The Nineteenth Byte

user202729

14:00

> For questions asking for tips on a specific piece of code, to make it a better answer to a programming challenge that is on-topic on this site.

AdmBorkBork

Then xnor's linked question should have been closed as off-topic, rather than being (very) well-received.

Erik the Outgolfer

but that does have a criterion

user202729

@AdmBorkBork That one was a code golf tips.

Anush

is it acceptable to ask project euler questions here?

is there a policy on this?

projecteuler.net/problem=626 looks quite fun for example

Erik the Outgolfer

well, it's pointless to spoil solutions, but I can't think of a reason PPCG should have anti-PE rules

AdmBorkBork

14:03

So tag it programming-puzzle and move on. This ridiculous hostility towards new users to the site because they didn't get everything exactly right is not doing the site any good.

9

user202729

@AdmBorkBork Again, downvoting and closevoting are not hostile.

Anush

@EriktheOutgolfer Thanks. That sounds cool

AdmBorkBork

@Dennis Only if it's intended to be code-golf

Anush

@user202729 for a new user it's really a good idea to be as helpful as possible

including helping rewrite a question if needs be

Erik the Outgolfer

the close reason does contain help

user202729

14:04

@Anush Obviously close vote and explain what is wrong (assume your comment have good tone) is more helpful than just close vote.

Erik the Outgolfer

also, if users don't bother to read the rules, we can't really help much

2

AdmBorkBork

Our rules page sucks

Anush

@EriktheOutgolfer I don't think that's a good attitude

user202729

@AdmBorkBork SE limitation. You can't complain about that.

Anush

not bothering is when you say "For an explanation see X" and then they don't read X

not when they haven't read it in the first place

Dennis

14:06

@AdmBorkBork This is partly about scope. Let's decide what kind of non-challenge questions we want once and for all doesn't list is it possible to do X in Y with restrictions Z.

user202729

@AdmBorkBork "A programming puzzle includes a goal, a partially completed program, and rules outlining how the program can be modified. " Not in this case.

Anush

CMC Solve projecteuler.net/problem=154

Erik the Outgolfer

@Anush when they first visit the site, there is a giant banner at the front that leads them to the tour

user202729

@Anush No spoiler for PE.

Anush

@user202729 ah... does it matter how old the questions are?

Erik the Outgolfer

14:07

spoling PE solutions ruins the fun :/

AdmBorkBork

@user202729 If, as Erik said, they didn't read the rules, but the rules themselves suck, what do you expect a new user to do? Read through five years of Meta history before asking a question?

Anush

I mean github.com/nayuki/Project-Euler-solutions/blob/master/… etc

the internet is full of answers

@EriktheOutgolfer spoiling is definitely bad

user202729

@AdmBorkBork Regardless of the rules, downvoting and closevoting are not hostile. Besides they can just look at the other questions.

Anush

maybe I should ask on meta

Erik the Outgolfer

@AdmBorkBork the How to Ask text specifies:

AdmBorkBork

14:09

@user202729 To a brand-new user, they can be perceived as hostile very easily.

Dennis

21

A: What are the policies for threads relating to Facebook Puzzles, Project Euler, UVa, SPOJ, etc.?

There are three reasons why I think Project Euler etc. questions shouldn't be posted here. The first is copyright. The question submitter ... represents, warrants and agrees that it will not contribute any Subscriber Content that (a) infringes, violates or otherwise interferes with any copy...

user202729

@Anush Meta what? Spoiler?

@AdmBorkBork Everything can be perceived as hostile. But if they are not, they are not. finding SO meta

Erik the Outgolfer

> All challenge questions on this site should have: [...] An objective primary winning criterion, so that it is possible to indisputably decide which entry should win.

Anush

@user202729 ppcg meta

@Dennis you got there before me

Dennis

We usually just say ninja'd. :P

user202729

14:10

26

Q: Does my guidance to a new member strike the tone SO is trying to achieve?

I've started down voting and commenting to provide friendly but firm guidance to new members. Here is an example from C# Closures in LINQ expressions: Welcome to StackOverflow. You will receive better responses to your questions if the code compiles. Consider pasting your example in to dotnet...

Anush

who writes PE questions?

user202729

@Anush projecteuler.chat/viewtopic.php?f=26&t=510

Erik the Outgolfer

policies don't need past events to exist

Anush

@user202729 I mean can I pose a question?

is PE funded by someone

who is this team?

AdmBorkBork

@Dennis So it doesn't fit the tips precisely. Rather than downvoting into oblivion and close-voting it without comments, perhaps we could instead slightly tweak the question so it fits the site. It's pretty clear what the OP intended -- is a CPP quine possible?

user202729

14:13

@Anush Why do you ask me...?

Anush

@user202729 I thought you might know :)

Erik the Outgolfer

@Anush that doesn't look like an on-topic question for this site or its meta...

user202729

@AdmBorkBork ... (1) there are 0 downvotes. (2) there are many comments explaining what's the problem. (3) I have no idea what the OP intended. Macros can't print.

Dennis

@AdmBorkBork But is a CPP quine possible is not on topic afaik. How would you change the question?

2

user202729

I see zero hostility here.

(I decide to star to agree, because others do it anyway)

Anush

14:15

@EriktheOutgolfer I wasn't going to ask if PE is funded by someone on the ppcg meta ! :)

Erik the Outgolfer

ah, I thought you meant "can I pose this question? ..."

Anush

@EriktheOutgolfer no :) I meant can I pose a question for PE on the PE site

quora.com/…

Erik the Outgolfer

um, read the rules there to make sure?

user202729

@Anush Yes you can, see my link above.

Anush

yes thanks.. this has all got out of order :)

"My friend key is" what's a friend key??

user202729

14:18

@Anush You enter it into the page projecteuler.net/friends and it let you track the progress of your friends.

AdmBorkBork

@Dennis I said earlier, remove the tips and tag it programming-puzzle. Slightly tweak the wording to remove the "Is it possible?" vibe and assume it is possible, then ask the community to do so. If it goes unanswered, well, so be it.

Anush

@user202729 thanks

Erik the Outgolfer

where is the criterion though

HyperNeutrino

Final Feedback before posting?

AdmBorkBork

@EriktheOutgolfer programming-puzzle implies first-past-the-post

Adám

14:20

Don't forget to join our live webinar - Creating and managing your own User Commands - on Thursday 17 May at 15:00 UTC where Adám will demonstrate how to create and manage custom user commands within Dyalog APL https://dyalog.tv/Webinar

Tweeted by dyalogapl on May 14, 2018 at 1:00 PM

user202729

@HyperNeutrino +1. I have not checked the test cases because it's not easy to do so (Mathematica has ArrayPlot function, very useful for visualization)

AdmBorkBork

@Dennis Thanks for linking this Meta - first I've seen it.

Anush

Some of these PE questions are hard to read! "A best approximation to a real number x for the denominator bound d is a rational number r/s (in reduced form) with s ≤ d, so that any rational number p/q which is closer to x than r/s has q > d."

Erik the Outgolfer

@AdmBorkBork how? it's not a criterion tag, unless it's tagged code-challenge and it says "first post wins", which is discouraged anyway

HyperNeutrino

3

A: Sandbox for Proposed Challenges

Are there mountain rings? code-golf matrix Challenge Given a matrix of positive integers, determine if there are any "rings" of mountains. The formal definition for this challenge is: given a matrix of positive integers, is there any positive integer n for which there is a closed ring of cells ...

(more visibility)

Anush

14:21

"Usually the best approximation to a real number is uniquely determined for all denominator bounds. However, there are some exceptions, e.g. 9/40 has the two best approximations 1/4 and 1/5 for the denominator bound 6. We shall call a real number x ambiguous, if there is at least one denominator bound for which x possesses two best approximations. Clearly, an ambiguous number is necessarily rational."

"How many ambiguous numbers x = p/q, 0 < x < 1/100, are there whose denominator q does not exceed 10^8?"

oh what is that chat room for?

user202729

(disclaimer: I'm not very active there)

Anush

wow this is a great question! projecteuler.net/problem=275

I really want to pose it on ppcg now :)

(but I won't...)

DJMcMayhem

> For discussion about programming, math, and science, and related topics. Not about PPCG (the site itself) or golfing.

It's a fun room

Anush

@DJMcMayhem cool!

HyperNeutrino

wait p&s belongs to PPCG? oocool

AdmBorkBork

14:24

@EriktheOutgolfer Now you're just splitting hairs, which is exactly my point about perceived hostility to new users.

user202729

@AdmBorkBork Whether programming puzzles are on topic is ... well, disputed. It's not surprising that there are debates around the question.

AdmBorkBork

That's a fair enough point.

user202729

Besides, a new user post something here doesn't make it automatically on-topic. There are no reason to treat them specially.

(cont 2 above) Even programming puzzles by experienced users are not always well received.

HyperNeutrino

on the topic of experiences users posting poorly received puzzles, I posted to main

:P hope it isn't poorly-received though because it's been in sandbox for months

user202729

@HyperNeutrino >.< Not count that one. That's not a programming-puzzle.

HyperNeutrino

14:29

oh you meant programming puzzles as in literal programming-puzzles

my bad

New Main Posts

1

Q: Are there mountain rings?

Challenge Given a matrix of positive integers, determine if there are any "rings" of mountains. The formal definition for this challenge is: given a matrix of positive integers, is there any positive integer n for which there is a closed ring of cells in the matrix that are strictly greater than...

code-golf matrix

Erik the Outgolfer

@NewMainPosts excellent dude, only 4 minutes

user202729

@EriktheOutgolfer I read 6 minutes.

@NewMainPosts Not suitable for Jelly :/

HyperNeutrino

oof :/

AdmBorkBork

I expect a pretty short MATL answer, though.

HyperNeutrino

14:36

would make sense

user202729

@AdmBorkBork ... I'm not sure what builtins it have...

AdmBorkBork

I don't know MATL, but I know it's really good at manipulating matrices.

Anush

I like this old question and feel we need a new version of it codegolf.stackexchange.com/questions/10656/…

which actually follows our rules :)

user202729

@Anush Popcon hardly works.

Anush

@user202729 does popcorn still exist on ppcg?

user202729

14:42

@Anush ... yes.

Anush

oh!

I saw attempts to get rid of it

user202729

Even if they're popcon, they're still expected to have winning criteria, just not "objective". And the valid criteria must be objective.

Dennis

@Anush It does. But since votes are mostly distributed at random, popcons are only marginally better than a lottery.

Anush

CMC Find the smallest set of integers which can make any integer 0..100 using +,-,*,/ . You can use parentheses just to group the arithmetic, nothing else.

user202729

@Anush How to define "smallest"?

Anush

14:45

@user202729 the size of the set is the number of integers

user202729

@NewMainPosts Getting the "larger than" part is not hard, but BFS is hard. tio.run/##y0rNyan8///…

Cows quack

@Anush can you repeat those numbers?

AdmBorkBork

@EriktheOutgolfer A meta showing that programming-puzzle implies first post wins.

Anush

@Cowsquack no... so I shouldn't have called it a set. Smallest multi-set

user202729

@Anush Is negation allowed?

Anush

14:49

@user202729 yes

DJMcMayhem

@Anush {1}

Anush

@DJMcMayhem ?

Erik the Outgolfer

1+1+1+...

user202729

@AdmBorkBork Why are you linking to an answer?

Anush

@DJMcMayhem you can't use the 1 more than once

@EriktheOutgolfer ^^

AdmBorkBork

14:50

@user202729 Point #1 in the linked answer

user202729

An obvious submission is {1,2,4,8,16,32,64} for score 7. (and 0=8/4-2)

DJMcMayhem

@Anush oh, you didn't say that...

Anush

@DJMcMayhem I did :)

DJMcMayhem

Not in the CMC though

Anush

@DJMcMayhem right.. in an answer about it. I don't know how to edit a CMC

user202729

14:52

(wait wrong reply?)

Erik the Outgolfer

you only have 2.5' to edit it

hover over the message, click the blue arrow ont he left and click "edit"

Anush

@user202729 that works... can we do 6?

user202729

@Anush Either press up arrow button or click at the down arrow to the left of a message and click edit.

Anush

@EriktheOutgolfer yes thank you.. I was too late

user202729

@AdmBorkBork It's not even the highest voted one.

DJMcMayhem

14:53

@Anush If you'd like me to edit it, I can

Anush

@DJMcMayhem yes please

user202729

@Anush (because moderators have powerful abilities)

Anush

Find the smallest multi-set of integers which can make any integer 0..100 using +,-,*,/ . You can use parentheses just to group the arithmetic, nothing else. The size of a multi-set is the number of integers in it. E.g. {7,7,7,6} has size 4. You can use each element of the multi-set up to once.

I have no idea what the correct brackets are for multisets

so the first question is, it is less than 7?

AdmBorkBork

@user202729 xnor's answer is a meta-answer to the question, rather than a direct answer

@user202729 I'd be willing to bet this is optimal.

user202729

@AdmBorkBork I doubt it.

AdmBorkBork

15:01

The only other optimality I could think of would be to take one plus the primes up to sqrt(100)

but I don't think that approach would give you enough coverage

user202729

Let me write a brute force program.

user202729

15:20

For {1,2,4,8,15} (score 5) I get

run:
15	1 2 4 8 15 / / * *
16	1 2 4 8 15 / / * +
60	1 2 4 8 15 * / / *
61	1 2 4 8 15 * / / +
62	1 2 4 8 15 * + / /
57	1 2 4 8 15 - * * -
30	1 2 4 8 15 - * - *
31	1 2 4 8 15 - * - +
27	1 2 4 8 15 - * + -
22	1 2 4 8 15 - - * *
23	1 2 4 8 15 - - * +
10	1 2 4 8 15 - - - -
13	1 2 4 8 15 - - + *
14	1 2 4 8 15 - - + +
7	1 2 4 8 15 - + * -
5	1 2 4 8 15 - + - *
6	1 2 4 8 15 - + - +
2	1 2 4 8 15 - + + -
0	1 2 4 8 15 - + + +
46	1 2 4 8 15 + * / /
91	1 2 4 8 15 + * - -
94	1 2 4 8 15 + * + *
95	1 2 4 8 15 + * + +

DJMcMayhem

@user202729 That's really incredible. Postfix notation, I assume?

Also, integer or float division?

user202729

@DJMcMayhem Actually after a while I feel stupid. (1,3,9,27,81) can reach all numbers in [1..100] with just + and - (balanced ternary) and 27/9-3=0.

That is, unless my brute force program can produce some set with size 4.

Float.

DJMcMayhem

What if tiebreaker is smaller sum of the set? :P

user202729

Without concatenation.

NieDzejkob

Can a b c d - e * / / be expressed with all the operators at the end? Might be a logic flaw in your bruteforcer

DJMcMayhem

15:28

@NieDzejkob ((e * (c-d)) / b) / a)

Although I might have my precedence backwards. I don't know if a b / is a/b or b/a

NieDzejkob

that's commutativity

but I don't want an infix expression

DJMcMayhem

@NieDzejkob Division is not commutative

NieDzejkob

I know...

actually, I think neither word is correct - precedence is the order of operations, not operands

user202729

@NieDzejkob ... what?

How is that a flag?

x y / is x / y.

DJMcMayhem

On a random semi-related note, I'm working on a new language with prefix notation. Is this algorithm a good approach for how to parse prefix expressions?

Anush

15:33

@DJMcMayhem float division

NieDzejkob

oh, I assumed that the beginning stays as 1 2 4 8 15

DJMcMayhem

(sorry for bitly, it's a long TIO link)

Anush

what is the min size so far?

user202729

@DJMcMayhem No upperbound for multiline.

@Anush 5.

NieDzejkob

is that the case, or do you change the order after you go through all operator combinations?

Anush

15:34

@user202729 oh cool... (1,3,9,27,81) ?

user202729

My brute forcer:
https://tio.run/##hVTtbqMwEPwdnoL2pAYaSEpbnXQB8gj3Ak0VGXATq8SOsGnhIp49t/6AmKRV/9me2dn1eNf54RBu8/x0@kVoXtYFTgjjosJov3KGow@cC1ZZB6iqUGvvyy2riNjZQfkeid3KcbgolkutkBAqVi7l6TEKouAp@BNED108phSszkq8crlA@Xt8Hf3Gqn1dIoOoQpKMsRKkIonWtDhKTUzrvZuXiHOXHTbiiIoiDaOA11kaPgYgkYZPQUE@0vAZ6Dqrm6My98y6CcyiDaQAqPhHZ8I/ich3nt5McsSxkodKimJZYVFX1G1mbTwGIesAhpcg1DKA95cgVDiACwl2zsTswyh2Osf5YKRwM6@mnGwpLlxCC9zI6sibp9Y3KeVzTv5hz1dFLxauqFr3UPMdoVsXUSZ2uHLBrwxXgCvn5xLeZLDyKH9ROq@@rM34/y2e6aSzaMyG2yiyOjUZ7LNO1asBXesqUtWCAihK@@GlYnaIZzNj/qR/NEa5cNtUB5@zaEHZJBn3Wj@JcBg93t150lgf5NLBYR8kBKE1VmFfVHeRq7nOZR@kqo…

Anush

nice

user202729

Which numbers can be used in the initial set? Floats? Negative? Zero? (no idea why I need zero anyway)

NieDzejkob

if(not found[i]) how does that work? not is a python thing, C++ has !

user202729

@NieDzejkob Because not all keyboards have !.

I forgot what is that called..

"alternative tokens".

NieDzejkob

15:40

TIL that exists

Mr. Xcoder

@user202729 Whether programming puzzles are on topic is ... well, disputed. Yet this site is called Programming Puzzles & Code Golf.

Dennis

A problem we've been trying to correct, but the majority favors tradition over making sense.

39

A: Should we change our name?

No change The current name is still accurate, or at least it is close enough. It also has historical significance. Changing our name may make it harder for people to find us. Also, nochange.stackexchange.com has a nice ring to it.

user202729

@Mr.Xcoder Besides, SE doesn't care much anyway.

AdmBorkBork

@user202729 Neat! I guess the powers-of-two is not optimal after all. :)

Mr. Xcoder

I am in favour of Code Sport and Code Games, so +1 from me.

CMC: All contiguous sub-matrices of a given integer matrix.

user202729

15:50

I'm trying to brute force all 4 subsets. Seems no hope.

Meta brute forcer:
https://tio.run/##hVVNb@IwED2TX@FqpTaBpBCo9kASjqs97G21J4pQPgxYDTaKnTYsym9nx3Y@HNpuD6i23/ObyfPMND2dvH2aXq/fCE3zMsMhYVwUOD6urO7oFaeCFcZBXBTx2dzne1YQcTAvpcdYHFaWxUW2XGqFkFCxQpQHw9OMlUmOV4iLOH0J3l/YseJY5nGDqNhhwlju@jNfoiXNQBHT8ojSPOYcsdNWXOIsizzf5WUSeXMXBCJv4WbkNfKe6sDSMVEa56ndrCu3WZxdKQAqzsUa8Tci0oOtN6M05ljJQx5ZtiywKAuKqsk5GIIQtQO9WxBy6cDxLQgZduBUgrU1avaeH1i1Zb0ykqHELikne4ozRGiGK5kd2dlqfRdR/sjJX2w7KunpFInijE4lPxC6RzFl4oALBH4luABc@f4o4W0CK5vytdLZODK3xv1P8UQHnfhDNnyNIqvTJoJ5Vqt8NaBzXfkqW1AARWk/vFTATsFk0pg/ah@NUS7QOdKX@yhaUJZIwu2zE/rY8@f397Y01gG5qHPYAQlBaInVtQ@yu4lVvY9lHkSqjCr3…

HyperNeutrino

@Mr.Xcoder Jelly, 6 bytes: ẆZ€Ẇ€Ẏ

I think

Mr. Xcoder

I have something slightly different

But also 6 bytes.

HyperNeutrino

ẆZẆ$€Ẏ also would work

Mr. Xcoder

Mine's Ẇ€Z$⁺Ẏ

HyperNeutrino

isn't that 5 bytes

Mr. Xcoder

16:03

Nope :p

HyperNeutrino

oh

right :P

yeah I considered using ^+ actually

Mr. Xcoder

(trying to solve your challenge :p)

HyperNeutrino

lol

Mr. Xcoder

Anyway, I need 2 inputs which is not very friendly with my Jelly golfing skills

HyperNeutrino

oh rip. matrix and n?

Mr. Xcoder

16:04

You shall expect a lot of superscripts :P

Yup

HyperNeutrino

lol :P

you really like superscripts and I really like $ apparently

Mr. Xcoder

@HyperNeutrino Are you up for a CMC or two in JHT? I have some ideas and that room's too inactive lately

HyperNeutrino

Sure

Pavel

16:32

Anyone know how to assign to a global var from a dfn in APL

Anush

are we still at 5?

H.PWiz

@Pavel I believe you can do so with ∘←. Although this isn't intended (or recommended)

Pavel

ty

moonheart08

How do you calculate the period of a randomizer? I realised that the popcnt instruction in x86-64 might be useful for random shenanigans, and i'm trying to find out the period of a randomizer i made as a result

Adám

@Pavel What H.PWiz said, but if the global already exists, ⊢← is intended and supported (although the functional crowd may yell at you).

Anush

16:40

@user202729 Does this mean that actually we can't get 52 this way?

Pavel

@Adám I have the hackiest solution to problem 1 of the student competition

Adám

@Pavel Phase 1 or phase 2?

Pavel

@Adám Phase 1

I can't think of a way to do it functionally

Adám

@Pavel One sec, let me find it.

moonheart08

Here's the randomizer's SRC. Quite simple, just gets the current pop count (number of on bits) of the seed number, adds it, and then does a left shift.
unsigned long qrand() {
randn += __builtin_popcountl(randn);
randn <<= 1;
return randn;
}

it looks random to me, but i'd love to know the actual period

Adám

16:42

Oh, that's the building-starring thing.

Pavel

yep

Adám

@Pavel Do the best you can. Go through the list of functions and operators and think for each one whether it could be useful.

Pavel

I need for loops ;-;

Adám

@Pavel I'm messing about with Phase 2's XOR "problem".

@Pavel Good thing you're beginning early.

CMC do-x-without-y: Given two Booleans, produce their XOR without using any built-ins.

HyperNeutrino

what do you mean by "built-in"

DJMcMayhem

16:49

@Adám To clarify, you mean no XOR built-ins, not "any built-ins", correct?

Adám

@DJMcMayhem No, I mean no built-ins whatsoever.

@HyperNeutrino Well, it depends on the language obviously, but for most programming languages, things like + and sum() etc.

DJMcMayhem

What does that even mean?

moonheart08

.. you can't do calculations without builtins?

DJMcMayhem

@Adám Does that mean all 8 commands are banned in brain-flak?

moonheart08

you'd need a language that has the default effect of taking the XOR of two numbers

FrownyFrog

16:51

hmmmmmmmmm

Adám

@DJMcMayhem I'm not sure. Hence a CMC with a tag saying it is a bad CMC.

HyperNeutrino

oof

Cows quack

that failed

FrownyFrog

clearly a built in

Cows quack

ah I misunderstood, I thought no xor builtin

Adám

16:55

I can do it in 18 bytes in APL.

FrownyFrog

it’s a koan

you can solve it in your mind

but can’t communicate the solution outwards

DJMcMayhem

@Adám I honestly have no clue what is or isn't valid. Does this work? lambda a,b:(a and b==False)or(b and a==False)

Or is == a builtin?

Adám

@DJMcMayhem No, because you use == and and.

DJMcMayhem

OK, well neither of those show up here

FrownyFrog

Perhaps you have to use undocumented features

Adám

16:57

APL (Dyalog Unicode), 18 bytes Spoiler

dzaima

@Adám Prolog, 15 bytes. does this count?

HyperNeutrino

lambda x,y:0 if x else 1if y else 1if x else 0 maybe?

Adám

@DJMcMayhem Right, that's the list of built-in function. You can't use built-in operators either.

@HyperNeutrino Yes. There you go!

HyperNeutrino

:P ok

Adám

@dzaima Yes, it appears so. So it just checks whether it was called with any of these argument?

@dzaima Can you then translate that to Brachylog or does that then entail "built-ins"?

dzaima

17:03

@Adám I don't know brachylog :p

Adám

It should be possible in any language that has if statements.

dzaima

@Adám it tries to find a proof that f called with those arguments exists and I've defined it 2 cases. Prolog doesn't have natural true/false values so I chose 0 and 1

HyperNeutrino

anyway gtg o/

dzaima

@Adám SOGL, 5 bytes: ??0←1. Is ← a built-in? It's a way to end a codeblock - here an if, but has a side-effect of ending the program too

Adám

@dzaima That's fine.

Proper structured APL programming at 36 bytes: Try it online!

Neil

17:15

@HyperNeutrino can't you simplify that to lambda x,y:0 if x else 1if y else x?

dzaima

@Neil @HyperNeutrino don't both not work?

Neil

@dzaima ah, precedence issue, lambda x,y:(0if x else y)if y else x

New Meta Posts

17:43

0

Q: tag:self-referential - Isn't this just a quine?

In 2016 we decided to have the self-referential tag: New Tag Proposal: Self-Referential Since then we've had 8 questions under this. I think they're honestly just quines. Can/should we revisit this?

discussion

DJMcMayhem

@NewMetaPosts Sure took ya long enough

New Main Posts

1

Q: Up and down, up and down

Challenge: Given a positive integer input n, create a vector that follows this pattern: 0 1 0 -1 -2 -1 0 1 2 3 2 1 0 -1 -2 -3 -4 -3 -2 -1 ... ±(n-1) ±n Or, explained with words: The vector starts at 0, and makes increments of 1 to until it reaches the smallest odd integer that isn't ...

code-golf sequence integer

Mr. Xcoder

@user202729 You are so damn right!

New Sandboxed Posts

18:03

0

A: Sandbox for Proposed Challenges

Merge two code in two languages into a polyglot. E.g. If you choose C & Python 3, you can merge main(){puts("a");} and print(6) into #define print(x) main(){puts("a");} print(6) popularity-contest (for it's hard to have a score on language difficulty, optimizy, etc.)

Hat Wizard

CMC: What is the shortest string consisting of only alphabetic characters that gets no results on ddg?

(I used duckduckgo rather than google because google's tracking makes it user specific)

Adám

@HatWizard I can do 7 so far.

Hat Wizard

Which 7? The best I've done is 9.

Adám

@HatWizard zqxjqzq

@HatWizard Z, Q, X, and J occur significantly less frequently than all other letters (in English at least).

Hat Wizard

qxqvjq

I did a 2-gram of duck-duck go results earlier and found that qv was the rarest 2-gram.

Adám

18:16

@HatWizard I get 2 results.

Mr. Xcoder

Same here.

Hat Wizard

Huh, I get none. Maybe ddg is not user independent

Adám

Mr. Xcoder

Impostors! :P

Hat Wizard

@Adám Oh you are searching from the uk. I am searching from "All regions".

Adám

18:18

@HatWizard No, the "switch" is off. Also, All regions should be a superset of UK, no?

Hat Wizard

Huh. When I switch uk on I get those same results, but when I'm on all regions I get none

Oh you also have safe search on.

If you search with safe search off they go away for some reason.

Adám

@HatWizard Again, that should make fewer, no?

AdmBorkBork

Related -- Googlewhacking.

Hat Wizard

I would think so, but perhaps those links are just too safe.

Adám

Hat Wizard

18:21

The plot thickens

For proof.

I now have no idea. Everything I said was true, when I turn safe search on or switch to the uk the results do appear.

AdmBorkBork

Interesting -- I'm searching all regions with safe search:strict and see the two results

Hat Wizard

When I search in private mode I get the results, so ddg must store some cookies.

So I guess that is not a valid 6 solution

Adám

Hey, then I'm still leading with 7.

dzaima

qvszwz

Adám

@dzaima Well, that didn't last long.

@EriktheOutgolfer How?

Erik the Outgolfer

18:33

@Adám sorry, looks like I omitted the quotes

so it's actually 8 chars: "qvszwz"

Hat Wizard

I'd be really surprised if there was a 5

Erik the Outgolfer

@Adám's doesn't have quotes

Hat Wizard

Nah I say you get the quotes for free

Adám

@HatWizard But that wasn't in the CMC. It did say only alphabetic characters

Erik the Outgolfer

btw why is dzaima's qvszwz starred o_o

dzaima

18:36

@EriktheOutgolfer guessing someone wants ddg to notice it :p

Stewie Griffin

@Dennis I seem to recall that the help center had a section about selecting good titles, and a recommendation was: "Project Euler #101: Task description"

Hat Wizard

@Adám I would just consider the quotes part of searching it properly.

Adám

@dzaima I think SE chat has a robots.txt to fight off search engines.

Erik the Outgolfer

@Adám you mean chat?

Hat Wizard

robots.txt?

Erik the Outgolfer

18:38

it's not really good for SE to make posts unsearchable

@StewieGriffin which help center?

Pavel

@HatWizard robots.txt is a text file that tells bots what they're allowed to look at on a page

Adám

Robots exclusion standard

The robots exclusion standard, also known as the robots exclusion protocol or simply robots.txt, is a standard used by websites to communicate with web crawlers and other web robots. The standard specifies how to inform the web robot about which areas of the website should not be processed or scanned. Robots are often used by search engines to categorize websites. Not all robots cooperate with the standard; email harvesters, spambots, malware, and robots that scan for security vulnerabilities may even start with the portions of the website where they have been told to stay out. The standard is...

Pavel

You don't have to obey robots.txt but Google's scraper does to be nice

Hat Wizard

Can I view the robots.txt?

Adám

@HatWizard chat.stackexchange.com/robots.txt

Pavel

18:40

#
# Yahoo bot is evil.
#
User-agent: Slurp
Disallow: /

Hat Wizard

Oh wow they disallow just about everything

Pavel

yep

Stewie Griffin

@EriktheOutgolfer That one... I searched it too and couldn't find it either... But I think it was there, once upon a time...

AdmBorkBork

@Pavel Hahaha

Dehodson

Hey all, trying to do a bit of JS golfing here. Is this an acceptable place to ask for tips or advice for improving my solution? This isn't for a puzzle on PPCG, just a recreational thing I'm doing.

Adám

18:44

@Dehodson Yes, absolutely on-topic.

Hat Wizard

You can ask here in chat or make more specific questions on main

DJMcMayhem

@Dehodson Welcome :)

Dehodson

Awesome, thanks @Adám, @HatWizard. I'm trying to write a function that accepts a table's id and a string and hides all table rows that don't have a cell equal to that string. Here's what I have so far:
(d,z)=>document[l='querySelectorAll'](`#${d} tr`).forEach(x=>Array.from(x[l]('td')).some(y=>(x.style.display=y.innerText==z?'inherit':'none')[0]=='i'))

@DJMcMayhem Thanks! :)

Hat Wizard

I don't know JS, but It looks like currying can save you a byte.

Adám

@Dehodson Markdown doesn't work in multi-line messages. But if you post multiple messages right after each other, they'll look like a single message.

Dehodson

18:48

@HatWizard Good catch! Down to 152 bytes :P

@Adám thanks for the tips, obviously I'm new to this!

Hat Wizard

Editing messages with @ in them repings people by the way. I don't mind it myself, but others sometimes do.

DJMcMayhem

Hmm. I wonder if editing an old message with a ping also ends up in your SE inbox

Hat Wizard

There is a limit on how long you can edit, unless you are talking about mod super powers

Stewie Griffin

@DJMcMayhem you only have about a minute don't you??

DJMcMayhem

I don't ;)

Erik the Outgolfer

18:54

@Dehodson what more on-topic for a site's main chat room than the site's topic ;)

Dehodson

@EriktheOutgolfer True, but I didn't know if this was meta discussion only or something! :P

Stewie Griffin

Apologies Mr. Mod! I'll rephrase: Mere mortals only have about a minute?

DJMcMayhem

lol

AdmBorkBork

@EriktheOutgolfer Discussing (natural) language nuances, or food ... oh wait, you said "on-topic," not "popular"

7

DJMcMayhem

@StewieGriffin I believe it's 2 minutes

Adám

18:56

@Dehodson You can experiment with chat's features in the sandbox.

@DJMcMayhem I think 30 seconds.

dzaima

@Adám nope, definitely ~2 minutes

DJMcMayhem

20

Q: Can we have more than 2 minutes to edit comments in chat?

Is it possible to increase or remove the edit time limit on comments in chat? I think that 120 seconds is a bit of a short period in order to correct any typos or errors. Consider this: Many of the chat rooms, including the Chat Feedback room are left for several hours or days before people r...

feature-request status-declined chat time-limit

Stewie Griffin

@Dehodson Note that there might not be many JS golfing experts in the chat room at any given time, and chat messages drown, so you might not get much feedback. You might be lucky though!

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