The Nineteenth Byte

@ASCII-only I just started Grade 10, and we've just begun trigonometry.

Its so easy ಠ_ಠ

3:11 PM

Well 1) I'm in Grade 11 Math and 2) That's boring

Group Theory isn't grade-level math geez :P

I would have done it in grade 9 if I was allowed to do both maths at once (well grade 12 maths doesn't exactly have that much abelian groups though)

@HyperNeutrino yeah of course, that's only one year ahead :P

yeah

I mean Grade 10 math was boring af

and kinda stupid

My school doesn't allow you to do further year's subjects (year 10 in year 9 e.g)

This is why you should do grade 10 math in grade 7

I did everything correctly and wrote all steps I thought was necessary but apparently I didn't label them properly and I got 92% ._.

@ASCII-only yup :P

3:13 PM

@HyperNeutrino for what

@cairdcoinheringaahing my school "doesn't" either but they had to deal with 4 people from the same grade 8 class bothering them for over 2 months straight so they eventually gave up resisting

@ASCII-only on a test in Grade 10

@HyperNeutrino In the last math exam, I got 100% without having to show my working, even when the question asks you to. Our school system is messed up.

@cairdcoinheringaahing yes. Yes it is

._.

My Grade 11 math teacher should be slightly if not much better; he's the head of the math department

@HyperNeutrino -1 I get 95% and my mom's gets really disappointed

3:15 PM

k I got a 98 final mark and I was disappointed k

Maths basically is the teacher asking me if I know the topic, and if I do, I just mess around on my graphing calculator for the hour

lol that was me in grade 7/8

A lot of the arithmetic I do isn't "proper"

like I add numbers from left to right

My Grade 10 math teacher had a degree in applied math like ಠ_ಠ

@HyperNeutrino I think we can safely conclude every school system is messed up :P

Yes :P

anyway I gtg now lunch starting now o/

@cairdcoinheringaahing me in grade 9

You don't want to know how many programs I wrote on my calculator that year

3:17 PM

@HyperNeutrino I'm back

I once managed to derail a lesson by asking my teacher a question about dimensional maths and he couldn't prove that I was wrong. He just gave the rest of the class a worksheet and spent the rest of the lesson trying to disprove my proof

oops, you're gone

@cairdcoinheringaahing what was it?

@cairdcoinheringaahing did you write any programs

@ASCII-only I made a list of basic PPCG challenges, then did them in Maths in year 10 :P

@cairdcoinheringaahing on your calculator?

Mayube

3:19 PM

in year 8 the back 30+ pages of my notepad for Art class was filled with BASIC code

like, handwritten, with a pencil

with line numbers

@LeakyNun I can't remember the proof, and it would take ages to find it in my room

@ASCII-only copied them down at home onto the calculator

stuff like Hello, World! and Prime test

@Mayube :|

@cairdcoinheringaahing copied?

@cairdcoinheringaahing what was it that you proved?

@Mayube :| basic

Mayube

it was actually DarkBASIC

3:21 PM

@ASCII-only From this gist

@LeakyNun some perspective thing about 4 dimensional tetrahedrons. I think the proof was that it is impossible to rotate it completely through once so that it turned itself inside out, but still being able to see all internal and external faces.

@cairdcoinheringaahing I don't think I understand that

@LeakyNun TBH, neither really did I :P

@cairdcoinheringaahing 4 dimensional tetrahedrons don't exist

@cairdcoinheringaahing then how could you prove it

@cairdcoinheringaahing also you can't just turn a shape inside out wat

@ASCII-only I didn't say I proved it, I just said that my Maths teacher couldn't disprove it. I have a feeling that if I found the "proof" later in life, I'd laugh at how bad it was

1 min ago, by ASCII-only

@cairdcoinheringaahing 4 dimensional tetrahedrons don't exist

@_@

3:30 PM

@ASCII-only You can in 4d, take a look at this

3:45 PM

@cairdcoinheringaahing uh no? It's not turning inside out

@LeakyNun I'm afraid I don't know from the problem description

@ASCII-only I can turn a 3d shape inside out, why not a 4d shape?

@orlp never mind then :P

remainder 1 mod p seems something in the direction of fermat's little theorem, but I don't know what the purpose of doing it for all divisors of n is, at least at the moment

@LeakyNun no, please do tell :P

see if I recognize it

@AdmBorkBork how.

3:49 PM

@orlp tell the answer?

Suppose you have a pyramid. Pull a point through the opposite face. Voila, turned inside out.

@LeakyNun the "what it is for" part

or maybe a hint

actually

@orlp hint: group theory

@LeakyNun ah

you see

@cairdcoinheringaahing how do you make it go inside out by rotating

3:50 PM

you're a bit of a group theory binge atm, but I know a lot less about it than you seem to think :p

@orlp alright then

Wow, atm tnb is surprisingly similar to M.SE chat

@LeakyNun so, what is it for?

@orlp Sylow's third theorem

nope, I can safely say that I'm not familiar with it

I'm more of a computer scientist and engineer than I am a pure mathematician

3:54 PM

Given a group with $p^nm$ elements where $p\not\mid m$, then the number of subgroups with $p^n$ elements $\equiv 1 \pmod{p}$ @orlp

I know a thing or two, but I'm definitely not familiar with most things

@LeakyNun I saw in your profile btw, good luck at your new uni :)

@orlp thanks

you're not that far from me now, just across the pond, we could meet up sometime :D

@orlp that would be a good idea

CMC: Given an integer, output the result of the prime number theorem applied to the given integer.

3:58 PM

@Mr.Xcoder but the prime number theorem isn't a function

@Mr.Xcoder too vague

did you mean the prime counting function?

Yes

Sorry

The one that states that pi(N) ~ N / log(N)

Sorry, bad wording.

so you just want us to return N / log(N)?

yes

jelly, 3 bytes: ÷Æl

4:00 PM

Untested (not sure if these are the correct built-ins), Pyth, 6 bytes: /Q.lQT

pyth, 4 bytes: cQ.l

and no / is integer division

wait you want ln or log10?

then

@Mr.Xcoder what?

oh

l wanted ln but said log10

tell me guys

Dumb me

4:02 PM

give me a logical reason why the number of primes below a certain number

your pyth solution does log10 btw

would have anything to do with the number "10"

that's why I asked

@EriktheOutgolfer yes, I don't know the built-ins.

And I messed it up

it's cQ.l

4:03 PM

@LeakyNun you know what I realized a while back

I always didn't like the geometric mean

@EriktheOutgolfer An integer cannot have a floating point number of ways it can be expressed as the sum of primes.

wikimedia.org/api/rest_v1/media/math/render/svg/…

@Mr.Xcoder nothing can ever have a floating point number of ways

it's like, "the 2.5 ways of cleaning your house"

it's always introduced as the nth root of the product of numbers

@EriktheOutgolfer then why would you use c?

4:04 PM

which seems so arbitrary

@Mr.Xcoder logarithms are floating-point

but I realized that there's (to me) a much more natural explanation

it's the average of the logarithms of the numbers, which is then exponentiated back at the end

to me that makes infinite more sense

it's easier to compute

@orlp I'd say it's about the same

@ASCII-only really?

if I give you 100 numbers

what do you think is easier

make a giant product of them, and then compute the 100th root on that?

or just take the log of each number, sum them, divide by 100 and exponentiate once?

Depends on the accuracy you want

And the cost of log and exp

4:08 PM

for example, the geometric mean of [1, 2, ..., 100]

with the root method you have to compute the 100th root of 100!

@ASCII-only what is the 100th root of

9332621544394415268169923885626670049071596826438162146859296389521759999322991‌5608941463976156518286253697920827223758251185210916864000000000000000000000000

?

and this only gets worse with bigger numbers

with 1..100000 I just have to do one log per input number and sum

meanwhile you have to find out algorithms to accurately find the 100000th root from 100000 factorial

@orlp congrats on 100k

network-wide :p

oh didn't even realize

that's network wide though

@orlp well it doesn't have to be full precision

officialaimm

@EriktheOutgolfer kolakoski question is tearing my brains out... Anyone williing to try and fix this?

4:18 PM

there should be no "thu"s right?

But I guess with log you're working with much smaller numbers, not sure how much that helps

@ASCII-only a lot

besides

if it doesn't have to be full precision

the log based solution can also just do a very rough approximation of log

officialaimm

@EriktheOutgolfer Yea, I am going index out of bounds on those condition, I couldn't neither figure out how nor fix it..

you don't account for leading 1s

officialaimm

@EriktheOutgolfer Oh, yea... It's failing on lists beginning with 1...

4:23 PM

@orlp yeah, just saying doing it the naive way isn't necessarily easier :P

*more difficult

@ASCII-only except it is

try to write a correct program that computes the geometric median in both ways

4:48 PM

@orlp *mean?

oops, yeah

Any language?

I'd suggest a 'regular' language, such as Python, C, C++, Java, etc, not a golfing language

tio.run/##PcqxCgIxDIDhvU@RMS0BqbcJ9yTi0KHnFdIk1Jzo01cHcf2/…

Maybe?

Limited precision shouldn't be too hard with the decimal module

Need to go to sleep now so I'll be done for up to 9 hours

5:15 PM

@ASCII-only oops: tio.run/##Pcq7DsIwDIXhPU/…

A: Sandbox for Proposed Challenges

the mathematics room has had a lot of flags today...

New Sandboxed Posts

0

Do the line segments cross? Description: Today, we're going to do some geometry: We have two line segments and want to find out where they cross! A point is a pair of two integers being the x and y coordiantes of said point. If your calculations result in non-integers, you continue with the inte...

CMC: given a string of brackets, return the minimum number of additional characters needed to make it valid brain-flak code

() --> 0

{{{} --> 2

@DJMcMayhem cookies to anyone who does it in brainflak :P

Wait a second....

5:27 PM

@DJMcMayhem What is it?

Oh wait, nevermind

I'm dumb

I thought inputs like (] would cause problems, but that would give 2

wait

so...

it's not simply open brackets - close brackets

Yeah, that wouldn't work because not all brackets match eachother

And they might be in the wrong order too, so )( should give 2

@EriktheOutgolfer No, but a solution would be something along the lines of |number of open brackets - number of close brackets| (I think)

no

5:30 PM

@cairdcoinheringaahing That would still fail for )( and (]

A: Sandbox for Proposed Challenges

@DJMcMayhem Yeah, just realised that ^^^ is a gross oversimplification of the actual method

New Sandboxed Posts

0

Prime Number Locator Given a prime number p > 1, determine at what index p appears in A000040. You may 0 or 1 index, meaning 2 can return 0 or 1. If you are given a non-prime number you must return -1. If you are 1-indexing you may return 0 instead, or still return -1. Your time complexity ...

Hmmm. How do you do not preceded by in regex?

@DJMcMayhem Python 3, 157 bytes: Try it online

Can definitely be golfed

@DJMcMayhem ?!< I guess?

(lookbehind)

> x=[0,0,0,0]

oh wait

same-reference?

oh huh no

5:40 PM

Hmmmm

H.PWiz

@cairdcoinheringaahing, fails for ")("

@EriktheOutgolfer Aha! I can do it with \@<! in vim

what is \@<!

like, the \@ part

The \@ generally just occurs in look(ahead|behind)s

							*/\@<!*
\@<!	Matches with zero width if the preceding atom does NOT match just
	before what follows.  Thus this matches if there is no position in the
	current or previous line where the atom matches such that it ends just
	before what follows.  |/zero-width| {not in Vi}
	Like "(?<!pattern)" in Perl, but Vim allows non-fixed-width patterns.
	The match with the preceding atom is made to end just before the match
	with what follows, thus an atom that ends in ".*" will work.
	Warning: This can be slow (because many positions need to be checked

And \@! is a not match (with zero-width) but at the current position

V, 44 bytes: Ø()À!ü(À<!)ü[]À!ü[À<!]ü{}À!ü{À<!}ü<>À!ü<À<!>, can definitely be golfed

Using kolmog to build/then execute that code saves 7 bytes: Try it online!

But there might be a more efficient kolmog approach

Hmmmm

Using a macro instead of a regex only saves 1 byte: O()[]{}<>|òä2laÀ!ülaÀ<!láülòxÉØD@

6:00 PM

Ugh, new user post on main

What's even worse, is that they have a stack overflow account, but still ask for help here.

@DJMcMayhem I don't know if this would be valid for 104 Python bytes

38 mins ago, by DJMcMayhem

@cairdcoinheringaahing That would still fail for )( and (]

Ugh

Then I have about 130 bytes

@Mr.Xcoder That's invalid, so it doesn't matter, but you could significantly golf that down: Try it online!

I know I can use sum

I just wondered if that would be valid.

6:22 PM

CMC: Given a (square) matrix of integers, return the deltas on the integers of each column.

[[1,2,3],[2,3,4],[4,5,6]] -> [[1, 2], [1, 2], [1, 2]]

BTW it's 2 bytes in jelly

And 5 bytes in Pyth

2EZ 4RTZ

@Downgoat memoryofgod.itch.io/where-the-goats-are it is free too

the deltas of*

> Hi {leadfirstName},
I want to touch base with you to see if {companyname} would be willing to have a 15 minute face to face on {date}, to talk about your long-term storage needs?

Spam email I just received. I think someone doesn't know how to mail merge.

2EZ 4RTZ

Haha

6:46 PM

@AdmBorkBork You're assuming that they didn't mean to send it to {leadfirstName}. I hear that guy's very popular amount incompetent email spammers. :P

Q: programminng game school project

Ah yes, the venerable and well-respected {companyname}. I love using their {product}.

muddyfish

jinja2 works very nicely for email as well

New Main Posts

-5

Hi so i got an assingment to do a mathimatical game in school and i would need some help cause i started programming c++ 4 days ago and im not that experienced yet to do something likes this. basicly its Make a program using c++ that manages a calculation game where two people compete against ...

7:09 PM

How do these people a) find this site and b) think it's a good place to post this stuff? Maybe I'm just too cautious myself and lurk a lot before posting anything.

I think I might be able to take several hundred bytes off my brain-flak answer

Welp.

I golfed 100 off

It's a start

7:35 PM

@AdmBorkBork good question. I think this question is doomed anywhere including SO because "gimme teh codez" :P

Poke

8:23 PM

@DJMcMayhem 100 is definitely a good start to multiple hundreds

@Poke Yeah, I'm definitely really proud of my progress (especially since my answer is 8 months old)

But it's frustrating cause it takes like an hour of work to golf anything off

Poke

that seems to be how it goes for languages like that

(FTR, I'm talking about this answer)

Well, it's also an obscenely long answer

I bet it could get under 700

Oh hey, I updooted that answer, probably because of the extensive explanation.

:D

Did you read the commented version too?

8:32 PM

Commented version?

Yeah, I linked to a commented version on gist because it's ridiculously long

> I have a detailed explanation, but it's about 6 thousand characters long, so I think it would not be wise to paste the entire thing into this answer. You can read through it here if you want. I'll add a shorter explanation here.

Although now it's more like 7.3 thousand

8:50 PM

→ 19 messages moved to The Nineteenth Stack

Q: Language Agnostic Code Golf!

o interesting

so many 19 D:

also I decided to hold off making another "practical" programming language for now

instead I'm attempting to make the world's least syntactically strict programming language :P

It has a lot of regex with a lot of .* :P

New Main Posts

10:25 PM

0

Don't you ever want to know if your code golf score is "good enough" for the language you're using? How can you measure which golf is better when one is in Jelly and one is in JS? Well, now we can! Task Take two programming language names as input. Find 40 code-golf questions that have at least...

code-golf stack-exchange-api

Helka Homba

Should there be a comma in sentence "At last update, I was living in the sea."?

Q: Gimli, make it even shorter?

hello

SEJPM

evenin' @biv ;)

Thomas Ward

@HelkaHomba sounds like ELU is where this needs to go heh

New Main Posts

0

I'm one of the author of Gimli. We already have a tweetable (280 chars) version in C but I would like to see how small it can get. Gimli (paper,website) is a high speed with high security level cryptographic permutation design that will be presented at the Conference on Cryptographic Hardware an...

code-golf cryptography

10:39 PM

@SEJPM I just spent 3 hours code golfing that Gimli because my supervisors wanted a "short" version.

SEJPM

@Biv well, at least that's a case of "has shown significant prior research effort" ;)

especially as unpaid work :D

SEJPM

@Biv well, gotta work on your contract / attitude if you want to avoid unpaid work in the future ;)