that has its own issues since its possible to make arbitrarily long irreducible programs in some languages kind of?

DLosc

@user Don't be so sure. Anecdotally, I and several people I know are counterexamples. I certainly have some relatives I'm guarded around, but I don't hate them. And some of my relatives are on my top 5 favorite people in the world list.

Wezl'

Anyone know what some good resources are for an introduction to code golf? besides just a link to cgcc :P

(they have some coding knowledge like scratch and python, and they seem interested in other types of competitive programming including speed coding)

caird coinheringaahing

@Wezl' Honestly, just send them here :P

Radvylf Programs

Yeah I mean, a large, active, and friendly community where you can also see other people's answers, and get an introduction to a variety of practical languages, esolangs, and golflangs in a golfing context isn't that bad of an introduction to code golf IMO

caird coinheringaahing

Or, if they're someone you're friends with, I'd suggest finding challenges and doing those together, then looking at the "best" posted answer in that language

Wezl'

5:22 PM

also mostly I want them to learn about it, because I'm not sure they're actually interested in participating rather than just appreciating that it exists

oh that sounds fun

DLosc

@Wezl' I vaguely remember reading a blog post years ago that went through a step-by-step process of golfing 99 Bottles of Beer (in Python maybe? or Perl? or both?). No idea how to find it now, though. Google is mostly coming up with solutions on code golf sites.

Wezl'

also I showed them codingame as an example of something timed

user

6:21 PM

@DLosc note to self: don’t assume everyone is as unfriendly as you :p

mathcat

lol I may be a bit biased too

user

Tbh i don’t hate most of my relatives, just the ones who are like “it’s your favorite uncle! I held you for two seconds when you were a newborn. What?! You don’t remember me?” and the ones who try to pry any information out of you they can

mathcat

@mathcat The last relative I met was my cousin who had a very big ego

@user so true

Wezl'

yes

user

Hate is a strong word there too

I wouldn’t punch them but i wouldn’t be too sad if someone else did

mathcat

6:25 PM

The thing is, I don't hate my relatives, I just don't like meeting them.

Someone please tell me there's a difference

Steffan

Most of mine live on the other side of the world so I don't see them much

user

There is

I bet they hate family events too

mathcat

@Steffan same

user

@Steffan me too, but my parents make me call them all the time

Wezl'

My relatives aren't bad, but I don't like when they give me unsolicited advice for what to do when my life ends up being exactly like theirs and I face the same problems etc

user

6:27 PM

It’s so embarrassing being a grown adult and calling your grandma on your birthday because your mom told you to

@Wezl' lmao yeah

Steffan

They came over here where I live once, but they don't like to so they never did again

@user Well yeah they call like every week lol

Seggan

@Steffan hehe, and i thought mine lived far away...

user

“What’s that? You have a hard time running a mile? Drink an ounce of my homemade remedy everyday and you’ll be a muscleman in no time “

Wezl'

"little wezl when you start liking the opposite sex youll care more about [something]"

Steffan

Okay, it's not quite the other side of the world, but across the ocean

user

6:29 PM

@Wezl' oof

User it’s no wonder you don’t have a girlfriend yet if you’re so thin (I’m not). It’s time to start thinking about that seriously now (this in high school)

I wish you could choose your relatives

mathcat

My relatives are basically all non-vegetarians, so I had to endure each one of them saying "A chicken a day keeps the boogeyman away" and that sort of stuff.

Wait what

not exactly but yes

Chicken? Bogeyman?

heheheh veg gang

6:33 PM

id be vegan if it weren’t for ice cream and bacon

And apparently because the bogeyman gets vegetarians

Wezl'

one summer I made exceptions so I didn't have to talk about it to those same relatives

lol

user

That sucks

mathcat

uff

Wezl'

@user that's just because vegetarians are immune to hazards made of flesh and blood, so the bogeyman is just proportionally more dangerous :P

at least in the case where the bogeyman is some ethereal ghost thing

or is made of vegetables :P

user

@Wezl' maybe it’s iron man :p

mathcat

6:39 PM

Steffan

What

That's a vegetarian boogeyman?

Wezl'

this is what ai is actually for :P

Steffan

I guess he is what he eats

Wezl'

artificial imagination

Radvylf Programs

#1 is the fastest. It chases you down at incredible speeds, pinning you down between its various legs. It eats you quickly if you are a fellow vegetarian.
#2 is a more careful killer. It hides in enclosed spaces near where humans sleep. They wake up in its presence, but cannot move.
#3 uses his victims as test subjects for horrific experiments. He doesn't really like how vegetarians taste, but they're better than microwave dinners.
#4 hides in dark, abandoned rooms. Its disfigured body is optimized for attics and old hospitals. It idly snacks on vegetarian spiders while it waits for prey. I…

7

Wezl'

6:45 PM

vegetarian spiders in dark abandoned rooms eat mold ig ?

Seggan

The Sand Trap

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

3

Wezl'

I mean we're not interrupting anything but that makes sense for a possibility when some other (on-topic) conversation starts

Radvylf Programs

Plus I doubt very many of us will be brave enough to continue talking. The vegetarian boogeyman have probably had time to approach us.

Wezl'

I don't see anyt-

Steffan

I tried asking craiyon.com about the veg boogeyman and it was really spooky lol

Idk what mathcat used

pxeger

6:55 PM

> It eats you quickly if you are a fellow vegetarian.

Is there a name for someone who eats meat and vegetables, but only meat of vegetarians?

Radvylf Programs

Yeah, those are vegetarians. If you don't eat vegetarians, you're a vegan.

mathcat

7:14 PM

@Steffan I used deepai

pxeger

A second-order vegetarian?

3

emanresu A

@RadvylfPrograms But by that, everyone is a vegetarian, since animals are vegetarians by that

Radvylf Programs

Oh. That's actually a pretty good point. Frick.

Okay the recursion limit for vegetarianism is 2.

Wezl'

kay just most now

user

@RadvylfPrograms I don't like this solution. We could just differentiate between different orders of vegetarians instead

Wezl'

7:21 PM

but is it also invalid if it eats a plant that eats an animal that eats an animal?

mathcat

*That Vegan Teacher joins the chat*

user

Wait this is TNB

Why are we having this conversation here

Wezl'

T v T is fake smile, real crying emoticon :P

Radvylf Programs

@Wezl' Plants that eat animals are considered vegetarian animals which do not eat vegetarians

user

This makes so little sense it's practically a branch of science now :P

Radvylf Programs

7:23 PM

It's called ecology silly

Wezl'

@user this discussion is important to our social emotional health which impacts our ability as code golfers :P

@RadvylfPrograms mixed with a bit of ... what do you call the branch of science that the bogeyman's in :?

emanresu A

mucology

thejonymyster

@user code golf challenge: given a list of people and their dietary choices (and the dietary choices of their dietary choices) determine what order vegetarian they are

user

Heh, might even be a duplicate

DLosc

8:56 PM

@mathcat Oh yeah, that's definitely two different things.

@Wezl' So relatable. They usually mean well, but my life != your life.

@user So that's what I'm doing wrong! =P

Unrelated String

9:26 PM

@user i can barely stand interacting with my mother to begin with, her half-siblings are right out :P

user

9:38 PM

:(

Radvylf Programs

Tbh I don't really have all that many relatives that I actually know anything about. All of them on my mom's side are in California and we have zero contact (aside from them sending us a single package of store bought salami each year. no clue.). On my dad's side they all live in East Texas and are apparently pretty racist.

I have no clue what's up with the salami. And for some reason my parents still act like it's something special and rare, so they'll never let us eat any, and every year without fail more than half of it goes moldy

Even though I've literally found the same brand at Walmart

caird coinheringaahing

> pretty racist East Texans

I mean, I don't want to stereotype :P

Wezl'

@RadvylfPrograms i n t e r e s t i n g tradition

Seggan

10:07 PM

in Fig, 1 min ago, by Steffan

yeah, I know, you write a piece of code, it works perfectly as far as you can tell, and every single person who tries it except you finds 100s of bugs in it

Radvylf Programs

Happens a ton with golfing languages

Every single operator has its own potential to harbor a dozen edge cases

Steffan

happens with most any code :P

Radvylf Programs

Well yeah but, especially with golfing languages

Debugging each one of Ash's operators took twice as long as actually writing them, and I still ran into weird edge cases all. the. time.

caird coinheringaahing

@RadvylfPrograms Jelly isn't susceptible to this problem *hides literally half the quicks*

Radvylf Programs

I've never used unit tests before, but once I start on my next golfing language, I'm going to learn

I'm also going to use Rust, which'll help

caird coinheringaahing

10:09 PM

¦, ⁺, ', ƙ can all die

Seggan

@RadvylfPrograms how

Radvylf Programs

Because that's like, Rust's whole thing

Being hard to write errorful code in :p

Seggan

i thought it was memory safety

that was rusts specialty

Radvylf Programs

That's part of it, but the safety goes way beyond memory safety

The way it's designed rules out whole classes of errors, and its warnings are great

Seggan

examples?

i dont see how a design can rule out bugs

maybe except static typing

Radvylf Programs

10:13 PM

Aside from static typing, you've got Options instead of null, Rust's enums in general, mut making you be careful about what you mutate, match being able to alert you to missing cases, and possibly most importantly, Result and being forced to unwrap or otherwise handle things that can error

You also look at your code a lot more in the hours it takes to get it to compile lol

emanresu A

10:24 PM

@RadvylfPrograms Vyxal isn't susceptible to this because we did all of that already

Radvylf Programs

Also another reason golfing languages tend to harbor bugs is that often you're not only tolerating edge cases, but intentionally exploiting them as ways to save bytes, so you're adding extra functionality to what's already the most bug-prone part of most things

caird coinheringaahing

@RadvylfPrograms If I can't multiply characters by numbers to create types that shouldn't exist, what's the point of using that language?

DLosc

@cairdcoinheringaahing Funny you should mention that, I was just thinking about how to handle character & number arithmetic in a golflang...

Unrelated String

fr

@DLosc addition and subtraction on code points don't seem like a bad idea, but that raises the question of how you could have multiplication and even division that's both sensible and useful

Radvylf Programs

That seems really niche

Unrelated String

10:32 PM

@cairdcoinheringaahing wait what are the weird edge cases on ⁺

Radvylf Programs

Having characters at all in a golflang seems like a really bad idea honestly IMO

caird coinheringaahing

@UnrelatedString That it doesn't technically group the repeated atoms together

Radvylf Programs

Strings as their own data type just make more sense for overloading purposes

caird coinheringaahing

Like +H⁺ != +HH$

Unrelated String

i feel like strings should be treated identical to lists in as many circumstances as possible
and then you can have dedicated string overloads only where the alternative would be using numeric builtins on characters

DLosc

10:35 PM

@UnrelatedString Yeah. I also like the idea of being able to multiply a character by 0 or 1 and get a falsey value or the same character, respectively.

Unrelated String

@DLosc oh yeah that's super useful

@cairdcoinheringaahing i feel like that's just a problem with the description of "duplicates the previous link" kind of suggesting that it's some kind of 2¡ alias

Radvylf Programs

@UnrelatedString There are plenty of string operations more useful than array operations on strings though

It feels too absolute to say "only overload array operations when they are literally meaningless on a string"

caird coinheringaahing

@UnrelatedString Yeah, either behaviour would be fine

It's just weird when combined with link combinators

Unrelated String

i can't think of many cases but i feel like the more general one we have is as useful as not

yeahh

DLosc

@cairdcoinheringaahing :P

caird coinheringaahing

10:38 PM

That (almost) works in my fork :P

DLosc

Nice--almost?

Unrelated String

@RadvylfPrograms almost any string operation can be a general array operation; string overloads are just a way to make it easier to use some of them

caird coinheringaahing

I've overloaded ‘ and ’ (increment/decrement) to work with characters, but haven't for general addition

DLosc

Ah

Unrelated String

xd

caird coinheringaahing

10:39 PM

So ”a‘ works, but 1+”a doesn't :P

The Sand Trap

Transcript for