The Nineteenth Byte

Leaky Nun

2:00 PM

Any golfing tips for searching in OEIS?

DJMcMayhem

@LeakyNun Yeah, I was thinking about it. I'm not sure if I have enough time right now, but I might answer that.

Leaky Nun

@DJMcMayhem nice

Sp3000

@LeakyNun keyword: nice, keyword: core, keyword: fini, keyword: dumb

(depends what you mean by golfing tips, really)

Leaky Nun

@Sp3000 well, for example, remove the whitespace after the colon

Sp3000

Oh... that sort of golfing...

Wait, how are results measured? Shortest query that gives a certain sequence as first result?

Leaky Nun

2:06 PM

> For example, +30 and 1086 for A000045.
The +30 is the sequence's query score -- how well it matches the query.
You get 100 points for matching ordering (for example, having 1 3 5 not 1 2 3 4 5 when the query is 1 3 5).
You get 10 points for matching terms in certain lines (for example, sequence data counts more, and sequence number counts a lot more).

The 1086 is the number of sequences in the database that reference the given sequence.

The "relevance" sort is by query score, with ties broken by reference count.

oeis.org/hints.html

Sp3000

Not quite what I was asking, but okay

Leaky Nun

@Sp3000 what were you asking?

By the way, new challenge in 15 minutes

Sp3000

I was assuming there was some sort of scoring criteria for this "golf" of yours - I was assuming something like least bytes query that gave an input sequence as the first result

Leaky Nun

This time, it is not an alphabet challenge.

@Sp3000 oh, well I don't have an idea

Poll: is this statement true or false?

> Every even prime larger than 2 is odd.

Nathan Merrill

false

no, its true

yeah, its true

all([]) returns true

Leaky Nun

2:15 PM

@NathanMerrill got'cha

Relevant article in wiki:

Vacuous truth

In mathematics and logic, a vacuous truth is a statement that asserts that all members of the empty set have a certain property. For example, the statement "all cell phones in the room are turned off" will be true whenever there are no cell phones in the room. In this case, the statement "all cell phones in the room are turned on" would also be vacuously true, as would the conjunction of the two: "all cell phones in the room are turned on and turned off". More formally, a relatively well-defined usage refers to a conditional statement with a false antecedent. One example of such a statement is...

Nathan Merrill

although, I'm not sure why we define all([]) to be true

Leaky Nun

@NathanMerrill see above

Nathan Merrill

right, but why do we define it that way?

Leaky Nun

because of the way conditionals in logic work

If p is false, then p=>q must be true

Nathan Merrill

how is that relevant?

Maltysen

2:17 PM

@NathanMerrill same reason 0!=1

Leaky Nun

the statement forall X in S: Q is equivalent to (X in S) => Q

here X is the empty set (even primes larger than 2)

Or 0^0 = 1

@DJMcMayhem no

@DJMcMayhem nope

Not the 0^0 one, that's different

Nathan Merrill

2:17 PM

@Maltysen that makes math easier (which I agree with), but I can't say that for all([])

DJMcMayhem

Fine. But it is true

Leaky Nun

@NathanMerrill treat it as the empty product

@NathanMerrill we know that all(X) == all(X+[True])

then backtrack to X==[], just like the case 0!=1

Maltysen

Also & is * and or is +

Leaky Nun

@NathanMerrill in logic, all([]) means forall X in []: Y which is equivalent to (X in []) => Y

since X in [] must be false, the conditional must be true

DJMcMayhem

Or you could say instead of "every x in l is true", "no x in l is false"

Maltysen

2:21 PM

@DJMcMayhem idk bout that. Lim x to 0 of x^x is 1, depends on you how you define 0^0, or even if undefined

Nathan Merrill

so, basically all(list) -> bool(list.pop()) && all(list)

Leaky Nun

@Maltysen 0^0 is undefined

@NathanMerrill yep

Maltysen

@LeakyNun again, it really depends

Nathan Merrill

and if all([]) is false, then all([True,True]) would be false

Leaky Nun

@Maltysen 0^0 is undefined by convention

@NathanMerrill bingo

DJMcMayhem

2:22 PM

@LeakyNun I've always heard that 0^0 is 1 by convention

Sp3000

0^0 is indeterminate form since lim x->0 0^x != lim y->0 y^0 (and you can construct other differing limits too)

Leaky Nun

@DJMcMayhem no, 0!=1 by convention

Sp3000

The 0^0 = 1 in programming is just programming convention

Not maths

Leaky Nun

^

FryAmTheEggman

wolframalpha.com/input/?i=limit+x-%3E0+x%5Ex

Maltysen

2:24 PM

@Sp3000 yeah, but doesn't it limit to 1 if you do it simultaneously?

FryAmTheEggman

As long as it is in the real domain, I think zero to the power of zero is one, but if you consider the complex domain it's clearly undefined.

Leaky Nun

@FryAmTheEggman the limit of x^x when x->0 is 1, that does not mean that 0^0 is 1

@FryAmTheEggman its limit is one, but itself is not one

@Maltysen that doesn't mean 0^0 == 1

Maltysen

@LeakyNun I know that's what I told @DJMcMayhem

DJMcMayhem

@Sp3000 I always thought it was in math too, but you probably know more math than me, so I believe you

FryAmTheEggman

That's true, but I think the limit makes the most sense as a definition. I'm sure many people disagree but I think at that point it's mostly philosophical?

Leaky Nun

2:26 PM

@FryAmTheEggman the limit is not the definition

the limit of x/x as x->0 is also 1, does that make 0/0 equal to 1?

Poke

There are mathematical arguments that 0^0==1

something about the binomial theorem iirc

Leaky Nun

@Poke that's 0!=1

Poke

no it's x^0=1 for all x

Leaky Nun

@Poke why?

Maltysen

@Poke but 0^x =0 for all x>0

That's the confusion

FryAmTheEggman

2:28 PM

@LeakyNun Yeah, I guess you're right, don't mind me, then :P

Sp3000

@Maltysen By that argument, lim x->0 (x/x) = 1 so 0/0 should be 1, but lim x->0 (2x/x) = 2

You can't really just "do it simultaneously" for one and assume it'll always work - the limit should always be the same if it's actually that value

(I hope I'm remembering this right, I just remember lots of fun examples of differing limits but I can't remember them off the top of my head)

Leaky Nun

@Sp3000 no, the limit is still not its value

Poke

@Maltysen I'm not sure about this

Leaky Nun

@Poke that is true in convention

Poke

@LeakyNun Because of the binomial formula

Leaky Nun

2:31 PM

@Poke cite it and point out where 0^0=1 is useful

Nathan Merrill

I think that because 0^0 is undefined, ^ is undefined

its a broken operator

lets stop using it

Leaky Nun

@NathanMerrill what the hell?

Nathan Merrill

Oh, should I have added a ":P"?

clearly 3*x*x*x*x*x is clearer

Maltysen

I think you meant that 0 is broken, let's stop using it

Nathan Merrill

oooh, maybe, yeah

Maltysen

2:33 PM

It breaks all the operators :/

Business Cat

0! doesn't really work either

Leaky Nun

@BusinessCat 0! is defined as 1

Business Cat

I know

Nathan Merrill

we need to come up with another symbol for 10

Leaky Nun

@BusinessCat Then what do you mean by "doesn't really work"?

@NathanMerrill bijective base

Nathan Merrill

2:35 PM

we could use A, but that's confusing with the letter A

Poke

@LeakyNun It's not that 0^0 is strictly useful but everywhere I've read about the binomial formula (x+y)^0 is supposed to be substituted by 1. Here's an example and wikipedia likely has something similar. I don't have time to find a better source at the moment

Business Cat

Because n! is the product of all positive integers up to and including n

And 0 isn't positive

Leaky Nun

@BusinessCat that's why 0! is specially defined to be 1

Business Cat

Right, it's specially defined because it doesn't have an intuitive answer

Maltysen

@BusinessCat but the actual technical definition is 0!=1, n!=n*n-1!

FryAmTheEggman

2:36 PM

@BusinessCat You could instead think of it as the number of possible orderings of a set of size n, where the 0 case makes sense.

Maltysen

@BusinessCat 1 is the intuitive answer

Leaky Nun

@Poke I see, thanks

Nathan Merrill

anyways, assuming we could use A, I think numbering would look like 1,2,3,4,5,6,7,8,9,A,A1,A2..A9,2A..9A9..AA

hmmm, not sure if that would work

no, I think it will

Poke

@LeakyNun I spent a little more time. Here's a better reference. Take a look at page 162

Leaky Nun

Bijective numeration

Bijective numeration is any numeral system in which every non-negative integer can be represented in exactly one way using a finite string of digits. The name derives from this bijection (one-to-one correspondence) between the set of non-negative integers and the set of finite strings using a finite set of symbols (the "digits"). Most ordinary numeral systems, such as the common decimal system, are not bijective because more than one string of digits can represent the same positive integer. In particular, adding leading zeroes does not change the value represented, so "1", "01" and "001" al...

Nathan Merrill

2:38 PM

we can't use Bijective, because it has a representation for 0

Leaky Nun

@NathanMerrill no, 0 is empty string in bijective

Nathan Merrill

...that's a representation

Maltysen

@LeakyNun he wants to have no 0

Leaky Nun

then just remove it from the definition

@Poke Just looked. I don't agree with the book

I just discovered that logical OR is and/or in English

and XOR is or in English

as in you may do this and/or this, which corresponds to the logical OR

TimmyD

I wonder what Game of Life pattern wolframalpha.com uses for it's "Calculating..." placeholder

Maltysen

2:44 PM

@LeakyNun but even that's not consistent. Natural languages suck :/

Leaky Nun

@Maltysen for example?

Poke

@LeakyNun fair enough.

Sp3000

@Poke I think it's more a matter of context here - since polynomials deal with x^0 a lot, it's more useful as a definition to define x^0 = 1 here for x = 0

Maltysen

@LeakyNun no specific examples, just that people sometimes use or as logical or and sometimes not

Poke

Sure but generally I would think mathematics is against situational equivalence

zyabin101

2:46 PM

Mom gave me her phone back ☺

Hewwo :D

My first saved paste on codepad

Leaky Nun

0

Q: Print/Output all positive numbers in which every multi-digit substring in its decimal representation is also prime.

Task Your task is to print or output all positive numbers in which every multi-digit substring in its decimal representation is also prime. If the number has at least 2 digits, this would imply that the number itself also needs to be prime. Example 6197 is in the sequence because every multi-...

New Main Posts

@NewMetaPosts THEY TOOK ER JURBS

5

TimmyD

@LeakyNun 1 isn't prime, though ...

Poke

New Main Posts proving yet again that it waits until someone posts their own challenge before posting it.

Sp3000

@Poke I think it's just what happens when something is not well defined and we try to attach a definition to it - e.g. when we cancel 2x/x = 2 in algebra, technically we're ignoring for a brief moment the fact that x could be 0, but then the question is whether it really matters for the end result

Leaky Nun

3:00 PM

> 8 is also in the sequence because every multi-digit substring in 8 is prime. There is no multi-digit substring in 8, so this is a case of vacuous truth.

TimmyD

Ah, missed the multi-digit requirement

Poke

@Sp3000 I understand your point of view but I'm not sure your example illustrates your point. I don't even know the original context of the debate; just adding a little tidbit

Eᴀsᴛᴇʀʟʏ Iʀᴋ

@LeakyNun mod abuse 11 pls

Business Cat

Is it OK to add a leaderboard snippet to someone else's challenge, or should I just ask them to do it?

Sp3000

@Poke No worries, tired - think I'll just drop it :) Thanks for making me think about it though

βετѧ Λєҫαγ

3:10 PM

@BusinessCat Ask them to do it

zyabin101

Second paste in the "Hello, What's Your Name?" series.

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

Program a Speed Camera code-golf image-processing Introduction You're working on a government programming team, who have been programming the speed cameras. However, the group of people who have programmed the speed calculator have taken up too much space, so you have to make the number plate ...

Business Cat

Good thing I have this open in a different window

I accidentally made an infinite loop in JSFiddle with alerts

RIP

Releasing Helium Nuclei

codepad.org/xh07vVEi

codepad.org/U5rnAbCq

preprocessor abuse

not abuse but... whatever

ven

if there's preprocessor, there's abuse.

drobilc

3:21 PM

is there a limit on how many macros you can define?

βετѧ Λєҫαγ

Depends on the memory space of your computer

Releasing Helium Nuclei

> Number of macros simultaneously defined in a single translation unit.
> The standard requires at least 4095 be possible. CPP is limited only by available memory.

drobilc

could you do something like #define \n \n;?

ven

no

βετѧ Λєҫαγ

Why would you want to?

ven

3:24 PM

because he's a badlet

quartata

@drobilc No, the definition name has to be a valid identifier

Anonymous

3:40 PM

Google interview in ~2 hours... The nervousness has no end.

TimmyD

@Mego Didn't @NathanMerrill get a job at Google?

Nathan Merrill

er, I got an offer, but didn't end up accepting it

@Mego good luck. Mine was pretty enjoyable

Anonymous

I'm stressing because that's what penguins do

Nathan Merrill

I really liked my lunch. Not the food as much as simply being able to talk with a google developer casually

Anonymous

I'm on the first stage (phone interview) of the interview process

Anonymous

3:51 PM

I'm not actually at a Google campus right now :P

Nathan Merrill

oh, if that's the same as mine, its basically a follow up to your resume.

they didn't ask me any technical questions

Anonymous

No, this is a technical phone interview

Anonymous

I had the "casual talk with a recruiter" part 2 weeks ago

Theo

At least you got this far...

Nathan Merrill

@Mego huh, that's different than my experience. You are in the US, right? Did they offer to fly you out?

Leaky Nun

4:12 PM

@Mego English is actually infix because the operator (verb) is in the middle of the S-V-O structure

I will give +300 bounty to anyone except @Fatalize who submits the smallest answer to this challenge in Brachylog (wiki link) (TIO link). — Leaky Nun 1 min ago

Nathan Merrill

also, whoever convinced me that git submodule update would work, it totally doesn't

it doesn't actually pull the latest changes

and I have to manually do a git pull in each submodule

(or a git submodule foreach)

quartata

Should be able to do git submodule update to pull the latest from all of them

Nathan Merrill

nope

oooh, there is a "git submodule update --remote --merge"

TimmyD

@NathanMerrill Oh. I didn't mean to presume.

Nathan Merrill

no, you're fine

the news of a google offer spreads faster than news of a google decline :)

Maltysen

4:27 PM

@Mego which campus?

(if you get an offer)

@drobilc genius idea, but idk if it'll work

Rohan Jhunjhunwala

@quartata be sure to golf down the questiosns they give you

@LeakyNun what challenge?

Leaky Nun

4

Q: Print/Output all positive numbers in which every multi-digit substring in its decimal representation is also prime.

Task Your task is to print or output all positive numbers in which every multi-digit substring in its decimal representation is also prime. If the number has at least 2 digits, this would imply that the number itself also needs to be prime. Example 6197 is in the sequence because every multi-...

code-golf string kolmogorov-complexity sequence primes

Rohan Jhunjhunwala

is there a minimum requirement for the quality of my contending answer

mınxomaτ

@RohanJhunjhunwala surprisingly relevant.

3

ven

@aditsu thanks. The current language lives on github, example here. CJam not yet included as I'm not sure yet how to have it read all of stdin :)

Anonymous

4:41 PM

@Maltysen Austin

Anonymous

So I just had my phone interview, 2 hours early

Anonymous

The engineer read 11 am on the schedule, but missed that it said Pacific time :P

Rohan Jhunjhunwala

@mınxomaτ I wonder how quickly you would get fired for golfing production code?

Anonymous

So now I don't have to stress out for the extra hour that I was going to

aditsu

@ven not sure what kind of example is that :p to read all of stdin in CJam, you use q

uoɥʇʎPʎzɐɹC

4:47 PM

@RohanJhunjhunwala huh?

Leaky Nun

@RohanJhunjhunwala no?

βετѧ Λєҫαγ

Hey guys, any thoughts:

0

A: Sandbox for Proposed Challenges

Program a Speed Camera code-golf image-processing Introduction You're working on a government programming team, who have been programming the speed cameras. However, the group of people who have programmed the speed calculator have taken up too much space, so you have to make the number plate ...

Anonymous

@RohanJhunjhunwala Make a serious effort towards optimizing for the winning criteria is the only requirement

Rohan Jhunjhunwala

seems hard @βετѧΛєҫαγ

@Mego ok, I have no shot at that Brachylog confusees me too much.

@Mego how did your interview go?

βετѧ Λєҫαγ

@RohanJhunjhunwala That's why it's called a challenge

Rohan Jhunjhunwala

4:52 PM

most "challenges" on this sight that make HNQ aren't challenges :(

βετѧ Λєҫαγ

Yeah.. :P

Rohan Jhunjhunwala

@βετѧΛєҫαγ it's a good challenge, but may be a bit high of a difficulty level for code golf

You may have limiited participation

Anonymous

@RohanJhunjhunwala Very well. None of the questions were very difficult.

Leaky Nun

@RohanJhunjhunwala you only need to show that you have tried to golf; also, I posted quite a handful of resources for you

Rohan Jhunjhunwala

@Mego nice!

βετѧ Λєҫαγ

4:54 PM

Neat, 1111 answers

Rohan Jhunjhunwala

@Leaky Nun it is incredibly confusing. :(

Anonymous

Now I'm going to celebrate the interview going well by playing video games poorly

Business Cat

Good idea

Leaky Nun

@RohanJhunjhunwala I also posted a chatroom in which Fatalize logical-or I will answer your questions

Rohan Jhunjhunwala

is BrachyLog turing complete?

Leaky Nun

4:56 PM

@RohanJhunjhunwala yes, it is not those languages where you have to build operators with a lot of effort

Rohan Jhunjhunwala

ok my bad

βετѧ Λєҫαγ

@RohanJhunjhunwala BTW I wouldn't say it's too hard considering that each character is always going to be the same. It's mainly a matter of shape matching

Leaky Nun

@RohanJhunjhunwala I accidentally pressed my caps lock lol

Rohan Jhunjhunwala

oh I thought u were mad

@βετѧΛєҫαγ yeah, it seems like quite an interesting challenge

Maltysen

@Mego any fun questions?

Rohan Jhunjhunwala

4:57 PM

Unless people abuse mathematica, the scores will be incredibly high

(in bytes)

@Mego are you allowed to talk about the questions? Or is Google strict about releasing them?

Maltysen

@RohanJhunjhunwala my dad talks about his pretty freely, but idk, also hes the interviewer, not the interviewee

Leaky Nun

@RohanJhunjhunwala Are you doing it?

Maltysen

@RohanJhunjhunwala which challenge?

Rohan Jhunjhunwala

@Leaky Nun I can look into the challenge, but The best I might do would be a hardcoded list. I feel like that could be an insult, I do not know if my golfing attempt will be of a respectable quality.

Dennis

Fedora 24 comes without Python 2. o_O

Rohan Jhunjhunwala

5:01 PM

o_O

Leaky Nun

@RohanJhunjhunwala try to learn the language?

Rohan Jhunjhunwala

:D

βετѧ Λєҫαγ

1

A: Sandbox for Proposed Challenges

Program a Speed Camera code-golf image-processing Introduction You're working on a government programming team, who have been programming the speed cameras. However, the group of people who have programmed the speed calculator have taken up too much space, so you have to make the number plate ...

Maltysen

@Dennis but with python 3, right? :P

Dennis

Of course.

Rohan Jhunjhunwala

5:02 PM

@LeakNun I will. Wish me luck

i just don't wish to offend you with the poorly golfed output.

Maltysen

@Dennis wait are u serious, the default is python 3?

Dennis

Yes.

$ python
-bash: python: command not found

Nathan Merrill

finally!

Maltysen

Awesome!

@canonical plz do dis also

Dennis

Python 2 is great for code golf, but why somebody would still use it irl is quite frankly beyond me.

Leaky Nun

5:05 PM

@RohanJhunjhunwala I am hardly offended by anything here

I just don't invest my emotion on this site

Nathan Merrill

@Dennis libraries

but I agree

Rohan Jhunjhunwala

@LeakyNun ok, I will attempt to submit a brachylog submission

Leaky Nun

@RohanJhunjhunwala don't hard code the list

Rohan Jhunjhunwala

I just still can't figure out how to output

I wont

I will try to compress it

Leaky Nun

@RohanJhunjhunwala you can ask us questions in the chatroom

Brachylog

Discussions about the Brachylog language. github.com/JCumin/Br...

I will answer you

Maltysen

5:07 PM

@Dennis appengine :/

Rohan Jhunjhunwala

@LeakyNun thanks!

Maltysen

Wait the license plate images will be exactly the ones on the post, right?

quartata

@Dennis Does RHEL still use 2.x kernels

Maltysen

Then just cut them up and look the char up with the hash of the image

βετѧ Λєҫαγ

@Maltysen Yeah, you could do that

Dennis

5:10 PM

@quartata No clue. Fedora 24 uses 4.5.5.

Maltysen

And it's monospace, right?

quartata

@Dennis Oh, wow.

βετѧ Λєҫαγ

@Maltysen I'm fairly sure it is

Can't be sure though

ven

@aditsu the first line on each line determines which language will be used to run it. y for Jelly. N for perl6, p for pyth, etc.

@aditsu I'd like to read every line as a different stack argument though?

aditsu

first line on each line?

Poke

5:12 PM

For anyone who was part of our 0^0 discussion earlier: IEEE Standard

aditsu

@ven qN/~

Leaky Nun

@Poke Sure, some fields require 0^0 to be 1

Poke

just adding some more info

βετѧ Λєҫαγ

Hey @Dennis, there's a plate for you... kind of

click4reg.co.uk/private-number-plates/DEN15

Poke

it mentions pow and powr

Maltysen

5:17 PM

@βετѧΛєҫαγ oh wait the space char is of a different size than the others, I think

Dennis

@βετѧΛєҫαγ I doubt I could it here (or would want to in an English speaking country).

zyabin101

Third paste in the "Hello, What's Your Name?" series.

βετѧ Λєҫαγ

@zyabin101 What are these pastes for?

zyabin101

@βετѧΛєҫαγ I'm trying Codepad. :3

ven

@aditsu alright :) I'll probably have 2 different "cjam" then. One that does this, the other with just q.

Thanks!

βετѧ Λєҫαγ

5:25 PM

@zyabin101 I see

zyabin101

I might end up making a code golf project page. :D

One question, I need a few people to actively participate in it.

Et I'm probably not going to.

Hai @ReleasingHeliumNuclei

Releasing Helium Nuclei

O hai @zyabin101

New Main Posts

3

Q: Identify a string from its substrings

Introduction I've previously created two challenges where the idea is to reconstruct an object using as few query-type operations as possible; this will be the third. The task Your inputs shall be a non-empty string S over the alphabet abc and its length, and your output shall be S. With no re...

string code-challenge

Releasing Helium Nuclei

@zyabin101 i don't know latin what does et mean /s

zyabin101

@ReleasingHeliumNuclei And.

Releasing Helium Nuclei

5:34 PM

@zyabin101 i was...joking.../s means im being sarcastic...

zyabin101

IKR!!

Releasing Helium Nuclei

Den y u answur srsly i dun undrstan

Eᴀsᴛᴇʀʟʏ Iʀᴋ

@zyabin101 i wouldn't mind, depends on how many other people want to

if nobody else then nah

Sherlock9

Alright I've deleted all my old Sandbox posts that I'm unlikely to finish or are unlikely to get polished into a decent challenge. Apollonian gaskets, extending the 24 game and the Beta Function went out the window.

zyabin101

@EᴀsᴛᴇʀʟʏIʀᴋ Okay, so I can survey people on the code golf project page idea.

βετѧ Λєҫαγ

5:42 PM

@ReleasingHeliumNuclei Eheu

Sherlock9

At some point, I should finish up that Capsa KotH, though

zyabin101

@Sherlock9 D:

Uh oh!

Sherlock9

Why? I deleted them intentionally