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Anonymous
7:00 PM
@J.Salle DST ends in about a month. DST (and the UK equivalent, BST) is for summer.
 
Anonymous
@Neil But that's not HTML.
 
@Mego Well technically no one's ever needed to deal with it because who the hell cares about IE amirite?
 
Anonymous
@J.Salle Back when IE7 was popular, it was very much needed.
 
@Mego I meant 'here' as in where I live hahahah
 
@Mego But it is part of an HTML document
 
Anonymous
7:01 PM
You joke, but there was a time when IE was the most popular browser.
 
"popular"
 
Anonymous
@Neil Sure, but so is JS within <script></script> tags. That doesn't make it HTML.
 
oh well, gtg guys, have a nice afternoon/evening/morning everyone o/
 
Anonymous
@Neil In 2008, IE7 had a roughly 60% usage share according to W3Counter stats. That's popular.
 
\o @J.Salle
 
7:05 PM
@Mego Actually I thought they made it ... /> (with space) valid in HTML5, rather than being an ignored invalid attribute in earlier browsers
@Mego usage != popularity
people used it because they didn't realise that it sucked
 
should I leave codegolf.stackexchange.com/questions/143772/… a while before accepting an answer?
I can never remember the etiquette
 
@Lembik Don't accept answers.
 
Jul 3 at 14:25, by betseg
https://upload.wikimedia.org/wikipedia/commons/a/af/Turkey_map_with_30._%26_45._‌​meridians.png 30° is UTC+2 and 45° is UTC+3. We were using UTC+2 with DST, now it's UTC+3 all year. wtf
 
@cairdcoinheringaahing go on...
 
we're back to normal time + DST now ^^
erdogan stahp
 
7:07 PM
Hehe. Neutral cube.
  _____
 /\    \
/.\\.__.\
\ ./    /
 \/____/
 
@Lembik Hold, on. Checking meta
 
@betseg rip programmers who'll have to deal with this
 
@cairdcoinheringaahing ok
 
Has there been a challenge about drawing ascii art cubes like that? (without faces)
 
@Mego makes it easier to parse
 
7:07 PM
@HelkaHomba Yep, tonnes
 
Like here is 1x2x3. I've seen some but not exactly like this I think.
 
Also, why are you thinking about simple cube drawing? You are the challenge master! You singlehandedly created a new challenge type :P
 
 ____
/\   \
\ \___\
 \/___/
 
-3
Q: link list, stack to reverse the characters

momoDesign and implement an application that reads a sentence (at least 4 words) from the user and store them in a link list, and then prints the sentence with the characters of each word backwards. Use a stack to reverse the characters of each word.(using java)

 
Anonymous
@Neil People were well aware that it sucked. There just weren't other options that didn't also suck, and it was bundled with Windows (which had somewhere around 80% usage).
 
7:08 PM
@NewMainPosts ಠ_ಠ DJ ninja'd my VTC :(
I never thought I'd say that
 
@cairdcoinheringaahing I've done plenty of plain ol ASCII art challenges
 
29
A: We're not a Q&A site. But what should be done about it?

Martin EnderRemove the Accept feature This feature is likely way too integral to how SE instances work for this to be possible without forking the software, but I don't think the concept of accepted answers is useful on PPCG. The most fundamental pillar of this community is that every single question needs...

 
@DJMcMayhem I basically solved it, but the code was too horrible to post.
 
No such thing :P
 
@Adám He says, while being an active user on a code golf site
 
7:12 PM
@DJMcMayhem The edge cases killed it.
 
:/ I was worried about that
 
@cairdcoinheringaahing I'm going to include it. I don't care if the community wants to remove it afterwards: they can do so.
I hope someone will read it to the end
 
@LeakyNun Just for that, I will read the full background :P
 
@cairdcoinheringaahing thanks :P
 
CMC: Given a binary number ending in 0, express it in decimal with only 2, +, and * with fewest 2's. e.g. 11010 -> 2*2*2*2+2*2*2+2
 
7:18 PM
@Mego So Firefox 2 sucked? (It came out the same month as IE7)
 
I hope you can understand... @cairdcoinheringaahing
 
Ugh, why is review always empty when I check it? D:
 
@HelkaHomba Are you sure you mean * and not multiplication?
 
@LeakyNun Well, it'd be a good way to exercise my brain, knowing the challenges you tend to set :P
@Adám * is multiplication
 
@cairdcoinheringaahing Not in APL.
 
7:19 PM
@Adám Did I really make a mistake or is this an APL joke?
ah :p
 
@Adám Same in Jelly, but in most languages it is
 
@HelkaHomba So much more interesting if each language can only use those three characters!
 
@Adám No it wouldn't. Brainfuck would be <pause for comedic effect> fu*ked
 
Anonymous
@HelkaHomba Actually, 17 bytes: R;r'2*@░⌠'*j⌡M'+j
 
@cairdcoinheringaahing Yeah, that's no-Brainer.
 
7:21 PM
@Adám nice one :P
 
@Mego Nice penguin shades
 
Anonymous
Blame DJ and my incessant puns :P
 
Oooh, what would Helka look like with shades on his?
 
ehh
 
@Mego Nice shades penguin
 
7:23 PM
@HelkaHomba JavaScript (ES6), 45 bytes: f=(n,s=2)=>n<4?s:f(n/2,s+'*2')+(n&2?'+'+s:'')
 
Hehe, I just watched one of @Helka 's Minecraft videos. You sound so different to what I thought you'd sound like
 
@HelkaHomba V, 35 bytes: Try it online!
Probably terrible
 
Anonymous
16 bytes: ;r'2*@░⌠'*j⌡M'+j (little-endian bit order for input)
 
@Adám Everything is APL if you want to get technical
3
 
ಠ_ಠ You include mathematical CMC's in your videos? @HelkaHomba
 
7:25 PM
Of course!
 
@HelkaHomba I don't know if that's good or bad :P
 
How could that possibly be bad?
 
Also, judging from your sorting system, you spend wayyyy too much time on Minecraft :P
Q: Do questions have to ask the answerers to write code to answer them?
 
@HelkaHomba SOGL, 13 bytes: {ēA?⁽aΖ2*Οļ+p - little-endian bit order. Also assumes that monadic + is allowed :p
 
@cairdcoinheringaahing done
 
7:40 PM
@cairdcoinheringaahing not necessarily
 
0
Q: Cyclotomic polynomial

Leaky NunBackground (skip to definitions) Euler proved a beautiful theorem about the complex numbers: eix = cos(x) + i sin(x). This makes de Moivre's theorem easy to prove: (eix)n = ei(nx) (cos(x) + i sin(x))n = cos(nx) + i sin(nx) We can plot complex numbers using the two-dimensional Euclidean plane...

 
@NewMainPosts Wow that was fast
@NewMainPosts This is one of the times is which MathJax would be greatly appreciated :P
 
@cairdcoinheringaahing would it make a difference?
 
@LeakyNun Yeah, the plain text can be a little difficult to distinguish from the maths, but it's still clear
 
@cairdcoinheringaahing Does PPCG have mathjax enabled finally?
 
7:44 PM
@HelkaHomba No, it got rejected on meta IIRC
 
omg someone really read it @cairdcoinheringaahing
z<sup>n</sup> = re<sup>inθ</sup> should be z<sup>n</sup> = r<sup>n</sup>e<sup>inθ</sup> — H.PWiz 1 min ago
 
@LeakyNun I'm reading it (well, struggling to understand it). Seems interesting. Way to complicated for me, but interesting nonetheless
 
8:06 PM
0
A: Sandbox for Proposed Challenges

caird coinheringaahingChange the rules of Life Life-like cellular automaton are cellular automaton that are similar to Conway's Game of Life, in that they operate on a (theoretically) infinitely large square grid, where each cell has exactly 8 neighbours, and is one of 2 states, namely alive and dead. However, these...

 
8:26 PM
dances, on the graves of his frenemies
I think Empyrion is better than minecraft.
Any fans?
Made this the other day, super fun to just see a picture and do a build: https://steamcommunity.com/sharedfiles/filedetails/?id=1134084490
It's like dang legos.
 
never heard of empyrion
 
CMC: Given N return an (N+1)×N boolean matrix where the first row is all true, and the last is all false and each row has one more true than its predecessor in a pseudo-random position.
 
slinks back, deep, deeeeep, into the shadows
 
@Adám the first row is all false and the last is all true? or else one fewer false.
 
@Giuseppe (N+1)×N so that the last can be all true
 
8:40 PM
Jelly, 11 bytes:
¬TXṬo
0ẋÇÐĿ
¬TXṬo  Helper Link; add another 1 somewhere pseudorandom
¬      Vectorizing Logical NOT; 0s become 1s and vice versa
 T     Get indices of truthy values (formerly 0s)
  X    Pick a random index
   Ṭ   Make a list with a 1 at that index
    o  Vectorizing Logical OR them together to put the 1 back in the list
0ẋÇÐĿ  Main Link
 ẋ     Repeat   by the argument
0             0
   ÐĿ  While the results are unique (that is, while they're not all truthy)
  Ç    Place a random 1
@Mego are those sunglasses to help you keep cool in that hot weather over there?
:P
hi can I have ideas for a name for my new programming language? I've decided that its syntax will kind of resemble APL's a bit in that functions are pre/in fix and operators are postfix, and I'll have brackets like [...] for a nilad, (...) for a monad, and {...} for a dyad (essentially link separators but easier to use)
also it focuses on numbers and lists but does have a few string functions too
 
@HyperNeutrino was that really necessary?
 
ok maybe not for cmcs
 
@LeakyNun Definitely on-topic.
@HyperNeutrino "Braces"
 
@Adám did I say it isn't?
 
@LeakyNun Did I say you said it wasn't?
 
8:53 PM
@Adám I feel like braces would be a better name for a language with a ton of braces; programs in my language will not have that many braces
 
@Adám did I say you said I said it wasn't?
 
@HyperNeutrino You have to tell us a bit more. Do you also use parens for order of execution, or go Jelly style?
 
@Adám Jelly, 10 bytes: Ẋ0;ṬƤz0ZṚG
 
@HyperNeutrino How will you encapsulate operators?
 
8:55 PM
parens will obey order of execution; that is, the contents of a bracketed expression are considered a single function
@Adám what do you mean by that?
@LeakyNun Is the G necessary?
 
@HyperNeutrino for beautiful purposes
 
ah ok :P
(you beat me anyway so you can afford to prettify :P)
 
@HyperNeutrino Dyalog uses curly braces for both monadic and dyadic functions, and also for monadic and dyadic operators. Operators are disambiguated by the presence of ⍺⍺ and optionally ⍵⍵.
 
can you give an example?
 
@LeakyNun I couldn't believe taht we haven't already had the cylcotomic polynomial challenge:)
 
8:58 PM
7 hours ago, by Leaky Nun
I'm surprised we haven't had a question on cyclotomic polynomials
 
@HyperNeutrino {…} ambivalent fn {…⍺⍺…} monadic operator {…⍵⍵…} dyadic operator.  can be zero or more of any chars.
 
wait you can make custom operators in APL?
 
@HyperNeutrino Sure! Oh, you didn't know?
 
wait no I remember seeing you use this once in the APL room I think
 
@flawr you should do a vanilla version :)
[I feel like definition 3 is the easiest]
 
9:00 PM
@HyperNeutrino You just cannot make them tacit (as there would be no way to represent the operands).
 
ah ok
so like can you give me an example of where you'd use it? I think I know what I'm planning on doing in place of that but I'm not sure yet
they should add a keyboard shortcut to swap the clipboard contents with the highlighted text
 
@Adám Is the term n-adic for describing the number of arguments coming from APL? I think in all other languages I've come across this it was called n-ary.
 
Ans→X
DelVar [A]
{1,X→dim([A]
For(A,1,X
randIntNoRep(A,A-X+1→L1
List►matr(seq(L1(Z)>0,Z,1,X),[B]
augment([B],[A]\textsuperscript{T})\textsuperscript{T}→[A]
End
TI-BASIC
74 bytes
 
@LeakyNun What do you mean?
 
@flawr Yes, I think so. n-ary is ambigous with the base of a number system.
 
9:02 PM
@Adám monadic also has different notions!
that is why I'm asking=)
 
@flawr Really?
Monadic may refer to: In logic and mathematics, a predicate, a relation or a function having an arity of one is called monadic In category theory, an adjunction is called monadic if and only if it is equivalent to the adjunction given by the Eilenberg–Moore algebras of its associated monad In chemistry, monadic is a synonym for univalent == See also == All pages with a title containing Monadic Monad (disambiguation)...
 
Yes, e.g. regarding monads in haskell.
 
@flawr monad ≠ monadic
APLers only use the term monadic function, not monad.
 
But in haskell you do talk about monadic values
 
@flawr without libraries
 
9:04 PM
And monadic functions. (functions on monadic types)
 
@flawr monadic functions
 
@LeakyNun that could get even longer, as I do need isPrime and polynomial division
 
2
A: Base Conversion With Strings

VenAPL, 10 bytes {⍺⍺[⍵⍵⍳⍵]} This is an APL operator. In APL, ⍵ and ⍺ are used to pass values, while ⍵⍵ and ⍺⍺ are usually used to pass functions. I'm abusing this here to have 3 arguments. ⍺⍺ is the left argument, ⍵⍵ is the "inner" right argument, and ⍵ is the "outer" right argument. Basically: ...

 
@Adám I was about to add that functions and values are more or less the same in haskell
so it just confuses me when I hear people talking about monadic something as I just know Haskell but no APL (yet :)
(just googled, apparently monadic function is also used, e.g. for functions that return monads)
 
5
A: Math in manhattan

AdámDyalog APL, 104 81 79 93 75 bytes Edit: Now handles 4342343 -M 34 → 43423 correctly. M←{⍎(5|⌊⍺⍺2)⊃'⍺×M⍣(⍺≠1)⍎⊃b'(b⎕R(⍵⍴'&')⊢a)'10⊥⍺⍵'(('(.*)',b←⍕⍵)⎕R'\1'⊢a←⍕⍺)} Background This extends APL to include the Manhattan operator. An operator in APL terminology is a modifier of functions (e.g. ÷). ...

@flawr Not too late to learn APL!
 
9:07 PM
@flawr I don't think you need any prime checking
but it doesn't matter if it becomes longer
I always consider it an achievement to not use libraries
 
6
A: Create a simple 2048 game clone

AdámAPL (Dyalog APL), 153 150 167 bytes U←{⍵⍵⍣¯1⍺⍺⍵⍵⍵} c←⎕UCS 'you ',{2048∊⍵:'win' (z/∊n)[?+/z←0=∊n←⍵]←2 ⎕←4↑¨⍕¨n 1∊(⍉2=⌿n),(2=/n),0=n:∇{⍵≡r←{4↑c(c¨2/¨t)⎕R(c¨,¨2×t←2*⍳11)c⍵~0}¨U↓U(⍉∘⌽⍣⎕)⍵:∇⍵⋄r}n 'lose'}4 4⍴0 Prompts for move; 0=Left, 1=Up 2=Right, 3=Down Try it online! Ungolfed, with whitespac...

 
@LeakyNun why not? I think I have to have the base cases!
 
@flawr you don't need primes to factorize a number
 
@HyperNeutrino Notice the U←{⍵⍵⍣¯1⍺⍺⍵⍵⍵} in 2048.
 
as prime powers
 
9:09 PM
ok I am very much so confused now D: rip
 
you can just take the LCM of the cyclotomic polynomials of the prime power factors, which does not require primality check @flawr
 
@HyperNeutrino What confuses you? (Shall we take this in the APL room?)
 
@LeakyNun I think the polynomial LCM would even take a lot more to implement than primality checking, wouldn't it?
 
@Adám sure
 
@flawr how would you do it with prime checking then?
just use mobius function lol
formula given in mathworld
 
9:11 PM
@LeakyNun and how do you do that without any prime factorization?
 
@flawr when did I say I won't use prime factorization?
 
I don't think you did, but I said this is gonna make my code a lot longer:)
 
then just submit it as another answer
 
Lets try but perhaps tomorrow (it is getting late for me right now=)
 
0
A: Sandbox for Proposed Challenges

Ian H.Life and Death of Trees code-golf polyglot ascii-art The Challenge Write a program that takes an integer N as input, and outputs the stage of life or death that a tree is currently in. N will always be between 0 and 10. The Stages of Life and Death Life: To draw a stage of life, simply draw...

 
9:16 PM
The answer I have now is based on a piece of code I wrote a while ago, but this was optimized for exactness and efficiency, and I think I can sacrifice efficiency.
 
9:28 PM
does 05AB1E have cumulative sum function?
 
@Neil No, but ηO works (prefixes, sum)
 
@flawr talk about being longer without library
 
@Emigna thanks, I'd found .pO but I didn't realise there was a byte to be saved
 
Yeah, prefixes is useful so often so it deserved to be a 1-byter when more bytes were made available due to the custom code page
 
Australian Research and Space Exploration
Or ARSE, for short.
 
9:35 PM
@LeakyNun I need to implement polynomial multiplication, which needs about 50 chars.
 
2
A: Cyclotomic polynomial

xnorHaskell, 128 bytes (h:t)%q|all(==0)t=[]|1>0=h:zipWith(\x y->x-h*y)t q%q f n=foldl(%)(1:(0<$[2..n])++[-1])[tail$f k++repeat 0|k<-[1..n-1],mod n k<1] Try it online! No imports.

 
WTF
oh it is @xnor
No chance against haskell gods
 
@flawr how does that solution work?
(I can't read haskell)
 
@LeakyNun still trying to figure that out=)
 
@Pavel ARSE launches rockets?
7
 
9:40 PM
Any Beach Boys fan here?
i wish this video never ended https://t.co/6J3U0zLccd
 
@LuisMendo do my challenge in matl :P
 
@Emigna do you know how to prepend a zero to a list in 05AB1E?
 
@LeakyNun Uh, the definitions were too long and I gave up :-) I may give it another try
 
@LuisMendo the definitions were too long?
they are nothing compared to the background
 
@Neil 0¸ì should do the trick
 
10:11 PM
@LeakyNun I had a 34-byte solution that doesn't work past input 5 due to floating point errors :-(
 
@LuisMendo lol
 
It was so nice, deconvolution and all :-)
 
@LuisMendo Don't worry, I heard it :)
 
:-D
 
-1
Q: Build a checkerboard

JustinEnter the x and y (comma seperated) for every square (indexed 0-7) on a checkerboard, followed by a "r" or "b" (for red or black) where the top of the board (closer to y=0) is red and the bottom is black. newlines between squares and no spaces. Desired output: 0,0r 0,2r 0,4r 0,6r 1,1r 1,3r 1,5r...

 
10:25 PM
the weather here is great
it's 10 degrees cooler than yesterday
 
@LeakyNun Is it ok if it only works up to input 20 or so, due to floating point errors? What's the requirement for maximum input that should be supported?
 
10:36 PM
0
Q: One More Program and I'm Out!

fireflame241Given a positive integer nesting level n and string s of printable ascii characters( to ~, output a program which, when run in the same language, outputs a program which outputs a program . . . which outputs the string s. A total of n programs should be generated, all of which should be run in t...

 
10:49 PM
@NewMainPosts uneval builtin in Jelly lolololol
 
@LuisMendo reasonable...
I trust your judgment
 
@HyperNeutrino Trust Jelly to make a decent challenge super easy :P Bot as bad as the Mathematica built in for Leaky's question though :P
 
yeah :P
 
@LeakyNun No floating-point errors anymore, and down to 32 bytes. It turned out to be much easier than I thought :-)
 
there I made a less cheaty answer :D
I find it interesting that leaving a chat room from one computer causes all other computers with that chat room open to navigate to the SE chat homepage
 
11:05 PM
@HyperNeutrino That is pretty cool. APL should have that as a built-in too; ⍎⍣¯1.
 
wait you can invert functions by applying them -1 times? :o
 
@HyperNeutrino Sure! Oh, you didn't know?
 
Nope! I never thought that it would let you do that! :D
 
@HyperNeutrino But not all functions are invertible. is not :-(
 
ah ok :(
what if you raise a function to the power of a decimal number?
 
11:08 PM
@HyperNeutrino Won't work. Has to be to the power of an integer or a function.
 
ah ok
wait what does raising a function to the power of a function mean?
 
@HyperNeutrino apl might not have it
but fractional application is a thing in math
 
huh interesting
 
@HyperNeutrino f⍣g means f⍣n where n is a non-negative integer so that f⍣n g f⍣(n-1)
 
huh where did n come from?
 
11:10 PM
@HyperNeutrino APL found an appropriate n for you.
 
ah ok
interesting
 
@HyperNeutrino The most common gs are = and which calculate the fix-point or limit of applying f.
 
In mathematics, an iterated function is a function X → X (that is, a function from some set X to itself) which is obtained by composing another function f : X → X with itself a certain number of times. The process of repeatedly applying the same function is called iteration. In this process, starting from some initial number, the result of applying a given function is fed again in the function as input, and this process is repeated. Iterated functions are objects of study in computer science, fractals, dynamical systems, mathematics and renormalization group physics. == Definition == The formal...
 
@HyperNeutrino E.g. Phi (the golden ratio) is 1+÷1+÷1+÷…1+÷2 which can be written as (1+÷)⍣=2
 
11:14 PM
oh huh interesting!
 
@HyperNeutrino Here is an example of using a user defined function as right operand to :
0
A: 196 algorithm code golf.

AdámDyalog APL, 17 bytes {⍵+⍎⌽⍕⍵}⍣{⍺≡⍎⌽⍕⍺} {⍵+⍎⌽⍕⍵} add argument and its reverse... ⍣ ... until... {⍺≡⍎⌽⍕⍺} ... the result is a palindrome.

Actually, now that I see that, I should probably flesh out the explanation a bit.
 
oh wait f power g just applies f until g
 
@HyperNeutrino Until a g b where a and b are successive results.
 
ah ok
 
i.e. a≡f b
 
11:23 PM
The naïve LCM solution has a time complexity of $O(a×b)$, but is there a more efficient algorithm?
 
@Maltysen I like iteration...
 
@ATaco -1 for mathjax.
 
@Adám 05AB1E, 14 bytes: L<.roηOb0¸ì0ζζ
 
@Adám That didn't answer the question :P
 
11:25 PM
Ah, the fine art of combining strange Unicode chars and markup to form beautiful mathematical formulas…
 
Say, so I want to add a YouTube channel to the feeds of a chatroom. How do I do that?
 
calculate GCD using euclid's algorithm and then do a*b/gcd(a,b)
@SimplyBeautifulArt if YouTube has RSS feeds you can just open the feed and paste the feed link into the "manage feeds add feed" thingy
 
Neat
 
@HyperNeutrino where is the RSS feeds thing I'm looking for?
 
idk, I can't find the RSS for youtube
 
11:29 PM
@ATaco naive?
oh wait ninja'd by like forever
 
@Maltysen iterate through all numbers until you find something divisible by a and b
 
for(int i=1;i<=a*b;i++){
	if(i%a == 0 && i%b == 0){
		return i;
	}
}
hat's the Naïve solution.
 
yeah I was gonna suggest euclidean algorithm
 
0
A: Sandbox for Proposed Challenges

Digital Traumacode-golf geometry Like a path-segment; touched for the very first time Given an ordered list of 2 or more 2D cartesian points, output a truthy value if the path touches itself or self-intersects, or a falsy value if it does not touch itself or self-intersect. You may assume that consecutive p...

 
Ooooh, O(log n) complexity~
 
11:34 PM
How do I get someone's YouTube channel ID...
Never mind
 
ooh kurzgesagt
 
Yeah! In a nutshell!
 
If there is a non-recursive solution to a problem, should one take it to avoid overflowing the call stack, or take the recursive solution because it's cleaner, and (in this particular hypothetical case) easier to understand?
 
for gcd?
 
11:42 PM
Yeah
My solutions are:
int gcd(int a, int b){
	if(a == 0)
		return b;
	if(b == 0)
		return a;
	return gcd(b,a%b);
}
int gcd_alt(int a, int b){
	int c;
	if(a == 0)
		return b;
	while(b != 0){
		c = b;
		b = a%b;
		a = c;
	}
	return a;
}
 
I'd use the alt one because it won't die
 
If anyone wants to add kurzgesagt (In a nutshell) to their chat's feeds, use the following link: youtube.com/feeds/…
 
I'd use the iterative solution
 
@Adám Augmented Reality.SE?
:O is there really no AR.SE
an SE for VS/AR should be proposed
 
VR/AR existed.
But it died.
It had enough supporters, but not enough valid questions.
 
11:56 PM
RIP ARSE
16
 
@Downgoat out of context quote of the day
 

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