The Nineteenth Byte

Григорий Перельман

12:00 AM

The sign-in page is HTTPS, but the main page is showing up as HTTP for me

Helka Homba

@ГригорийПерельман When I type bing.com into Edge it does indeed go to http ._.

Riker

CNN isn't https

Григорий Перельман

I'm using Chrome though

Riker

neither is BBC

Григорий Перельман

For all the hate Bing gets, it's still probably more common than CNN.

(If only because it's default on so many systems)

Riker

12:03 AM

@HelkaHomba Baidu is #4 on Alexa's top 500 sites, it doesn't use HTTPS.

Helka Homba

@ГригорийПерельман For bing, Chrome forces me to use https but in Edge I can choose either one

Riker

the top three are Google, Youtube, and Facebook respectively, which all use HTTPS

Григорий Перельман

@Riker What's Baidu?

Riker

chinese clone of google

Григорий Перельман

Ah

Riker

12:04 AM

Baidu

Baidu, Inc. (Chinese: 百度; pinyin: Bǎidù, anglicized /ˈbaɪduː/ "BY-doo"), incorporated on January 18, 2000, is a Chinese-American web services company headquartered at the Baidu Campus in Beijing's Haidian District. It is one of the largest Internet companies in the world. Baidu offers many services, including a Chinese search engine for websites, audio files and images. Baidu offers 57 search and community services including Baidu Baike (an online, collaboratively built encyclopedia) and a searchable, keyword-based discussion forum. Baidu was established in 2000 by Robin Li and Eric Xu. Both of...

I think tha'ts the winner

Helka Homba

Baidu is https for me, but I realize it's probly cause I use the HTTPS everywhere chrome extension

Riker

lol

qq.com also has http, #8 on alexa

Григорий Перельман

@HelkaHomba That would explain it, yes.

Helka Homba

(it doesn't mean literally everywhere, just where possible (I think?) e.g. meta.codegolf.stackexchange.com is still http)

Григорий Перельман

'ey, I just got my silverlight dependency in by installing $\LaTeX$!

ATaco

12:08 AM

The literal text $\LaTex$ and the compiled $\LaTeX$ look identical to me now.

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

List All the Related Chat Systems Yet another XKCD-inspired challenge... Task Write a function or program which takes as an argument one of the names of the chat systems in the comic above. Output will be a comma-delimited list of all chat systems that intersect it. Input and output must be ...

Down Christopher

Hallo

Need to finish a challange

Thomas Ward

sigh

Anonymous

→ 5 messages moved to Trash

Riker

→ 5 messages moved to Trash

Mendeleev

12:14 AM

OPPCGMCS is shutting down on the 27th.

Anonymous

Why is it that it's always the same users whose messages I have to move to Trash...

Riker

@Mendeleev anybody who's active on the server has already been pinged

Thomas Ward

@Mego I'm more curious why you haven't poked anyone about this.

Mendeleev

→ 5 messages moved to Trash

Riker

@ThomasWard about what? the noisy messages?

Thomas Ward

12:15 AM

o/ @Randal'Thor

ATaco

On a less noisy note, I plan to write a Tac-it Language, entirely so I can call it "TacO"

Down Christopher

Yes

Anonymous

@ThomasWard People have been poked.

mınxomaτ

Because we don't really want to have a permanently updating shamelist? We know how the users are and have increases presence for that reason.

Григорий Перельман

@Mendeleev What's that?

Riker

12:16 AM

open ppcg minecraft server

Anonymous

@mınxomaτ I think he meant moderators who can take more lasting action against frequent troublemakers. Like I said, they have been poked.

Rand al'Thor

@ThomasWard Don't mind me; I'm only here because flags.

Thomas Ward

Same. :P

@Dennis I poke thee and drag you elsewhere

Mendeleev

Why was I kicked?

ATaco

We were being a bit Noisy, I believe Mego dealt with it.

DJMcMayhem

12:17 AM

diamond invasion

Down Christopher

@Mendeleev Noise messages at least afaik

Mendeleev

@DownChristopher example?

Anonymous

@Mendeleev If you get kicked, "y kik :(" is probably not the best message to send upon returning. That's just inviting more kicks for deliberate misspelling and obscuring messages.

Григорий Перельман

That is not a good reason to kick someone from TNB

6

Mendeleev

At least the gaotspek isn't back

Riker

12:19 AM

@ГригорийПерельман what isn't? I'm confused here

Anonymous

@Mendeleev Please don't bring it back.

Riker

oh, for mispelling? yeah

Mendeleev

@Mego Wasn't going to

> mispelling

Riker

yah

Григорий Перельман

gaotspek? Is that like juic avocad?

DJMcMayhem

12:20 AM

@ГригорийПерельман What isn't a good reason? "y Kik"?

Григорий Перельман

Yes

Riker

I think kicking for deliberate misspelling

Dennis

5 mins ago, by Mendeleev

→ 5 messages moved to Trash

DJMcMayhem

@ГригорийПерельман That was not the reason for the kick

Григорий Перельман

Oh, it was a bit confusing.

Mendeleev

12:21 AM

@Dennis I don't htink that was a good kick reason either

Григорий Перельман

@Dennis ¯\_(ツ)_/¯ don't think that's a good kick reason either.

Mendeleev

@Downgoat please add me to beta testing for app

Downgoat

@Mendeleev you used to be Dmitry, right?

Riker

and wat and tomato iirc

Mendeleev

@Downgoat Yes. Also wat.

Downgoat

12:22 AM

Ok, yeah, I added you

Mendeleev

And tomato.

aight how do i get it?

Dennis

@Mendeleev @Pavel A combination of chat moderators and room owners was dealing with noise. Bad moment to add even more noise to the chat room.

4

Mendeleev

@Dennis Sorry

Downgoat

It'll take some time for Apple to process/review it, once that happens you'll receive an email with instructions

Mendeleev

ok

fəˈnɛtɪk

12:23 AM

Lets not argue about kicks.

2

Down Christopher

I was removing the message and hit enter on accident

Григорий Перельман

Lets not argue.

Discuss golf instead

mınxomaτ

Returning from a kick is most definitely not the time to argue about it. Asking for clarification is OK, but kicks are issued for a reason. It's your time to reflect and improve.

Dennis

Chat messages are deleted or trashed and users are kicked or suspended to keep the room on topic. Lengthy arguments after said actions achieve the opposite goal. If you disagree with chat moderation, take it to meta.

24

Pinning since this has been an issue at least twice today.

Григорий Перельман

CMC: given a string of printable ascii, randomize case of each letter, without affecting other symbols.

Downgoat

12:27 AM

Question: On cheddar, if I added a feature X, before challenge Y was created, feature X's commit has a timestamp. If I push that commit after challenge Y was created, is my answer non-competing?

Dennis

Yes. The interpreter has to be published, not sit on your hard drive.

Anonymous

@Downgoat It is only allowed if the interpreter/compiler/whatever with the feature was publicly available prior to the publishing of the challenge (in the sandbox or on main).

ATaco

@ГригорийПерельман I haven't given RProgN2 a Rand function yet :(

Anonymous

I would also add chat messages, comments, and other posts to that list of sources - if someone on PPCG says "I'm thinking about making a challenge about X", and someone else adds a feature to a language which trivializes X, it's pretty blatant that they're trying to use prior knowledge about the challenge to gain an advantage.

Down Christopher

@Mego That has been mentioned before

Downgoat

12:30 AM

@ГригорийПерельман Cheddar: @.chars.map(i->i.test(/[a-z]/i)&&Math.rand(2)?i.upper:i.lower).fuse

Anonymous

@DownChristopher It has, but I'm not sure if it was ever brought up and voted on in a meta post. I know I've said that it's my view in the past.

Григорий Перельман

@Mego Non-issue IMO. No one does that, ever. Not worth making a meta post.

@Downgoat What's @?

Downgoat

@ГригорийПерельман @.property essentially creates a function. It's the same as doing foo -> foo.property

example: ["HI", "HELLO"].map(@.lower) results in ["hi", "hello"]

Григорий Перельман

I see.

Down Christopher

Anyone want to debug my code? All 27 lines

Григорий Перельман

12:32 AM

Do you need the regex test? Shouldn't upper/lower just not affect other chars

Helka Homba

Which will happen first: [1] All websites will be https (or at least have the option) [2] All flagship smartphones will have no ports (no charging, no headphone), everything is wireless

Mendeleev

@HelkaHomba Second one.

Down Christopher

@HelkaHomba The 2nd one for apple

Downgoat

@HelkaHomba #2

Anonymous

@ГригорийПерельман Actually, 10 bytes: ⌠`Ö2J*ƒ⌡MΣ (disable output cache because randomness)

Helka Homba

12:33 AM

@DownChristopher But even Samsung etc?

Downgoat

@ГригорийПерельман >_> shit yes, that is true

Григорий Перельман

@Mego Output cache disable is saved in the permalink

Downgoat

Golfed to 49 bytes: @.chars.map(i->Math.rand(2)?i.upper:i.lower).fuse

Anonymous

@ГригорийПерельман Oh good, I wasn't sure.

Anonymous

As you wish

Down Christopher

12:36 AM

What the... If you have the edit bar up and edit and hit enter it just posts it

Downgoat

O_o either TIO is having moment or cheddar causes infinite loop or related on TIO

Anonymous

@DownChristopher Well, yeah. What behavior did you expect?

Down Christopher

@Mego I didn't know. But it stayed in the grayed out edit bar

ATaco

RProgN1, 24 Bytes ~`.{12/01'rand'C>#U#l?}R

Григорий Перельман

@Downgoat Did TIO ever upgrade to v2?

Anonymous

12:37 AM

I also don't know what you mean by edit bar. If that's something to do with mobile chat, you shouldn't be surprised when it works weirdly.

Downgoat

@ГригорийПерельман still on Nexus AFAIK

Anonymous

@DownChristopher Playing around with chat features should be done in the chat sandbox

Down Christopher

Ok

Григорий Перельман

@Downgoat Cheddar v2

Downgoat

oh, cheddar-v2 is still in dev

Григорий Перельман

12:38 AM

Yeah, but it's also the good one that has features.

Down Christopher

@Mego Except i can't move messages :P

Григорий Перельман

Oh right you have your own TIO thing

Anonymous

Not sure how to help you there, but TNB definitely isn't the place for chat testing

Григорий Перельман

Create a room, thus becoming its RO?

Down Christopher

I can't move messages even in my own room

Post something here

Anonymous

12:42 AM

It may not be possible on mobile chat. I've never tried to move messages on mobile.

Down Christopher

@Mego I am not on mobile

Anonymous

Ok, then to move messages, click the room button on the sidebar, and select move messages

DJMcMayhem

@Mego If you switch to desktop view, you can move single messages. It's extremely inconvenient

Down Christopher

That is cool thanks!

Gah this is not working

DJMcMayhem

The only RO features you can easily use on mobile are pinning and kicking

Anonymous

12:45 AM

And even then, pinning is broken :P

Down Christopher

Found an actual bug

DJMcMayhem

Hehe, yep. That's why the current pinned message is double-pinned rn

Down Christopher

If i star a message then pin it and unstar it stays pinned but will not be in the star board. But this may not be a bug

New Main Posts

1:01 AM

0

Q: Pie of pi pies (Pie day 2017)

In honor of national pie day, create a program that, when given an integer, n, as input, will create a circular "pie" constructed of these smaller pies: The number of pies composing the larger "pie" will be indicated by the nth term of pi. Below are some ascii representations of possible exampl...

DJMcMayhem

@Dennis For a minute there, I thought you were talking about my V, and I was really confused

Riker

@NewMainPosts unclear

@DJMcMayhem lol

Григорий Перельман

@DJMcMayhem Does it support arrays?

DJMcMayhem

Definitely not

Downgoat

Technically string are char arrays...

Riker

1:12 AM

@ГригорийПерельман personally I think tiger woods is overrated

dennis is much better

Anonymous

→ 40 messages moved to talk.tryitonline.net

Anonymous

If I missed any or moved any that shouldn't have been moved, let me know

Dennis

Thanks!

Anonymous

Glad to help :)

Down Christopher

Guys i found the way to get instant rep... You answer the Tetris GoL challenge! Instant rep. I also found the way to make anyone have a headache and want to pass out...

New Sandboxed Posts

1:23 AM

0

A: Sandbox for Proposed Challenges

Golf you a make you an N-quine for great good for great good Introduction Although quines are interesting on their own, they've been explored to death. Quines with strange properties, such as palindromic quines, are also pretty interesting, but each of those challenges are basically one-shots....

Anonymous

I'm fairly certain that answering the Tetris GoL challenge would result in several 500-rep bounties and rep-capping for the foreseeable future

Down Christopher

@Mego Yeah pretty much

I want to answer it to get insane reputation but then I hit the hard part. Answering

Downgoat

Was that the one El'endia and others were working on?

Anonymous

Yep. I was working on it somewhat, but then stupid real life had to get in the way of my fun.

Down Christopher

@Mego How would you even start?

Anonymous

1:32 AM

@DownChristopher Phi wrote up a pretty good series on his blog

Down Christopher

@Mego Still tho

Helka Homba

With a programmable GOL computer + adjoining display it could just be feasible. But building that is nearly as hard

Down Christopher

I was thinking of a challenge that converts processing.js code to GOL

But then a realized that in the universe i doubt it is possible

Helka Homba

1:54 AM

Internet grievance #47: When websites give a date and time but no timezone.

Downgoat

Usually in that case I assume they have localized it for my timezone

Destructible Lemon

@Downgoat BUT THEY USUALLY DON'T

ATaco

2:20 AM

Alright, I made a 2D Tac-it language as a test

Mendeleev

2:32 AM

i asked my sister to make me a pie

she is doing it

Downgoat

.__. What type?

ATaco

+**2
  n

That function squares the number n

Mendeleev

@Downgoat cherry apparently

she's 10 years old

Григорий Перельман

@ATaco ._.

How

ATaco

2*n gives n, n passed to * gives n, n, n... n times passed through + gets the sum of.

DJMcMayhem

2:39 AM

@Mendeleev s/pie/pi

Mendeleev

kek helka just left the Chat Relay account password in a public GH repo

Downgoat

@HelkaHomba you might also want to contact GitHub just in case it got caught in a backup

Helka Homba

3:00 AM

I deleted and remade the repo so it's not a huge deal. I changed the pw right away and the email is old and unused

Mendeleev

OK. I have the repo cloned still, should I delete it?

Helka Homba

@Mendeleev Sure, that'd be nice. New repo without passwords is up at same place github.com/HelkaHomba/oppcgms

Mendeleev

all right, I see it now

ATaco

+*#
 #n

This also Squares n.

For reasons.

Григорий Перельман

Why doesn't +*n work?

ATaco

3:09 AM

There is only one n on when the * is called, so it just passes the n down.

Григорий Перельман

@ATaco Also, why 2 and not 1?

As you explained, it sums n copies of n, so the number seems unused.

ATaco

@+**2
   5

*2 = 5, 5
5

*(5,5) = 5, 5, 5, 5, 5
+(5, 5, 5, 5, 5) = 25

(There @ there's just an IP)

Григорий Перельман

oic

Is there a way to multiply withoutl linking +* together?

ATaco

Nope.

Not yet, anyway.

Григорий Перельман

Is this implemented or is this a spec?

ATaco

3:18 AM

Implemented.

There's no Git, and there might never be, this is mostly me just messing with concepts of Language Design.

Григорий Перельман

Aw

ATaco

It's also not yet TC, nor can it handle strings.

Now I think it is..?

Nevermind!

Mistah Figgins

Is there documentation yet?

ATaco

Well, it's mostly a test, so no.

Mistah Figgins

OK. Feel free to ping me when there is, it looks interesting

ATaco

3:27 AM

 v If this input is truthy, return 13^2, otherwise just return 13.

 1
@?+*\
 | \13
 |  |
 \--/

Mistah Figgins

Can you give me some key rules? where does the IP start?

at the @?

ATaco

Yeah

The line art is all noops, but I like decoration

Destructible Lemon

how does it work

Mistah Figgins

looks like ? checks value, ` and /` redirects. If truthy, the IP evaluates down (13) and stores that as it moves on to the +?

just a guess

And the + combines 13 sets of either 1 or 13, depending on value?

ATaco

The ? Is an if, when true it scans to the right, false it goes down. When it goes to the right, the +*13 thing squares thirteen, then it loops back to the ? And stops there, when it goes down it gets to the thirteen, but can't do anything with the +*, so ignores that and prints the 13

Mistah Figgins

3:33 AM

ok

ATaco

The lines themselves do nothing interesting

I might set up a got...

Git, even

Григорий Перельман

Java or Lua?

ATaco

Lua.

I prefer Lua for Rapid Prototyping, and Java for actual Development.

Destructible Lemon

@MistahFiggins I think they said line art was nops

Mistah Figgins

3:48 AM

@DestructibleLemon It think he just meant the -s and |s, the \ /s seemed relevant to me

ATaco

They are Noops, for now.

Destructible Lemon

explain pls

ATaco

Shh, Writing Documentation now.

Destructible Lemon

also which one gets input

Григорий Перельман

Implicit, I think?

ATaco

3:50 AM

Hardcoded.

The 1 was the input.

Destructible Lemon

that is bad

ATaco

I don't have a function for it yet.

Mistah Figgins

> yet

Destructible Lemon

I applaud your ability to actually work on a language idea

Mistah Figgins

^

And maintain it, potentially

ATaco

3:56 AM

I like language Design.

Mistah Figgins

Ditto. I just have a distinct lack of free time

ATaco

I don't have the free time, I am at work right now.

Григорий Перельман

So you have free time.

ATaco

Well I stole Free Time.

ATaco

4:14 AM

github.com/TehFlaminTaco/TacO

Github

Григорий Перельман

Github lists 0.7% of that project as built in Python.

???

I'm guessing it's the .tac extension.

ATaco

Probably.

Григорий Перельман

No, doesn't seem to be, I looked it up.

Wierd.

ATaco

That or I've steathfully implanted Python.

Григорий Перельман

It is what's being picked up as python though.

ATaco

4:16 AM

It does think the .tac is python. Hmm.

OH WELL.

Григорий Перельман

But python doesn't use .tac files.

ლ(ಠ益ಠლ)

ATaco

@
+
*+*#
# #3
#  #
####

Seems to cube a number.

(The 3 being the input)

Григорий Перельман

What do # do?

ATaco

Nothing, just more noticeable of a Noop than |\/-

@
+
*+*\
| \3
|  |
\__/

Works idendically.

I should probably move to the Langauge Design Room.

feersum

4:35 AM

Algorithm question: How can I generate a canonical representation of (or compare for equality) a recursive tree, i.e. one where the child of a node can point to a node higher up in the tree?

xnor

is this equivalent to a general directed graph?

feersum

Or in other words, it's a directed graph with an ordering for outgoing edges, and a privileged root node.

xnor

well, isomorphism for general graphs is not known to have a poly-time algorithm

i suspect your structure doesn't change this

feersum

Actually I know that comparison for equality can be done efficiently.

xnor

oh, hmm

feersum

4:38 AM

It's a special case of a problam called unification, where there are no free variables.

So the canonical representation is really my question.

xnor

ok, i'm starting to see how this could be possible

each node can be addressed by a series of instructions from the root to take the i'th branch, but not uniquely

feersum

I just realized that I didn't state exactly the problem I want to solve.

If I have root A and it points to itself, I want that to be considered the same as one that has A->B and B->A edges.

So the directed graph description is not accurate.

xnor

can A->B, B->C be converted to A->C in general, if nothing else involves B?

feersum

No.

Helka Homba

@ArtOfCode chat.stackexchange.com/transcript/message/36049003#36049003

Phrancis

4:51 AM

Holy cow.

feersum

So the best thing I can think of so far is generating all trees from smallest to largest and using the unification algorithm to compare them with the tree in question, and keeping the first one that compares equal.

A more precise problem statement could be that a tree is defined by the mapping [series of child indices] -> [number of children at the node reached by following the series]

Григорий Перельман

5:07 AM

CMC: What's the most terifying example of Jelly code that I can show to someone who's never seen Jelly?

feersum

Maybe I can get somewhere by using the unification algorithm on 2 of the nodes in the tree.

ATaco

Anything with strings.

feersum

Maybe, do a DFS traversal of the tree; for each new node reached, use unification to test it for equality with every previously reached node and if it's equal to one of them, make it a pointer to that node (and don't traverse it further).

Unification is O(n) I think, so O(n^3) overall.

ATaco

@sl_________________________
   3 1 1 1 1 8 3 4 1 1 1 1 7
   3 0 0 1 1 7 2 4 1 0 0 0 2
     0 8 4 1       1 8 8 1

The most horrifying Hello World.

Григорий Перельман

I opted to go with “ƝƓỊ⁹Ȥ⁶Ị⁺‘ẋ8_“¤ÐŒ#'/‘¦32BFs21ṖṖCG

ATaco

5:41 AM

That feeling when you write a complicated script and it works first try.

Mistah Figgins

"Is the test wrong?"

ATaco

TacO's shortest infinite loop producing no output is now @"

Compiler errors are for boring people.

Kritixi Lithos

7:33 AM

@Downgoat At least it's spambot proof shrugs

flawr

7:59 AM

@Lynn do you like super cute dragons?

Mendeleev

8:12 AM

CMC: Simple Integer Operation Calculator in Tomato

ASCII-only

8:55 AM

@ATaco This is not horrifying compared to many esolangs e.g. brainfuck/malbolge

Lembik

hi all

Matthew Roh

9:48 AM

Why did noone make a challenge on outputting a beep (aka BEL, \a)

Emigna

Pretty sure I've seen a challenge like that

Matthew Roh

btw, three of my challenges have 20~ likes and thats a good thing

Also, is there a fastest prime calculation challenge?

Emigna

Like this?

Matthew Roh

Its different

It's more like finding all primes between 1 to n

btw the fastest algorithm I know is Eratosthenes sieve revamped

where you erase all even numbers, then from 3, you erase powers of n

Lynn

@flawr awwwww~

Lembik

10:39 AM

hi all

the bounty has landed ... err.. I started a bounty :)

Matthew Roh

11:50 AM

@Lembik on a challenge?

fəˈnɛtɪk

@MatthewRoh It's on this question. Which is likely a fastest code for a NP-complete problem.

Matthew Roh

@fəˈnɛtɪk I know.

btw long code is ideal for C&R because of its complex structure

AdmBorkBork

12:33 PM

@MatthewRoh It was closed and locked.

Matthew Roh

12:56 PM

Ooh

Ton Hospel

Lembik: propertyX ratio > 2

Lembik

1:14 PM

@TonHospel Hi

@TonHospel Really???

How on Earth did you do that?

hi @fəˈnɛtɪk

@fəˈnɛtɪk Can I tempt you to submit an answer to my challenge by any chance? I feel that once there is one answer there may be more

Ton Hospel

Lembik: Lot's of distributed computer power

PhiNotPi

CMC (or should I make this a real challenge): unstable sort: sort a list of comparable objects in ascending order, but in cases where there are several items of equal value, their order in the results should be (randomly/fairly) shuffled.

Fatalize

Might be worthwhile to make that a real challenge

Newly Featured Questions

9

Q: Matrix property X revisited (or the Joy of X)

This challenge is partly an algorithms challenge, partly an optimization challenge and partly simply a fastest code challenge. A T matrix is fully specified by its first row r and first column c. Each remaining element of the matrix is just a copy of the element that is diagonally up and left. T...

code-challenge math combinatorics binary-matrix

Lembik

@TonHospel how long did it take in total?

Martin Ender

1:31 PM

@PhiNotPi sort(shuffle(x)) ... not sure it's worth turning that into a real challenge

Lembik

hi @MartinEnder Sorry if you already said but did you see my paste of the excluded sequences?

Ton Hospel

@Lembik: Completing n=14 took 3 months. Two weeks ago I started n=15 and n=16 on a few computers without much hope (I\ll never finish them) but this morning I unexpectedly got a nice result for n=15 in the log (after only searching 0.012% of the search space)

Martin Ender

I did, not seeing any patterns yet though

PhiNotPi

@MartinEnder yeah I know :/

Lembik

@MartinEnder ok thanks

Fatalize

1:33 PM

The code page table on my github wiki got completely broken even though I haven't done anything to it in weeks…?

Lembik

@TonHospel that's very cool! If feel I should have donated some cpu time!

Martin Ender

brachylog?

Fatalize

Yes

Martin Ender

maybe they changed how markdown tables work?

Lembik

@TonHospel how many cores?

Fatalize

1:34 PM

The Jelly code page didn't change and I basically copied it from here :(

Lembik

@TonHospel it would be great if you wanted to make an OEIS entry

Ton Hospel

@Lembik: n=14 was done using 22 cores

Fatalize

so unless one of my chars is breaking is now…

Lembik

it's all your work so it should be under your name

Martin Ender

@Fatalize it could always be a weird edge case due to one of your characters

Ton Hospel

1:36 PM

@Lembik: n=16 is running on 6 cores now (Most of my computers don't have enough memory), and 6 cores for n=15. But I'll probably stop this stuff shortly since I reached the goal of ratio > 2 and the current searches will take too long

Lembik

@TonHospel If I get a chance I will see if I can get your code to run too

how much RAM does it need on each machine?

Fatalize

Ok I fixed it

Turns out that github changed the way markdown tables work in their wikis

Lembik

@TonHospel it's also interesting to answer the same question for circulant matrices and there are fewer of those

Fatalize

The top left cell was empty so I had spaces in it, and that doesn't work anymore

Turning them to non-breakable spaces works

Lembik

@TonHospel Argh! I awarded you 100 when it should have been 200. Sorry!

Kritixi Lithos

1:39 PM

@fergusq How do you do exponentiation in roda 0.12? As far as I can tell, the ** operator only exists in the master branch under Calculator.java.

Lembik

I had forgotten what I had written

Fatalize

@PhiNotPi After further thought, how do you check that they are shuffled if they are the same?

PhiNotPi

@Fatalize Usually stable/unstable sort has to do with sorting objects by one of their properties, so which object ends up in which final position does make a difference (they aren't identical).

Ton Hospel

@Lembik: n=15 takes about 1G per core. n=16 will be more but it only found a 31-column solution currently. I expect it to grow by at least a factor 3

Fatalize

@PhiNotPi So input would need to be a list of things that more than 1 property then?

PhiNotPi

1:42 PM

yes

Lembik

@TonHospel I expect the number of columns to grow like n log n where log is base 2. n is the number of rows

PhiNotPi

I wonder if there is a quantum algorithm to solve this matrix problem.

Lembik

@PhiNotPi which matrix problem?

PhiNotPi

9

Q: Matrix property X revisited (or the Joy of X)

This challenge is partly an algorithms challenge, partly an optimization challenge and partly simply a fastest code challenge. A T matrix is fully specified by its first row r and first column c. Each remaining element of the matrix is just a copy of the element that is diagonally up and left. T...

code-challenge math combinatorics binary-matrix

Lembik

@PhiNotPi well... Grover's algorithm will give a quadratric speed up

Ton Hospel

1:47 PM

@lembik: The github version of the program finds the low n solutions in seconds

PhiNotPi

Now that I think about it... there are probably some real-world uses for this kind of matrix.

Lembik

@TonHospel Very nice. Would it be hard to modify for circulant matrices?

Ton Hospel

@Lembik: Yes and no. It is currently optimized so much that the code is extremely obscure. Most of that would need to be thrown out and replaced by other crazy optimizations :-)

Lembik

@TonHospel aha :)

New Main Posts

0

Q: Sort useless characters

This challenge is inspired by this very nice answer by TidB. In TidB's answer, every eight character is in the correct order: gnilwoB edoC (Code Bowling backwards). The other strings however are were in a strange, random order. Your challenge is to fix this. Take a string and a positive inte...

code-golf string sorting

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