The Nineteenth Byte

El'endia Starman

12:10 AM

@flawr: Updated the syntax spec!

New Main Posts

2

Q: Simplify a square root

Given a positive integer n, simplify the square root √n into the form a√b by extracting all square factors. The outputted a,b should be positive integers with n = a^2 * b with b as small as possible. You may output a and b in either order in any reasonable format. You may not omit outputs of 1 ...

New Main Posts

12:26 AM

0

Q: Ninja Assassins - which ninja stays alive?

Ninja Assassins - which ninja stays alive some basic information given an int N as the number of ninjas, return the number of the winning ninja. At the end only 1 ninja survives,the question is which one? what was his number?. Each ninja kills the ninja who stands after him. Afterwards, he pas...

code-golf code-challenge fastest-code

quartata

12:37 AM

I recently saw in a bookstore a JS book that said "how to code safely in the world's most dangerous language"

if that isn't a turn off I don't know what is

Cᴏɴᴏʀ O'Bʀɪᴇɴ

12:49 AM

I'm cringing right now. Watching Bruce almighty

PhiNotPi

1:13 AM

@CᴏɴᴏʀO'Bʀɪᴇɴ Better than Evan Almighty.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@PhiNotPi true

PhiNotPi

TBS, I thought Bruce Almighty was very educational about religion and spirituality, and about man's relationship to God. /s

TBS = to be sarcastic

Interesting domain name for sale, 3.cymru

El'endia Starman

@PhiNotPi I actually consider Bruce Almighty to be more of a Christian movie than most movies that are explicitly (labeled as) Christian.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

Just finished it. nice movie

PhiNotPi

1:29 AM

@El'endiaStarman TBH, it's been a long time since I've seen either of them.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@PhiNotPi I thought you were making a joke

By cringing, I meant, plot-wise.

PhiNotPi

@CᴏɴᴏʀO'Bʀɪᴇɴ Evan Almighty is a very real movie.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@PhiNotPi I just looked at it

PhiNotPi

Another interesting domain for sale: s.et I'm not even sure how it's for sale, since according to all sources I can find second-level .et aren't available.

Leaky Nun

@PhiNotPi how is that a domain for sale has a logo?

PhiNotPi

1:34 AM

@LeakyNun People like to make logos to promote their domain name. Cool logo = more interest, apparently.

Leaky Nun

I see

PhiNotPi

@LeakyNun check this out: brandbucket.com/category/4-letter-domain-names

lots of logos there

Leaky Nun

wow

Cᴏɴᴏʀ O'Bʀɪᴇɴ

that could be a potential pop-con: generate distinct 4-letter logos :P

Dr Green Eggs and Iron Man

CMC: Write a CMC that is a duplicate of another challenge

PhiNotPi

1:44 AM

CMC: Write a CMC that is a duplicate of another challenge

Cᴏɴᴏʀ O'Bʀɪᴇɴ

CMC: Write a CMC that is a duplicate of another challenge

El'endia Starman

Okay that's enough. :P

Leaky Nun

CMC: Write a CMC that is a duplicate of another challenge

Cᴏɴᴏʀ O'Bʀɪᴇɴ

12 secs ago, by El'endia Starman

Okay that's enough. :P

Geobits

VTC as too broad, duplicate, unclear what you're asking

El'endia Starman

1:45 AM

*smacks Leaky Nun with a salmon*

Cᴏɴᴏʀ O'Bʀɪᴇɴ

hey, does this remind anyone of that xkcd what if, "how many possible tweets are there?"

Leaky Nun

@CᴏɴᴏʀO'Bʀɪᴇɴ 1114112^140

El'endia Starman

@LeakyNun That's not what Randall calculated.

Link to it: What-If: Twitter

Leaky Nun

I see

Geobits

He's trying to calculate English, which is about impossible.

El'endia Starman

1:47 AM

I think his estimate is about as close as you can get, though.

xnor

is there a nice bit hack to convert all non-leading zeroes to ones?

i.e. 10100 -> 11111

Leaky Nun

> Based on the rates of correct guesses—and rigorous mathematical analysis—Shannon determined that the information content of typical written English was around 1.0 to 1.2 bits per letter. This means that a good compression algorithm should be able to compress ASCII English text—which is eight bits per letter—to about 1/8th of its original size. Indeed, if you use a good file compressor on a .txt ebook, that’s about what you’ll find.

omg

@xnor in which language?

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@LeakyNun have you tried doing PE with J? It's wonderful

Leaky Nun

@CᴏɴᴏʀO'Bʀɪᴇɴ and what is PE?

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@LeakyNun I think he's just generally talking about bits

@LeakyNun project euler, sorry

xnor

1:48 AM

@LeakyNun python, or anything with C-style bit arithmetic

Leaky Nun

@CᴏɴᴏʀO'Bʀɪᴇɴ not really

@xnor it involves loops

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@xnor basically, round up to the next power of two minus 1?

Leaky Nun

pseudocode:
for(int i=1; 2^i < n; i++){
    n |= n>>i;
}

xnor

@LeakyNun basically, yes

Leaky Nun

pseudocode:
antibin("1"*len(bin(n)))

xnor

1:51 AM

@LeakyNun it was exactly this conversion I was trying to avoid because it's lengthy in Python

Leaky Nun

@xnor i*=2 instead of i++ for faster performance

xnor

is there a nice criterion for what functions can be computed in bit arithmetic expressions?

maybe something of bounded circuit depth?

Leaky Nun

@xnor every

Cᴏɴᴏʀ O'Bʀɪᴇɴ

can you make a function that makes children

El'endia Starman

@CᴏɴᴏʀO'Bʀɪᴇɴ If there were, you know someone would stupidly put it inside an infinite loop, and boom, extreme overpopulation!

xnor

1:53 AM

@LeakyNun how? I'm assuming only +, -, and, or, flip, and shifts

Leaky Nun

@xnor
2**len(bin(n))/2-1

Cᴏɴᴏʀ O'Bʀɪᴇɴ

~~isn't that china~~

Geobits

@CᴏɴᴏʀO'Bʀɪᴇɴ People are functions that make children.

Leaky Nun

@xnor isn't every operation bitwise in its purest form?

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@Geobits I guess the question now is when/if each of us are going to make one of those functions

xnor

1:54 AM

@LeakyNun i imagine they can involve conditionals or loops, whereas I'm looking for pure arithmetic

Geobits

@CᴏɴᴏʀO'Bʀɪᴇɴ Already did mine. Someone else's turn.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@Geobits I'll wait at least a decade before taking my turn

Geobits

Please do :P

Leaky Nun

@xnor I see.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

0

A: Sandbox for Proposed Challenges

Language succession answer-chaining string Given two words (two strings of lowercase-only letters separated by a space) as input to a program PX written in language X, output two programs in languages Y and Z such that program PY outputs the first word and program PZ outputs the second word. Yo...

^ any more feedback? upvote if you think it looks okay

Leaky Nun

2:06 AM

@xnor shit

I just helped you golf your algorithm

xnor

@LeakyNun oh man. how do you do it?

Leaky Nun

lambda n:n&n*2|1 — Leaky Nun 35 secs ago

@xnor

precedence abuse at its best

xnor

that returns 1 for 5?

Leaky Nun

why?

oh, right

@xnor

lambda n:int(bin(n)[3:],2)+1 — Leaky Nun 23 secs ago

xnor

you need to start with a 2*, which gives the same length

Leaky Nun

2:12 AM

oh, right

xnor

and it fails for 1 because int refuses empty strings, even though they are clearly 0

my current solution came from that :)

Leaky Nun

nice

Dennis

2:43 AM

@xnor I was wondering if you saw this comment.

Sp3000

@xnor Finite number of operations?

Leaky Nun

@Sp3000 constant number of operations

xnor

@Dennis oh yes, the trick of spreading the +n over all the loops is quite nice

i was playing around trying to see if I could do better

looks like not

i'll edit in your improvement

@Sp3000 yes

Dennis

@DrGreenEggsandIronMan I'll add it as soon as my internet starts to behave. My SSH connections keep dying...

LegionMammal978

Is it just me, or did they remove the blue from the PPCG's color scheme?

Sp3000

2:57 AM

@xnor Got nothing :( not even sure if there's a good one for next power of two or leftmost bit

PhiNotPi

@LegionMammal978 where?

xnor

@Sp3000 yes, i suspect there's some invariant they all satisfy that stops you from doing anything too interesting

PhiNotPi

I still see blue everywhere, unless you're talking about something specific.

xnor

@Sp3000 I have a fuzzy idea of a candidate: you can parallelize two operations by putting them in far-off place values separated by sufficiently large gaps of zeroes

Sp3000

Problem then is whether you can, say, combine the two separate results

xnor

3:02 AM

@Sp3000 i'm suggesting this as a limitation, that you can't get the next power of two because it would have to do it separately for each "island", which doesn't combine right into result for the combination

Sp3000

Hm k...

Leaky Nun

May 26 at 11:04, by Leaky Nun

Chat mini-challenge: implement the set theoretic definition of the natural numbers (starting from 0).

You will be given a non-negative integer, and you should return the set-theoretic notation of it.

0 is defined as {} (the empty set), and n+1 = n ∪ {n}.

Therefore, 1 = 0 ∪ {0} = {} ∪ {{}} = {{}}.

2 = 1 ∪ {1} = {{}} ∪ {{{}}} = {{},{{}}}

Should I post this in main?

xnor

@LeakyNun it's a dupe, i remember doing it

Sp3000

I'm fairly sure that's a dupe of something

Leaky Nun

10

Q: Set Theoretic Arithmetic (+ and *)

Set Theoretic Arithmetic Premise There have been a couple challenges already that involve multiplying without the multiplication operator ( here and here ) and this challenge is in the same vein (most similar to the second link). This challenge, unlike those previous, will use a set theoretic...

fastest-code set-theory

this?

xnor

3:04 AM

16

Q: Length of String Using Set Theory

From Wikipedia Set-theoretic definition of natural numbers The set N of natural numbers is defined as the smallest set containing 0 and closed under the successor function S defined by S(n) = n ∪ {n}. The first few numbers defined this way are 0 = {}, 1 = {0} = {{}}, 2 = {0,1} = {{},{{...

code-golf math restricted-source arithmetic set-theory

Leaky Nun

16

Q: Length of String Using Set Theory

From Wikipedia Set-theoretic definition of natural numbers The set N of natural numbers is defined as the smallest set containing 0 and closed under the successor function S defined by S(n) = n ∪ {n}. The first few numbers defined this way are 0 = {}, 1 = {0} = {{}}, 2 = {0,1} = {{},{{...

code-golf math restricted-source arithmetic set-theory

ninja'd

CMC: Partition function

Reference: oeis.org/A000041

Duplicate: codegolf.stackexchange.com/q/11654/48934

@CᴏɴᴏʀO'Bʀɪᴇɴ C_BU

Sp3000

Off by one error :P

Leaky Nun

@Sp3000 Oops, C_B+U

@CᴏɴᴏʀO'Bʀɪᴇɴ Jelly: E

Dennis

@DrGreen brain-flak.tryitonline.net/…

Dr Green Eggs and Iron Man

3:22 AM

@Dennis Thanks! I really appreciate it!

Dennis

np

user215373

hi

Leaky Nun

@Dr.ZOMBOOS welcome back

user215373

hmmm

Dennis

@DrGreenEggsandIronMan Btw, your interpreter currently requires you to run it from its directory.

Leaky Nun

3:23 AM

@Dr.ZOMBOOS join our site! ppcg.SE

user215373

ok

user215373

joined it!

Dr Green Eggs and Iron Man

Oh haha. V has the same problem

Leaky Nun

@Dr.ZOMBOOS welcome

Dr Green Eggs and Iron Man

Next time I put a language on TIO, I'll test it from another directory.

Dennis

3:28 AM

Not a problem for TIO (I have to write a wrapper anyway), but it would be nicer in general.

Leaky Nun

CMC: Giving an array of positive integers and a number n, split the array into different bins so that the sum of each bin is as evenly distributed as possible

Dr Green Eggs and Iron Man

In general, what do you think the solution to that is? Is defining a system variable overkill?

El'endia Starman

@LeakyNun Isn't that the knapsack problem? Or subset sum problem?

Sp3000

Define: "evenly distributed as possible"

Leaky Nun

@Sp3000 the variance is smallest

Actually: CMC: variance.

Dr Green Eggs and Iron Man

3:47 AM

What do you mean? Example plz

Leaky Nun

given an array of positive integers, compute its variance

Variance

In probability theory and statistics, variance is the expectation of the squared deviation of a random variable from its mean, and it informally measures how far a set of (random) numbers are spread out from their mean. The variance has a central role in statistics. It is used in descriptive statistics, statistical inference, hypothesis testing, goodness of fit, Monte Carlo sampling, amongst many others. This makes it a central quantity in numerous fields such as physics, biology, chemistry, economics, and finance. The variance is the square of the standard deviation, the second central moment...

example: [1,2,3,4,5,6] -> 35/12 (or floating point)

Pyth: .Om^a.OQd2

Upgoat

4:02 AM

@Quill Hello (even though I don't remember joining the room at that time)

Dennis

@LeakyNun kdb+, 3 bytes: var

Leaky Nun

@Dennis alright

Dennis

Jelly, 8 bytes: S÷L¶_Ç²Ç

Cᴏɴᴏʀ O'Bʀɪᴇɴ

quick question. how can I prove that (a+b) mod n = (a mod n) + (b mod n)?

Leaky Nun

@CᴏɴᴏʀO'Bʀɪᴇɴ 0 = (3+5) mod 8 =/= 3 mod 8 + 5 mod 8 = 3 + 5 = 8

Dennis

4:11 AM

You're missing a mod n on the right side.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

yes that

Upgoat

@zʏᴀʙiɴ101 maybe we should do what CR did and create another room for off-topic chatter and leave this room for code golfing.

Leaky Nun

@CᴏɴᴏʀO'Bʀɪᴇɴ Let a = q1 n + r1, b = q2 n + r2, then a+b = (q1+q2)n + (r1+r2)

something along this line

Cᴏɴᴏʀ O'Bʀɪᴇɴ

nicd idea. thnks

Leaky Nun

,410 ,742 <-- this is the number of voters who voted for UK to leave EU

Upgoat

4:23 AM

@zʏᴀʙiɴ101 glad you enjoyed it

Dennis

Code Golfer's Corner

Discussion specific to golfing code. For general PPCG chatter ...

Quill

Please no. It turned out bad

Upgoat

oh ok

Quill

There's no non-sitebusiness talk in CR chat anymore without someone saying "let's move it"

or the conversation being like five messages

Upgoat

what's wrong with moving it?

Quill

4:32 AM

@LeakyNun I don't have my TI-84 with me, but it'd be like 9 bytes in TI-Basic

Leaky Nun

@Quill which 9?

Quill

@Upgoat then the chat can't hold conversations without being moved

@LeakyNun I wrote similar code a while ago, and I remember it being particularly small

Upgoat

@Quill btw, I want to get v0.3 of Cheddar out but the tests aren't working (seems to be either babel-node or babel-istanbul), is there a way to make istanbul just return 100% so I can merge them?

Quill

uh, no. you can't fake test coverage

Upgoat

5:03 AM

I'm not trying to fake it. I'm just trying to manually set it

Dr Green Eggs and Iron Man

I'm not trying to do "x', I'm trying to do the letter after "w".

3

New Sandboxed Posts

7:01 AM

0

A: Sandbox for Proposed Challenges

Stacks and Stacks and Stacks... Write a program that, with the input as n, finds the first n-gonal and n-gonal pyramid number that is NOT 1. n is guaranteed to be larger than or equal to 3. Examples: n = 3: 10 n = 4: 4900 n = 2: The output can be nothing, False, or anything that you want, ju...

Quill

7:43 AM

Live Crickets 60min "Natural Sound"

►

zʏᴀʙiɴ101

Hello

@Upgoat I'm interested, what's the config for the gource command?

Quill

it's on the readme.md for gource's wikipedia page

there's not much config needed, unless you wanna speed it up

zʏᴀʙiɴ101

I mean, how did the gource command looks.

Quill

I'm confused ;-;

zʏᴀʙiɴ101

I'm about this

zʏᴀʙiɴ101

8:15 AM

@Quill do you like rubber ducks as pictures on the screen? :3

Quill

depends whether those rubber ducks have the Code Review logo on them

zʏᴀʙiɴ101

@Quill This one, sadly, doesn't.

In the meantime, if you still do like rubber ducks not from Code Review as pictures on the screen, there's a giveaway of one.

in Sandbox, 13 hours ago, by zʏᴀʙiɴ101

+-+-+-+-+       0 - NotPunchedYet
|█|█|█|3|       1 - ProgramFOX
+-+-+-+-+       2 - DanPantry
|4|5|6|█|       3 - NotPunchedYet
+-+-+-+-+       4 - NotPunchedYet
|8|█|A|█|       5 - NotPunchedYet
+-+-+-+-+       6 - NotPunchedYet
|█|█|█|█|       7 - FOX9000
+-+-+-+-+       8 - NotPunchedYet
9 - FOX9000     A - NotPunchedYet
B - ConorOBrien C - DanPantry
D - Mast        E - ProgramFOX
F - ConorOBrien

I checked--both Gource and Logstalgia work!

:D

New Main Posts

8:47 AM

0

Q: Brainfuck cat - encode a file as a brainfuck program

Challenge Implement a program that satisfies the man page below: Name bfcat - even more useless than useless use of cat. Synopsis bfcat <FILE> Description Given a FILE, bfcat writes to standard output a Brainfuck source file. The outputted source file satisfies the following conditions: ...

brainfuck

flawr

9:29 AM

@El'endiaStarman If you already have function chaining, you need to make currying a thing + pointless notation a thing! =)

zʏᴀʙiɴ101

@flawr Do you like rubber ducks as pictures on the screen? =)

flawr

I like spaceshuttles way better. I have a relative who is a rubber duck collector.

zʏᴀʙiɴ101

And he's not on SE? :(

flawr

Nope

zʏᴀʙiɴ101

D:

flawr

9:37 AM

I don't think so

zʏᴀʙiɴ101

In the meantime, there's a giveaway of a rubber duck as a picture on the screen.

flawr

zʏᴀʙiɴ101

in Sandbox, 14 hours ago, by zʏᴀʙiɴ101

+-+-+-+-+       0 - NotPunchedYet
|█|█|█|3|       1 - ProgramFOX
+-+-+-+-+       2 - DanPantry
|4|5|6|█|       3 - NotPunchedYet
+-+-+-+-+       4 - NotPunchedYet
|8|█|A|█|       5 - NotPunchedYet
+-+-+-+-+       6 - NotPunchedYet
|█|█|█|█|       7 - FOX9000
+-+-+-+-+       8 - NotPunchedYet
9 - FOX9000     A - NotPunchedYet
B - ConorOBrien C - DanPantry
D - Mast        E - ProgramFOX
F - ConorOBrien

flawr

What is this?

zʏᴀʙiɴ101

in Sandbox, 17 hours ago, by zʏᴀʙiɴ101

I have a rubber duck. I'm going to give it away to the person who guesses the right hexadecimal digit.

Apply in the Sandbox.

(Note: the duck will be provided as a picture on the screen.)

Optimizer

10:06 AM

oh, then I can save it anyways

zʏᴀʙiɴ101

I'm learning with the new SEDE tutorial. Here's my first tutorial query: data.stackexchange.com/stackoverflow/query/504298/…

This query casually touches WHERE and parameters.

flawr

10:22 AM

@zʏᴀʙiɴ101 I don't get it. It seems all digits have already been guessed?

zʏᴀʙiɴ101

@flawr Nope.

When the punchcard is fully punched, the result will be announced.

A concise edition of my first tutorial query: data.stackexchange.com/stackoverflow/query/504681/…

So, how the query works:

SELECT ==> Top (Cost: 0%) ==> Clustered Index Scan / [PostsWithDeleted].[UIX_PostsWithDe... (Cost: 421994%)

That is the execution plan.

Also, WTF? 421994%? o_O

Quill

10:52 AM

The Raspberry Pi magazine is called MagPI.....

zʏᴀʙiɴ101

@Quill That's a reference to Alex A.!

Quill

It's a bad joke from RPi

zʏᴀʙiɴ101

11:27 AM

Got +necromancer!

Your answer is invalid, as the highest snippet length, 2, is larger than 1. You have to delete every snippet longer than 1. — zyabin101 8 secs ago

Or have a person with rollback delete these snippets.

@Quill do you have rollback? >_>

Quill

I don't have rollback privs on Code Golf

my rep is too low

zʏᴀʙiɴ101

D:

On the same question, I have updated the UGL answer! :D

trichoplax

Is anyone else affected by this? It affects PPCG for me, but I'm not sure if it's site specific or user specific

zʏᴀʙiɴ101

@cc @LeakyNun

orlp

What is 0^i?

trichoplax

11:42 AM

@orlp Surely 0, although I confused myself with powers of i the other day so I will wait for someone who knows what they are talking about...

@orlp Python 3 says ZeroDivisionError

It points out that you can't raise 0 to a negative power (understandable as that would be dividing by zero) but also you can't raise zero to a complex power, which I don't know the reason for

mınxomaτ

@trichoplax This has always been like this. The host parameter prioritizes the site-specific rooms in the list (i.e. they'll appear first).

trichoplax

Ah....

Thank you

@mınxomaτ Would you like to post an answer with that, or shall I answer quoting you?

mınxomaτ

Do it, I'm lazy :P

trichoplax

:)

Doorknob

12:11 PM

@trichoplax WolframAlpha agrees

trichoplax

I still can't find an intuitive reason for why all complex numbers would give an undefined result (apart from those with imaginary part zero). I might ask on math.SE

flawr

@El'endiaStarman youtube.com/watch?v=sULa9Lc4pck

3

(just the corrected version)

@trichoplax The question probably is more on how you define a^b in the first place

trichoplax

So maybe I need to ask if there is a consistent way of extending the definition?

flawr

I have no answer yet, but usally a^b is defined via e^(b*log(a))

where e^x = exp(x) = sum x^k / k!

and log(x) is just the inverse power series of exp(x) (inverse wrt composition)

on the other hand if b is rational, you do not have to use exp and log

Leaky Nun

@zʏᴀʙiɴ101 nice

@orlp a^b is really exp(b*ln(a)), where exp is exponential and ln is natural logarithm

in this case, ln(0) is undefined

if i'm correct, lim(z->0) ln(z) = lim(r->0) ln(r)+i*theta = -infinity (it means no matter which direction you come from, ln(0) approaches -infinity)

flawr

12:27 PM

@LeakyNun It does not have to be that way.

Leaky Nun

@flawr it is defined to be that way

flawr

There is actually an interesting read (not exactly what we are looking for) on 0^0 : en.wikipedia.org/wiki/…

Leaky Nun

at least that is how we extend it to the real numbers and the complex numbers

flawr

@LeakyNun Always depends on the context

Different approaches have different definitions

Leaky Nun

@flawr how does your link contradict me?

flawr

12:28 PM

Luckily for practical purposes they agree, but when it comes to pathological cases, they might indeed differ

Sp3000

Hmm...

trichoplax

@flawr I hadn't seen that before. It is beautiful. I like that they give attribution in the description to the math.SE post too.

Sp3000

(I have no idea why Wolfram's trying to take a 2-sided limit there)

flawr

@LeakyNun Look at the different justifications on 0^0

Leaky Nun

@flawr 0^0 is undefined, but you can assign values to it so that it makes sense in other contexts

just like how you assigned 0! to be 1

because it is convenient

flawr

12:31 PM

@LeakyNun Well that is just true if you assume the definition you just used

But different fields might consider different values as convenient

Leaky Nun

@Sp3000 I don't know what (x->i) even means. from which direction are you approaching i? usually we only approach a limit from the left or the right, but you're making it complex

flawr

my point is that there might be no "true" convention, but it is always a matter of perspective and a matter of what you defined

Eric Tressler

0^0 is often defined

mınxomaτ

@flawr 0^0 is very convenient: 255.wf/FormulaCompiler

Sp3000

@LeakyNun I don't think a two-sided limit is sufficient for the complex plane, hence why I'm confused by Wolfram's result attempt

Leaky Nun

12:34 PM

@Sp3000 so you tried to break it

Eric Tressler

what is going on?

Leaky Nun

we derailed from 0^i to 0^0

wolframalpha.com/input/?i=lim_(x-%3E0)+x%5Ei

Eric Tressler

It's usually just taken to be 1 by convention.

flawr

@mınxomaτ I don't really get it, what is it supposed to do?

@EricTressler Not always

mınxomaτ

@flawr Read the proof.

Leaky Nun

12:38 PM

@EricTressler by which convention?

Eric Tressler

@flawr That's what USUALLY means

flawr

@EricTressler As aslways, it heavily depends on the field=)

Exponentiation

Exponentiation is a mathematical operation, written as bn, involving two numbers, the base b and the exponent n. When n is a positive integer, exponentiation corresponds to repeated multiplication of the base: that is, bn is the product of multiplying n bases: b n = b × ⋯ × b ⏟ n ...

Eric Tressler

and @LeakyNun conventions don't have names. It's the convention that 0^0 is taken to be 1? I'm a mathematician

Leaky Nun

@EricTressler I thought it's the convention to leave 0^0 as undefined...

flawr

@EricTressler What field are you working in?

Eric Tressler

12:42 PM

Combinatorics. @LeakyNun If you're doing integrals or probability, and 0^0 shows up, it's going to be in the context of a parametrized function

and you will almost certainly be trying to integrate across that point

Leaky Nun

@EricTressler I see

flawr

@mınxomaτ What proof?

mınxomaτ

@flawr Click the button where it says "Read the proof"...

Eric Tressler

Anyway, there are some impassioned arguments for just taking it to be 1. It doesn't matter to me, because I mostly deal with discrete things

The main one is to make the binomial theorem work in all cases

flawr

@mınxomaτ A ton of equations, but no text/explanation?

Eric Tressler

12:45 PM

Try expanding (x + 0)^n by the binomial theorem

mınxomaτ

@flawr Try actually reading.

Chapter 2, Claim 1 is the basis for formulas constructed by the Formula Compiler.

> This follows from the fact 0^0 = 1 while 0^n = 0 for any n > 0. Readers
who would prefer not to use this fact (which might feel rather like cheating) are
invited to replace the definition of δ using any of a number of formulas listed
for sequence A000007 at the OEIS [3].

Eric Tressler

@LeakyNun The only term that doesn't die is (x choose 0)x^n0^0 = x^n * 0^0

flawr

@mınxomaτ Oh I got the wrong link, my browser seems to have trouble downloading that pdf

Eric Tressler

@LeakyNun So unless you want to put the condition on the binomial theorem that neither a nor b in (a + b)^n is 0, it's more convenient to take it to be 1

Leaky Nun

@EricTressler alright.

flawr

12:55 PM

@mınxomaτ I cannot open that pdf, do you have a mirror?

mınxomaτ

That is the mirror :D

Try wget-ing it.

flawr

Well where can i find the original?

mınxomaτ

That's no longer available.

flawr

@mınxomaτ It seems that this is a linux thing, I'm on windows=/

mınxomaτ

But it definitely works. So ... get a better browser.

El'endia Starman

12:58 PM

@flawr I don't know/remember what those are. Explain, please? :)

flawr

@mınxomaτ Thank you

Ok, given a BASIC program, thsi compiler writes a mathematical function for it. However I do not really see the point, those functions it does return seem way too complicated?

Is it some kind of obfuscation?

mınxomaτ

@flawr github.com/minxomat/FormulaCompiler

flawr

> involving only basic arithmetic and summation notation

now I understand=)

That does indeed make a lot of sense=)

(that sentence should perhaps be included in the main website=)

mınxomaτ

@flawr It is!

It's the first sentence on the whole site :D

flawr

I just browsed your github site

"code size enthusiast" -> "code-golf nerd"

XD

Sp3000

1:25 PM

Not sure if this has been posted yet, but anyone feel like some XSS golf? escape.alf.nu

zʏᴀʙiɴ101

Solved level zero in 20 chars!

Sp3000

I believe 12 is possible (no cheating by looking at the scoreboards btw, cos people accidentally put their XSS as their username)

zʏᴀʙiɴ101

I realized about the function eval(), which can alert(1) in 20 chars.

However, level one... well, nope.

They sanitise double quotes o_o

aditsu

I got 13 chars

zʏᴀʙiɴ101

@aditsu For level zero?

aditsu

1:31 PM

yeah

zʏᴀʙiɴ101

Welp, I got... 20 chars.

The "+ disarm is not so golfy.

aditsu

ah, 12

zʏᴀʙiɴ101

O_O

aditsu

thanks to a horrible js feature :)

Sp3000

:P

zʏᴀʙiɴ101

1:34 PM

zyabin101@avista MINGW32 ~/Desktop/ws1a00/ws1a00
$ diff /dev/null README.md
0a1,3
> # README
>
> This is the index repo for ws1a00.

I didn't expect that diff format.

I expected something like that:

@@@ (whatever means 0a1,3 in the git-like diff format) @@@
+# README
+
+This is the index repo for ws1a00.

Sp3000

Hmm 14 for level 1

zʏᴀʙiɴ101

Hmm I can't solve it, and I can't ask for hints for level one

Eric Tressler

regex golf was fun

zʏᴀʙiɴ101

The --git option for diff probably won't work, as it might involve some weird mechanics that check for execution outside of git, parameters other than a/... and b/... and other things.

Eric Tressler

not sure I'm interested in XSS golf. it has a lot more garbage at the bottom of the screen (not as clean as regex golf)

aditsu

1:41 PM

yep, 14 :)

zʏᴀʙiɴ101

I didn't check the diffutils code, so I don't exactly know.

Sp3000

The "garbage" is the messy scoreboard, unfortunately :/ it's also spoilery, so it's a bit annoying

zʏᴀʙiɴ101

... The -c option seems to work. :)

Eric Tressler

@Sp3000 Yeah, I saw that. It's the same domain as regex golf, so I assume it's by the same person? It's a weird design decision for a puzzle

Sp3000

That was my assumption too, so yeah it's a bit weird...

Personally I find the puzzles interesting enough and I just ignore the scoreboard anyway, so I'm not too bothered

New Main Posts

1:46 PM

0

Q: Teach GabeN the number 3 using code Golf!

GabeN is the CEO of Valve. He wants to make Half life 3, But he can't. He just can't count to 3.Now You will attempt to teach him the number 3, by doing Code Golf! What you should do: Input a list of integers between -10000 to 10000. if you can make 3 using all the numbers in the list and th...

code-golf arithmetic restricted-source

New Sandboxed Posts

2:06 PM

0

A: Sandbox for Proposed Challenges

GabeN is the CEO of Valve. He wants to make Half life 3, But he can't. He just can't count to 3.Now You will attempt to teach him the number 3, by doing Code Golf! What you should do: Input a list of integers between -10000 to 10000. if you can make 3 using all the numbers in the list and th...

aditsu

2:28 PM

lulz ^

Eric Tressler

@aditsu I thought it was going to be the subset sum problem in disguise, but it's much less interesting

aditsu

oh I didn't read it

aditsu

2:43 PM

@flawr I like that the numbers kinda stay in the same place relative to each other, compared to the original notation

Code Golfer's Corner

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