The Nineteenth Byte

Erik the Outgolfer

6:00 PM

well then it would still be 9 chars :p

DJMcMayhem

because ({({}|<>|| All of the monads are uniquely decodable

@EriktheOutgolfer Better than 12 :P

HyperNeutrino

so the goal here isn't to infer things (like (()[)} -> {(()[])}) but just to transliterate to a more efficiently encoded thing? :P

Erik the Outgolfer

and then there's the solution with 3 chars

DJMcMayhem

I guess? TBH, I'm not sure what the goal is

Erik the Outgolfer

(    -> (
)    -> )
-(   -> [
-)   -> ]
--(  -> {
--)  -> }
---( -> <
---) -> >

or even 2 chars

if the goal is to get the least chars possible

DJMcMayhem

6:02 PM

1's and 0's?

Erik the Outgolfer

like | -| --| ---| ----| -----| ------| -------| -> ( ) [ ] { } < >

and you can even do it with 1 char, like the Unary language

HyperNeutrino

000 → (
001 → [
010 → {
011 → <
100 → )
101 → ]
110 → }
111 → >

DJMcMayhem

@HyperNeutrino OK, but that brings a problem: How would you encode... idk for example (((?

Because you can't save 9 bits to your hard drive.

HyperNeutrino

true

Erik the Outgolfer

I don't think that's a problem

padding will solve it

HyperNeutrino

6:05 PM

then you'd need to pad, but all bit configurations are already taken

anyway gtg o/

DJMcMayhem

@EriktheOutgolfer But what would you pad it with?

Erik the Outgolfer

@DJMcMayhem trailing opening brackets

Riker

see ya @HyperNeutrino

DJMcMayhem

Hmmm

I guess that's fair

We don't necessarily need to correctly encode invalid code

Erik the Outgolfer

and if you are left with a chunk of less than 3 bits at the end, just throw it away

DJMcMayhem

6:07 PM

Or you could just use base 255 and enumerate all valid catalan numbers

(valid brain-flak programs)

caird coinheringaahing

@Riker I'm beating you in hats :P

DJMcMayhem

Enumerating brain-flak sounds hard

Christopher 2EZ 4RTZ

@DJMcMayhem wp. I hate you now :P

And now I will get no up votes as usual lol

DJMcMayhem

Hehe

Riker

@cairdcoinheringaahing not network though?

ah, yep network

I'm still working on a challenge to post on ppcg

HyperNeutrino

6:15 PM

oh god the hats are all over the place

i hate hats?

NOO it still displays the hats. i'm mad

caird coinheringaahing

@HyperNeutrino Why do you hate hats?

Mr. Xcoder

@HyperNeutrino You really hate hats that much? :P <----

Erik the Outgolfer

@HyperNeutrino simple button click ;)

HyperNeutrino

I don't :P It's just that the hats are so intrusive because none of your profile pictures are loading so they're at max size :P

caird coinheringaahing

I love Winter Bash :P It's so fun :D

Mr. Xcoder

6:17 PM

@cairdcoinheringaahing How the hell did you overtake me that badly during a single day?!?! I must do something about that

caird coinheringaahing

Rep capping helps :P

Mr. Xcoder

I have the repcap hat too :/

Oh I forgot to post my challenges for Hero of time

caird coinheringaahing

I got Just Jesting, I'll Handle It, Taco Tuesday and Rep Cap today :P

Mr. Xcoder

I need I'll handle it :/

And... I should go get that electorate badge

caird coinheringaahing

Using all 40 votes in one day stops you from doing first post and late answer reviews, so I'm doing my voting at about 23:00 :P

Mr. Xcoder

6:22 PM

Hehe, currently beats Pyth. \o/

/facepalm

New Main Posts

1

Q: Parse the Parcel

Thanks to your help in the Mark My Mail challenge, PPCG-Post has successfully stamped all of its parcels with the generated barcodes! Now, it's time to decode them. In this challenge your program will, given a barcode generated from the Mark My Mail challenge, decode it and return the encoded i...

New Main Posts

6:42 PM

0

Q: Google's Hopping Bunny

On December 4, 2017, the Google Doodle was a graphical programming game featuring a bunny. The later levels were nicely non-trivial and they seemed like a great candidate for an atomic-golf challenge. Details Game There are four available moves: hop forward, turn left, turn right, and loop. E...

code-challenge atomic-code-golf

El'endia Starman

^ There you go, @user202729 @EriktheOutgolfer.

Erik the Outgolfer

saw that already :p

Riker

7:13 PM

@EriktheOutgolfer you could use #coding:L1 instead though

then with 3 lambdas it's shorter to do that

New Main Posts

1

Q: Communistic Substring Normalization

If a string T of length K appears K or more times in a string S, then it is potentially communistic. For example, 10 in 10/10 is potentially communistic, for it appears 2 times and is of length 2. Note that these substrings cannot overlap. A communistic transformation is one that takes this st...

code-golf string

Anonymous

7:29 PM

@Riker ISO-8859-1 doesn't contain the Greek lambda char

New Main Posts

0

Q: What is the simplest reversible circuit that computes conjugacy of transpositions

Let T5 be the set of all transpositions on the set {1,2,3,4,5}. Let * be the operation on T5 defined by x*y=xyx^(-1) (here concatenation denotes the group operation). In other words, the underlying set of T5 consists of all 10 pairs (a,b) of distinct numbers from {1,2,3,4,5} and where (a,b)=(b,a)...

math permutations logic-gates

Riker

@Mego oh, whoops

TIL though

Anonymous

8859-7 and cp1253 are the only ASCII-compatible code pages that I'm aware of that contain Greek letters. cp875 is close, but it's EBCDIC, so the ASCII ordinals don't match up.

Neil

yay I have hats at last

FlipTack

7:47 PM

my rep is at a nice round 8,300

it's probably satsifying me far too much

Neil

8300 isn't nice because 8 isn't a square :P

FlipTack

someone give me a 700 rep bounty and then it will be :)

DJMcMayhem

@Neil It is a cube though

FlipTack

8:10 PM

I'd say it's nice as the 3 and the 8 could stand for cuberoot(8) which is 2, represented by the 2 zeroes

Leaky Nun

illuminati confirmed

Neil

@DJMcMayhem that doesn't make it a pleasing number though

Anonymous

FlipTack numbers: numbers of the form abx, where x is a number repeated a number of times equal to the bth root of a (a must be a perfect bth number (square, cube, etc.)).

Anonymous

8:27 PM

Oh wait that's exactly the definition of a pleasing number

Anonymous

Well, close

Anonymous

I'll make the challenge :P

AdmBorkBork

npm is the bane of my existence

FlipTack

@Mego needs to be on OEIS :P

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

I originally asked this question, but it was closed under "unclear what you are asking." TITLE: What is the simplest reversible circuit that computes conjugacy of transpositions? Reversible computation refers to computation in which little or no information is deleted. Reversible computation a...

Riker

8:43 PM

MO is confusing

also, that's the first MO HNQ I've seen

mınxomaτ

@El'endiaStarman Word embeddings are semantic vectors. The numbers represent the meaning in context, which allows you to compare e.g. different sets of association. A thorough introduction is here: blog.conceptnet.io/2016/05/25/…

El'endia Starman

@Riker You must be new to MO. I have a math degree and could probably understand about 5% of the questions/answers.

Riker

@El'endiaStarman I have no maths degree and my limit right now is my calculus homework :p

El'endia Starman

@Riker The concepts of calculus are really cool. The homework, less so.

Riker

@El'endiaStarman I'm just starting integration now so it's not that bad

Wheat Wizard

8:48 PM

I really did not like calculus

I'm very glad I am done with it

Riker

you can't deny precalc is worse

precalc is when they decide you haven't done enough long multiplication

and give you more but this time you get 'x's

El'endia Starman

@Riker Let me know when you get to differential equations so I can give you a shoulder to cry on.

Riker

@El'endiaStarman I've covered most derivative stuff so far, not sure what those are

did implicit diff already

Wheat Wizard

@El'endiaStarman Differential equations was my favorite part of calculus. But that's not saying much.

El'endia Starman

@Riker A differential equation typically refers to an equation where (the derivative of some variable) = (an expression with that variable). They're typically very messy to solve symbolically.

Riker

8:52 PM

both explanations make 1/2 sense so I'm pretty certain what you mean

@El'endiaStarman well I thought I couldn't get messier than the antiderivative log rule thingy

Wheat Wizard

For example f(x)=f'(x) is a really simple differential equation.

El'endia Starman

For example, d/dt T = -k * (T - T_environment) is one way to formulate Newton's Law of Cooling. In English, the temperature of something changes at a rate proportional to the difference between it and its surroundings.

DJMcMayhem

@Christopher2EZ4RTZ Bug is fixed. Everything works now: Try it online!

Riker

@WheatWizard not that one

hold on 1 sec

Mr. Xcoder

@StevenH. New tag proposal: steven-beat-me-to-it :-) - Officially, my favourite things on PPCG are Pyth duels. So glad some other people are still interested about It :D

Riker

8:55 PM

this one

not sure what its called

Taylor Scott

Hey y'all, I've got a question regarding Excel and Excel VBA - Do you think that shortening Cell addresses to single letter names like this is valid?

El'endia Starman

@Riker Not sure either, but I'd just call it the reverse of the power rule. With a special case.

Wheat Wizard

@Riker I would call it the power rule.

Anonymous

@El'endiaStarman Been there, done that :P

Riker

@WheatWizard is there really no simpler way for the reverse of the power rule? huh

Wheat Wizard

8:57 PM

Well its pretty simple actually. Almost all of the time you are going to be using the top half

the bottom half is a special case because the top would require you to divide by zero

Riker

@WheatWizard I don't see how that follows from the power rule though

(the bottom half)

Wheat Wizard

The bottom half doesn't follow from the power rule

its unrelated

Riker

where does that come from then?

Pavel

A train fell onto the highway near where I live just now.

komonews.com/news/local/…

Wheat Wizard

the fact that the derivative of log is 1/x

Anonymous

9:00 PM

Simpler example of a diff eq: m*((d^2 x)/dt^2) = -k*x (simple harmonic motion)

Riker

@Pavel that's not good

Anonymous

@WheatWizard For real x :P

Riker

@WheatWizard TIL

Wheat Wizard

@Mego for positive real x

Riker

guess that makes sense though

El'endia Starman

9:01 PM

Look at it this way. When you differentiate x^n and look at the exponents, they follow this pattern: 3 -> 2, 2 -> 1, 1 -> 0, 0 -> 0, 0.5 -> -0.5, -1 -> -2, -2 -> -3, etc. There's no integer n for which the derivative of x^n is some multiple of x^(-1). That's where the special case of d/dx ln(x) = 1/x = x^(-1) comes in.

Wheat Wizard

@Riker I don't think it's a very good idea to put the two things together, if I were you I'd try to think of them separately. If reversing the power rule fails to yeild an answer then try the second one.

Mr. Xcoder

I also have a question regarding integration (I am very, very, very new to calculus since we study this in maths in 3 years from now): If a function is not continuous between points a and b, can one apply a definite integral from a to b with that function?

Yes

@Mr.Xcoder yes

Ugh really? Thanks

9:03 PM

A function can be integrated if it is "integrable", all continuous functions are integrable, but not all integrable functions are continuous

El'endia Starman

You can even do it if the function has a hole in it where a value is undefined so long as filling in that hole with a single value will make the function continuous (another way of saying that the left- and right-sided limits exist and are equal).

Mr. Xcoder

Good to know

Wheat Wizard

an example would be:

Which is discontinuous at x=0, but can still be integrated.

Anonymous

@WheatWizard Well, sort of. The derivative of a function doesn't have to be restricted to the function's domain, but it's not terribly useful to talk about the derivative of a function outside of the function's domain. Also if we want to get really pedantic, d/dx log_b(x) = 1/(x ln(b))

Wheat Wizard

Fair enough.

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