The Nineteenth Byte

In mathematics, especially order theory, a partially ordered set (also poset) formalizes and generalizes the intuitive concept of an ordering, sequencing, or arrangement of the elements of a set. A poset consists of a set together with a binary relation indicating that, for certain pairs of elements in the set, one of the elements precedes the other in the ordering. The word "partial" in the names "partial order" or "partially ordered set" is used as an indication that not every pair of elements need be comparable. That is, there may be pairs of elements for which neither element precedes the other...

ASCII-only

(so it's a set of <= instead of any comparison)

orlp

@LeakyNun I'm not used to analyzing this from that context

let's say I have two elements a and b

and I compare them with a <= b

and the result is false

ASCII-only

1:16 AM

then that's not a partial ordering

orlp

I now know a > b

I'm used to viewing this from the sorting perspective ^^

where you're counting comparisons

ASCII-only

@LeakyNun hang on

orlp's solution doesn't work since posets are reflexive right

Leaky Nun

right

I thought he just removed reflexivity, since they can be easily transformed to each other

ASCII-only

i guess that would work

this should work?

91

Leaky Nun

1:36 AM

@ASCII-only hint: count

ASCII-only

@LeakyNun ??? how can i use that

Leaky Nun

well, you would replace the any in orlp's code with C[r].count()>1

CMC: (extrapolate by yourself) given n=4, output [[0,1,1,1],[1,0,1,1],[1,1,0,1],[1,1,1,0]]

ASCII-only

@LeakyNun but it doesn't look like it would work here

Leaky Nun

well, there's nothing above r iff the count is 1

ASCII-only

@LeakyNun is this for orlp's code

Leaky Nun

1:42 AM

for you

ASCII-only

@LeakyNun python 2, 54

Leaky Nun

replace -- with +

ASCII-only

oops. actually 54

Leaky Nun

oh and I have a 49-byter

ASCII-only

@LeakyNun Charcoal, 8 bytes: ＥθＥθ¬⁼ιλ

Leaky Nun

1:46 AM

CMC: Given a partial ordering, extend to a total ordering.

ASCII-only

@LeakyNun would it be always possible though

orlp

@LeakyNun lambda n:[[1]*k+[0]+[1]*(n-k-1)for k in range(n)]

Leaky Nun

no idea

bingo

ASCII-only

>_> oh yeah. was going to do that but 1. more effort 2. i thought it would be longer. i guess a double loop is really ungolfy though

@LeakyNun so like this just with values flipped

Leaky Nun

right

@ASCII-only also 8 bytes: ＵＯθ1Ｇ↘θ0

ASCII-only

1:58 AM

@LeakyNun :O you can write charcoal. also i guess that works but it's not actually an array :P

Leaky Nun

oh

ASCII-only

imo text based output is only valid if there's no other choice. e.g. windows batch apparently

Neil

@orlp that 1/2**0 term dwarfs the others

@LeakyNun Charcoal, 8 bytes: Ｅθ⭆θ¬⁼ιλ

Leaky Nun

oh and my latest CMC is possible

19 mins ago, by Leaky Nun

CMC: Given a partial ordering, extend to a total ordering.

orlp

@LeakyNun fun fact

if you know the number of possible linear extensions of a partial order you can make an optimal sorting algorithm

because you can greedily select the comparison which results in the least amount of linear extensions

Leaky Nun

2:13 AM

I see

FreezePhoenix

3:18 AM

Hi

Pavel

5:52 AM

I just noticed something interesting.

tio.run/##Sy4o0E1PTv7/XzkzLzmnNCVVwaa4JCUzXy/… (GCC)

tio.run/##Sy4o0E3OScxL//… (Clang)

One complains the type is void* and the other complains it's nullptr_t

ASCII-only

8:12 AM

@Pavel makes sense though since nullptr implementation is up to the compiler I think?

(well, most of its behavior)

New Sandboxed Posts

8:47 AM

0

A: Sandbox for Proposed Challenges

Analyse elegiac couplets code-golf natural-language The elegiac couplet is a poetic form, consisting of a hexameter and a pentameter: \begin{align} -\overline{\smallsmile\smallsmile} |-\overline{\smallsmile\smallsmile} |-\overline{\smallsmile\smallsmile} |-\overline{\smallsmile\smallsmil...

Leaky Nun

9:57 AM

hi @orlp

orlp

@LeakyNun hi

orlp

11:13 AM

@LeakyNun I'm done with my exams

user202729

11:53 AM

@LeakyNun How can "a partial ordering" be represented anyway

A solution would be to try all permutations and test validity.

ngn

12:12 PM

@user202729 there are better solutions: en.wikipedia.org/wiki/Topological_sorting#Algorithms

user202729

@ngn Not for code golf...

mınxomaτ

12:33 PM

Pure evil: github.com/coleturner/pettier

Pavel

2:26 PM

@ASCII-only No, it's supposed to be nullptr_t. GCC is wrong.

HyperNeutrino

3:04 PM

is document.getElementsByClassName guaranteed to return the elements in order that they appear in the HTML?

user202729

3:35 PM

@Pavel It's just a warning...

Pavel

The warning is wrong.

user202729

Probably GCC decide to make a "reasonable" conversion first.

I don't know why.

Downgoat

6:31 PM

@HyperNeutrino yes dom.spec.whatwg.org/#concept-getelementsbyclassname

Mr. Xcoder

6:42 PM

Swift's OOP is just amazing for writing esolangs, but unfortunately the other so-called features such as its very strict type system are upsetting... (yes, I am attempting to write a stack-based language in Swift)

Downgoat

@Mr.Xcoder strict type system? O_o example?

Mr. Xcoder

@Downgoat pow() is the best example I have in mind right now

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

Rotational symmetry in which bases from 2 to 36 A number (here, a non-negative integer) is rotationally symmetric if it "looks" the same after being rotated 180 degrees. For example, 69 (heh.) Here's a related challenge. We're going to consider bases from 2 to 36, using the symbols 0-9A-Z as ...

Neil

7:07 PM

I spent all afternoon trying to work out how to write some nice plumbing from a C-style callback library to a C++ object. I managed to simplify it down to a template struct and a template function. I'd link some code but a TIO link won't fit in chat.

Mr. Xcoder

You can make it fit by using CTRL/CMD+ENTER

Erik the Outgolfer

7:32 PM

@orlp lol the example here is a very close call

mınxomaτ

10:16 PM

I have developed such a deep hatred for Docker...

Erik the Outgolfer

are you sure you didn't just type another string and then type "dreh"? also, use gitlab lol

mınxomaτ

Gitlab, the hosted service is absolute trash. The medium time to open a page for a smallish project from our office (two independent fiber connections) is 15 seconds. Hosted build don't work most of the time, because Gitlab.com's infrastructure is garbage (their metrics are public, frequent outages and queue overloads).

The load time for any page on their site that is!

Erik the Outgolfer

and I suspect GitHub is also too slow

mınxomaτ

No, of course not.

Erik the Outgolfer

(and to be acquired by Microsoft)

mınxomaτ

10:22 PM

GitHub is fine. Microsoft's VSTS (the real Gitlab competitor for "real" enterprises) is also pretty great. VSTS build system e.g. is awesome, comparable to e.g. Buildkite.

Erik the Outgolfer

I guess you can't ask for, eh, migration to GitHub, right?

mınxomaτ

Why would you do that? You'd loose pretty much all features of Gitlab/VSTS.

GitHub is a simple git frontend. Gitlab and VSTS are full cycle software project management tools (PM, helpdesk, ticketing, code hosting, merge workflow, build management, cluster management etc).

I love both of them. I hate Docker, though.

Erik the Outgolfer

so, why are you forced to use it?

mınxomaτ

Docker? What else are you going to use?

Oh, the error was / is a full service disruption: status.docker.com/pages/533c6539221ae15e3f000031 :(

Erik the Outgolfer

does this happen often?

and...Docker Status's Twitter account has been suspended

ouch

mınxomaτ

10:34 PM

There is always something wrong, and when you find it, the next thing breaks.

Docker is a Heisenbug accelerator.

I'm giving an in-depth hands-on Docker workshop tomorrow to a team of 30 devs. Hopefully, it'll be back by then I can skip half of it ...

Erik the Outgolfer

10:49 PM

> [Investigating] Our systems are experiencing higher than usual error rates due to a failure in our caching systems. Our team is investigating.

tip of advice: "a" can't replace "another"

mınxomaτ

> tip of advice

Where's the rest of the advice :D

Erik the Outgolfer

if I post it fully, it will be most likely considered noise, so the rest is implied :P

Conor O'Brien

CMC: Given an array of integers N (at least 1), output the number which is the concatenation of each integer in N. E.g.: N = [123, 491, 400], output 123491400.

Erik the Outgolfer

is this really not a dupe

Conor O'Brien

I'm pretty sure CMC's were just to waste time, not to be unique :P

Erik the Outgolfer

11:02 PM

@ConorO'Brien Convex, 0 bytes: Try it online!

Conor O'Brien

huh

neat!

Erik the Outgolfer

it's really just taking advantage of GolfScript's automatic procedure that can be described as 1) flattening the array 2) converting each element to a string (not representation, just string) 3) concatenating the strings together

so the solution is a full program :P

for example, [123 "abc" 400] is converted to:

123abc400

however, this is Convex, not GolfScript

well, it's simple: CJam is GolfScript's offspring, and Convex is CJam's offspring

some behaviors don't go away

FrownyFrog

@ConorO'Brien J, 8: [:;":&.>

Adám

@ConorO'Brien APL (Dyalog Unicode), 3 bytes ∊⍕¨

@ConorO'Brien Alternative J solution, 8 bytes ' '-.~":

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