The Nineteenth Byte

@EriktheOutgolfer I agree. However, it's mostly feature-frozen right now while I'm working on refactoring and porting to C++. The port to C++ will be both for an interpreter in C++, and also a way to compile to C++ from Actually.

Mr. Xcoder

2:06 PM

@SimplyBeautifulArt Me too. I didn't start studying it yet, because my professors and colleagues are quite slow.

HyperNeutrino

I'm really fortunate I got to start learning interesting math earlier on because school here offers no interesting stuff (at least for me) lol

Simply Beautiful Art

@Mr.Xcoder I studied it on my own, which I think to be the best option if one seriously wants to learn some topic to a decently advanced level.

Erik the Outgolfer

@SimplyBeautifulArt in greece we do prime factorization starting from elementary school class D (i.e. 4th grade)

Anonymous

@EriktheOutgolfer Seriously though, if there are any bugs I'm not aware of, please open issues on GitHub. All 5 issues currently open are enhancements. I don't know of any bugs currently in the Python interpreter.

Simply Beautiful Art

@HyperNeutrino :( That's how they all are.

Mr. Xcoder

2:07 PM

@SimplyBeautifulArt I don't really want to learn very advanced mathematics. I am on the Physics side of the wall :)

Simply Beautiful Art

@EriktheOutgolfer x.x In my 4th grade class, I remember the beginning of learning how to multiply.

@Mr.Xcoder Well then go study that :)

Mr. Xcoder

@SimplyBeautifulArt I do study that for ~3 years now :-)

Simply Beautiful Art

That's great! Best of luck to your physics.

user202729

@HyperNeutrino Why are you implementing BFS that way??!??! Very inefficient... (I know this is not fastest code, but...) || Where do you find learning materials? I really want to know...

Mr. Xcoder

@SimplyBeautifulArt Thanks! Good luck with maths and moderation!

Erik the Outgolfer

2:09 PM

@SimplyBeautifulArt that was in second grade (class B)

Simply Beautiful Art

@Mr.Xcoder :-) To be honest, I'd be very satisfied with whoever wins the election, out of those that are likely to be elected.

HyperNeutrino

@user202729 I never learned how to do BFS well so that's just what I'm guessing :P || A university professor at UW offers time to teach me and a couple of my friends extra math outside of school

Anonymous

@SimplyBeautifulArt I just realized why I recognized your name! Good luck in the election!

Simply Beautiful Art

Lol, thanks.

Anyways, cya everyone!

Erik the Outgolfer

in fourth grade we do stuff such as $\frac ab\times\frac ba=1$

HyperNeutrino

2:11 PM

o/

Erik the Outgolfer

bye

Mr. Xcoder

@EriktheOutgolfer Same here (fractions in grade 3-4)

HyperNeutrino

@EriktheOutgolfer Really? We started fractions in like grade 5/6 if I remember correctly :(

Or maybe we started in grade 4 but kept doing the same things over and over so I can't remember when we started it.

Erik the Outgolfer

...started? lol greek education system is very different (but horrible overall)

for me that was 3rd grade

6th grade was number larger than one billion, gcd, etc. 5th grade had lcm

Mr. Xcoder

Yeah 3rd grade here too

5th grade lcm and gcd

Anonymous

2:14 PM

I think LCM and GCD were either 4th or 5th grade for me

Erik the Outgolfer

btw 9th grade was lcm and gcd of polynomials

Mr. Xcoder

I am in the 8th rn :-(

Anonymous

Polynomial algebra was 10th for me

user202729

@HyperNeutrino And what's with int[length * ~-length * ~-~-length / 6] and combine(nodes, old, (x, y) -> x ^ y)? Are you going to obfuscate the code?

Erik the Outgolfer

also solving systems was 9th grade too

HyperNeutrino

2:16 PM

Polynomial stuff was grade 10 though I'm not sure whether or not they started it in 9 because I didn't do grade 9 math.

Fatalize

@EriktheOutgolfer "6th grade was number larger than one billion"… wait what?

what is there to study on this?

Anonymous

Linear systems was 10th. 9th was geometry and proofs for me.

HyperNeutrino

@user202729 Hm? What about it?

Yeah linear systems for grade 10 and since it was the pre-AP class we briefly did matrix stuff

Mr. Xcoder

We study both geometry and algebra from grade 6

Erik the Outgolfer

@Fatalize like, handling them (mainly +, -)

user202729

2:16 PM

Should it be length * (length - 1) * (length - 2) and (x, y) -> x != y?

Fatalize

@EriktheOutgolfer I don't get it. That's the same as for smaller numbers

HyperNeutrino

@user202729 I personally think ^ is faster than != marginally though I'm not sure. And no, I apparently hate brackets :P

Erik the Outgolfer

also in 9th grade I started testing equality of triangles and proofs in geometry

@Fatalize yeah didn't make sense

at least to me

Mr. Xcoder

WHAT? In the 9th grade triangles and proofs in geometry? :ø We do those in grade 7.

HyperNeutrino

I can't even remember how grades 5 - 8 went for me because I was not in a regular class so my math education was entirely outside of school lol.

Anonymous

2:19 PM

My high school math was: 9th (geometry, proofs), 10th (linear algebra, polynomial algebra), 11th (precalculus, limits, growth rates of functions), 12th (differential and integral calculus, sequences, series)

Fatalize

searches on google what's the link between grades and age

HyperNeutrino

@Fatalize age - 5 = grade

Erik the Outgolfer

there's a shift from K to 1st grade (from kindergarten to elementary), 6th to 7th grade (elementary to middle) and 9th to 10th (middle to high)

HyperNeutrino

a bit different for people with birthdays during the school year but I forget the offset range

Anonymous

@Fatalize 9th grade is usually 13-15 in the US

HyperNeutrino

2:20 PM

All I needed to do for grade 7-8 math class (which was in my homeroom) was take the pre-test, ace it, and not do anything that unit :P In grade 5-6 it wasn't much different

Fatalize

13-15 is two years??

Erik the Outgolfer

3 years

Anonymous

@Fatalize No, I mean the common ages. 9th grade is one year, and people in 9th grade are typically 13-15 years old

Fatalize

I don't get it

how are they not all the same age, besides exceptions?

Erik the Outgolfer

I think he means what age range 9th graders usually are

Anonymous

2:21 PM

@Fatalize It depends on when their birthday is in relation to the start of the school year, being held back or advanced forward grades, when they started school, etc.

HyperNeutrino

People born in December might be 13 for the beginning of Grade 9. People born in January might be 15 for the last half of Grade 9. I think.

Erik the Outgolfer

January-June: 14-15, September-December: 13-14

Anonymous

Also every school district (in Texas, at least) makes their own rules regarding when students start school, so transferring between school districts can lead to some outliers

Fatalize

Huh

Anonymous

And homeschooling causes even more headaches

Erik the Outgolfer

2:23 PM

@Mego horrible

Fatalize

Here, it's based on your year of birth, we don't care what month you were born in

Anonymous

@EriktheOutgolfer Freedom™ (some restrictions apply, see store for details)

Erik the Outgolfer

that's the usual case

Fatalize

@Mego Too edgy for graph theory

Erik the Outgolfer

also greece has "necessary education", i.e. grades you are required by law to complete grades K-10 unless you get stuck in any of 7-10 for many years

Mr. Xcoder

2:25 PM

Yeah, 10 grades are mandatory here too

(although we have 13)

Erik the Outgolfer

like, 13 grades?

that's unusual

HyperNeutrino

I'm not exactly sure about Canada's requirements for which grades you must take. I think it's just K-8 but the entirety of high school is necessary if you want a decent career.

Anonymous

In the school district that I attended for most of my grade school education, the requirement is that kindergarten students must be 5 years old on September 1 of the school year in question, and that 1st grade students must be 6 years old on September 1.

HyperNeutrino

We also have an optional 5th year of high school.

Erik the Outgolfer

@HyperNeutrino like, K-14?

HyperNeutrino

2:26 PM

No it would be K-13.

Grade 9-12 is regular high school.

Huh. Apparently lean fish isn't a valid advancement from butterfly.

Fatalize

@Mego Kindergarten counts as a mandatory school year?

Erik the Outgolfer

isn't grade 7-9 middle school?

Anonymous

@Fatalize Nope, but there are rules for enrolling

Mr. Xcoder

@EriktheOutgolfer We used to have 12, but our odd politicians moved the last year from kindergarten to school instead... We now have "Grade 0", which I unfortunately didn't take.

Erik the Outgolfer

> last year in kindergarten

wat

ok either our education system is very different or something not entirely normal is going on

Anonymous

2:29 PM

In Texas, the law is that kids are required to attend school until 16, no matter what. They are required to attend school until 18, unless they already have a high school diploma or are in some sort of alternate education program (GED, high school/college hybrid studies, etc.).

HyperNeutrino

In Canada we have JK/SK is kindergarten, 1 - 6 is elementary, 7 - 8 is middle, 9 - 12 is high, 13 is optional 5th year high school.

Anonymous

@EriktheOutgolfer Some places consider any schooling prior to grade 1 to be kindergarten. In the US, we usually refer to that as pre-school or pre-kindergarten (or both).

user202729

@HyperNeutrino How can your isomorphic function be correct?

HyperNeutrino

It brute-forces all re-labellings of the nodes

user202729

But there are only n! relabel. The algorithm looks like it considers n!² different matrices.

E.g.,
Matrix 1
1 0
0 1

Matrix 2
0 1
1 0

Erik the Outgolfer

2:31 PM

@Mego in greece 4-6yo is kindergarten

HyperNeutrino

Well yeah, it's really inefficient. It shuffles the adjacency matrix in both dimensions.

user202729

The first one consists of 2 loops on each vertices, the second one has a double-edge connect two vertices.

HyperNeutrino

oh...

huh...

user202729

Not to mention that it only transpose once. It should be equal(transpose(P), b.l).

HyperNeutrino

Huh. Wait how do I rewrite my isomorphic check then...?

user202729

2:34 PM

I will try to rewrite it.

HyperNeutrino

I could turn it into a list of edges and permute the edge labels instead. That's what I do when I represent the graphs as edge lists.

@user202729 ok thanks

I noticed that even though I prefer Python by a lot over Java, I'm more likely to write working code on my first try in Java than Python. Strange.

dzaima

@HyperNeutrino That's one thing that java is very good at because it gives errors whenever possible on compication

HyperNeutrino

The thing is I'm using TIO which doesn't give live compiler errors, yet after writing a long segment of code it usually works first try, whereas in Python it usually breaks with some sort of stack overflow, name error, etc. I don't know why ¯\_(ツ)_/¯

Mr. Xcoder

@HyperNeutrino Well that's what happens when you think TiO is an IDE :p

Anonymous

If you like Python and you're working with graphs, you might try NetworkX

HyperNeutrino

2:44 PM

@Mr.Xcoder Hey, you think of a better IDE for a chromebook :P

(Oh wait there are a million and three other online IDEs that have live compiler feedback)

(Such as repl)

@Mego ooh interesting, thanks!

Anonymous

Also that raises an interesting question in the context of the OEIS challenge. We usually consider lang+lib to be a different language than just lang - would that apply to the OEIS challenge as well?

HyperNeutrino

Oh snap interesting question.

That would be awesome.

Mr. Xcoder

ask caird lol

user202729

@HyperNeutrino How could you embed the url into the message?

HyperNeutrino

Just paste it.

anyway gtg for like 40 minutes, I have a math contest to go write.

Mr. Xcoder

2:50 PM

@user202729 Shift+Enter.

user202729

Indeed. Should that be correct?
https://tio.run/##nRldb9s28Nn5FWwfVmtW3KQD9hAnHrZiAwZ0wLBmezHcgbaZRDItaZTsJOu8v57dHb8l2UnXh0bkffC@eUfnfMdPy0oU@Wr99JRtqlI1LIfN8bbJ5Ph7pfhjPTnpAD5kddOzTfgadsIXdaP4smFZ0Qh1w5eC/VCWUvDifblZZIVQ7PPJwGEtNIwtNXBo11LcNKmDquz2rkkmJ/te/j/@teUyax4vr1P2@7SXvUCUenht@P4eclxKXtfsV56pyw8p@40YfGBycjL4jSnQaFBtFzJbEsYQAIDDVIJYg@Yuq8eSXRG2XilYAdVgPxh45r/wrECCuuENcNqV2YpVCjSw@s7msznb8EZlD5rzTamYBzJV3rOLCCHCYAKggGNAg4@PdSM243LbjPUxgn3HzgHnLJn0I7xhbzRof9IDlsWQoAAEnawaXryW92An8h8qgPZOO6FwoyUGGwmIKCQaS1HcNnfs6krTmDWeHnAT9VY2YOlC3LtDAur5xJoQhGcZIJ5N4M@lIbQ8WTYaJWZvls0B7WZsVUFusJdqKeC…

Mr. Xcoder

yes, it works here

user202729

Seems to be wrong.

Oh, too late for deletion already.

New Sandboxed Posts

1

A: Sandbox for Proposed Challenges

Check algebra proofs in a ring The recent proof-golf to prove that (-a)×(-a) = a×a attracted a number of faulty submissions, because there wasn't a way to check the proofs. So, let's write some proof checkers. Your program should take a sequence of strings representing expressions in a ring. Va...

Poke

3:07 PM

I was running a build to roll out to our staging environment and it errored because I guess I ran out of disk space... Half of my allotted storage was taken up by old builds dating back to 2015

fun morning

user202729

The permutation algorithm seems to be correct now. But I get even less graph.
https://tio.run/##nRnbbts29Nn5CrYPqzUrbtIBe4gdD1uxAQM6YFizvRjqQNtMTFmWNEp24nXer2fn8E5dHHd9aESeC8@d59Ap3dPLomR5uto8P/NtWYiapLA53tU8G38vBD1Uk4sW4AOv6o5tia9gF3RR1YIua8Lzmol7umTkh6LIGM3fF9sFz5kgny8GFmuhYGSpgEOzzth9HVuo4A/rOppcHDv5//jXjma8PkzvYvL7rJM9Q5RqeKf5/u5zXGa0qsivlIvph5j8Jhl8INnkYvAbEaDRoNwtMr6UGEMAAA4REWIN6jWvxhm5ldhqJWAFVIPjYOCY/0J5jgRVTWvgtC/4ipQCNDD6zpN5Qra0FvxJcb4vBHFAIopHchMgBBiEARRwNGjw8VDVbDsudvVYHcPId@QacK6iSTfCG/JGgY4XHeAsH0ooAEEno4YTr@E92An8hwqgveNWKNwricFGDCIKicYZyx/qNbm9VTR6jad73Fi1y2qwdM4e7SEedTIxJ…

Change a.r.length to a.l.length.

But the fish with edge BC is still missing.

user202729

3:40 PM

@hyperneutrino [Does this support case-insensitive @ ?] Without knowing (I can't understand them from reading the code) how your addCycles, isValid, and the matrix structure works (the l is adjacency matrix, but what is the r?) I can't say anything more.

HyperNeutrino

@user202729 I'm not sure which section you're referring to.

user202729

The elements in the pair.

New Sandboxed Posts

4:01 PM

0

A: Sandbox for Proposed Challenges

All the same digits code-golf number-theory integer Task For any integers n, b > 0 there exist infinitely many integers k > 0 for which n * k's representation in base b only contains the digit b-1. This challenge's task is to output the smallest such k for given integers n, b. Input Two inte...

caird coinheringaahing

4:22 PM

I love Jelly (the language) for one reason only: the absurd program flow when doing explanations

Anonymous

@cairdcoinheringaahing J is even worse, with hooks and forks

New Main Posts

4:51 PM

-3

Q: Give me some bits

Problem Write a program that produces 128 specific bits of output. In the simplest case, output those 128 bits in a standard numeric(0,1) form such as sixteen pairs of hexadecimal digits(format as shown in output). Your program may not contain the 128 bits in literal form! Output 00001001 1111...

New Main Posts

5:33 PM

0

Q: Hopping numbers

TASK print integers n, where 12 <= n <= 123456789, and all pairs of consecutive digits in n have the same positive difference between them (e.g. 2468 but not 2469). NO INPUT. Output: 12 13 14 15 16 17 18 19 23 24 25 26 27 28 29 34 35 36 37 38 39 45 46 47 48 49 56 57 58 59 67 68 69 78 79 89 12...

code-golf number kolmogorov-complexity

DJMcMayhem

5:59 PM

Challenge idea: Enumerate all Sudoku boards

caird coinheringaahing

@HyperNeutrino are you still working on the OEIS challenge?

HyperNeutrino

Not currently; I'm in a French lesson right now.

caird coinheringaahing

I still don't understand your schools attitude to phones :P

HyperNeutrino

I'm on a chromebook right now.

I wrote my homework on it as well as like almost everyone else.

Uriel

@DJMcMayhem next in line: enumerate all valid chess boards

HyperNeutrino

6:02 PM

Besides, the school really doesn't care because if you're not learning, that's your problem when tests, exams, and assignments come :P

caird coinheringaahing

@HyperNeutrino You clearly have nicer teachers than me :P

HyperNeutrino

Some teachers would care but right now we're allowed to have chromebooks out :P

(Not always, but sometimes; depends on the current activity)

Anonymous

@Uriel Enumerating all valid chess boards where black is in checkmate would be much more reasonable :P

HyperNeutrino

(Normally I'd'nt've used chat in class but you pinged me :P)

caird coinheringaahing

TIL that "Don't google google" doesn't have a Jelly answer

Mr. Xcoder

6:07 PM

@cairdcoinheringaahing A new challenge to answer :-)

caird coinheringaahing

@Mr.Xcoder Not anymore D:D I just answered it

Mr. Xcoder

You beat me to it

@cairdcoinheringaahing That doesn't mean I cannot outgolf you :D:D

caird coinheringaahing

@Mr.Xcoder Have fun :P 10 bytes to beat

Scrooble

@Uriel next in line: enumerate all valid states of the universe

Gryphon

@Scrooble enumerate all valid states of the multiverse.

HyperNeutrino

6:13 PM

Enumerate all enumerations of all valid states of the universe.

caird coinheringaahing

Final one in line: List the type, mass and position of every fundamental in the multiverse

(I dislike the word "enumerate") :P

DJMcMayhem

@Uriel Ha!

Mr. Xcoder

@cairdcoinheringaahing Dang.... L÷⁻“æ8Ụ»$prints inf instead. Anyway brb

caird coinheringaahing

DJ clearly missed the "chaos" he caused :P

HyperNeutrino

anyway gtg o/

caird coinheringaahing

6:15 PM

@Mr.Xcoder Yeah, Jelly happily divides by 0. That's how good it is :P

@HyperNeutrino Bye o/

DJMcMayhem

@cairdcoinheringaahing What now?

@EriktheOutgolfer I'm not sure I get your comment. 1) By ¶ you mean a literal newline, right? (you never can tell with Jelly :P) and 2) Why is that so much clearer?

Erik the Outgolfer

1) yes

caird coinheringaahing

@DJMcMayhem The constant enumerations of "Enumerate all..."

DJMcMayhem

Oh, I missed that

Erik the Outgolfer

2) because the way you do it rn is a bit hackish

DJMcMayhem

6:18 PM

Well, I'm not sure how or why, I just know that it works. I've never understood the logical and dyads, so it was pretty much CPP (Copy-paste-pray)

But originally, I had >0Ȧ$

Erik the Outgolfer

Eȧ will return the list of deltas if they're all equal, else 0

>0 will then return a list of 1s or a list of 0s if Eȧ returned the delta list, else it will return 0

Ȧ will then return 1 if it's given a list of 1s, else it will return 0

I don't think that's how you intended it to work, is it?

DJMcMayhem

No, I intended (Equal) && (>0 && ALL)

Uriel

@cairdcoinheringaahing well, considering the multiverse is infinite, this is totally doable, given a fitting technology and over infinite time.

caird coinheringaahing

@Uriel How can something be greater than infinite?

Erik the Outgolfer

@DJMcMayhem btw it would still work

so it's not invalid

DJMcMayhem

6:25 PM

Yeah, ik

@EriktheOutgolfer BTW, how exactly does logical and work?

Erik the Outgolfer

short circuit

Mr. Xcoder

@cairdcoinheringaahing (And everyone else that wants to join) Have some time for JHT?

Erik the Outgolfer

like, a if not a else b

caird coinheringaahing

@Mr.Xcoder Yeah, sure :P

DJMcMayhem

Oh. That's totally not what I expected

I was expecting 1 if a and b else 0

mbomb007

6:28 PM

jslint.com/help.html

Erik the Outgolfer

it would have been very inconsistent if it did what you expected :p

mbomb007

> The fat arrow => fart functions.

Now I'm going to think of the => as the fart operator.

5

Anonymous

@cairdcoinheringaahing There are multiple flavors of infinite. See: cardinality

Uriel

@cairdcoinheringaahing well, different infinities can have different cardinalities

Anonymous

The real numbers and integers are both infinite, but there are (infinitely) more real numbers than integers.

Anonymous

6:31 PM

@mbomb007 I feel a great disturbance in the force, as if a million souls snickered and then were silenced.

mbomb007

Not sure if typo, or a prank.

Erik the Outgolfer

I don't think it's a typo?

because why call them "fat" functions?

mbomb007

Could be "for" functions

Erik the Outgolfer

but r is close to t on a qwerty keyboard

@mbomb007 then the typo would be really massive

New Main Posts

0

Q: Find the PPCG username

Input A Programming Puzzles and Code Golf Stack Exchange user ID, in the format of a string or integer. E.g. 53551 Output This user's current username. This may be printed to the screen or returned as a string. Must have proper capitalization, spacing. Rules Standard loopholes are banned, ...