The Nineteenth Byte

user

00:06

National Honors Society

Just another useless thing to put on your college application to look good

@NewPosts Weird, why is the meta question tagged completed?

DialFrost

01:35

Sup guys

caird coinheringaahing

02:27

@user ¯\_(ツ)_/¯ status-review posts are put into the CM notification board, so they'll see that it isn't status-completed any more

Radvylf Programs

03:06

I saw a fun looking math problem in a youtube thumbnail and spent 45 minutes doing it :|

But I now know the areas of the individual parts of the deathly hallows symbol :p

DialFrost

04:37

Me listening to the same song 5 days in a row on repeat

mathcat

08:22

@RadvylfPrograms waaaait

link pls

harry potter + maths = heaven

PyGamer0

08:38

@mathcat ∴ heaven - maths = harry potter

∴ heaven consists of harry potter!

mathcat

hmm right

mathcat

12:59

CMQ: What's harder? Finding bugs or killing bugs?

ophact

The former

Bgil Midol

finding bugs

PyGamer0

^

killing them is quite easy, i just smash them with a newspaper

mathcat

uff

ophact

@PyGamer0 Never works for me :(

PyGamer0

13:14

> did you mean: woof!

ophact

nope, because they are a cat

PyGamer0

godbolt.org is very cool

mathcat

meow

DialFrost

13:56

I plan to get 10k rep by end of june on ELL

Prob over ambitious tho

And assuming that i dont lose interest

ophact

14:06

You haven't posted in a month...

that's quite sad

We enjoyed your challenges

lyxal

14:19

@mathcat definitely finding.

mathcat

Y'all have bad eyesight.

lyxal

Once found, it's just a matter of redirecting all other processes towards the complete and utter destruction of the bug

We are talking about physical bugs right?

Because if we are then I just want to make it known that bugs are about 2nd on the list of animal species I extremely dislike

pxeger

"bug" is not a single species

lyxal

That doesn't matter.

Every species of bug is #2 on my list of disliked animals

pxeger

There are about 80000 Hemiptera

What's #1 then?

lyxal

14:22

Birds.

Can't stand the little punks.

Standing there arrogantly, mocking you and reminding you of the terrible things they do like poop on car, steal chip and make excessively loud noise

Jan 5 at 12:52, by lyxal

I swear birds have gotten away with corrupting the justice system - they get away with things like property damage, aggravated assault, theft, jaywalking and being a public nuisance yet they never get arrested nor do they get sentenced/fined in court.

ophact

Yet birds get all the bread.

graffe

Hello all!

Is there an easy to read description of how to solve sudoku quickly in code?

mathcat

14:42

so like not a video?

graffe

A video would be fine if that exists

mathcat

hmm

graffe

Maybe github.com/mstdokumaci/sudokumaci is enough

mathcat

I think techwithtim made a sudoku solver video

graffe

Cool

lyxal

14:50

@ophact for a moment I thought your chat bio said "JavaScript's chocolate" and I got really confused why you were claiming to be browser-executed cocoa

graffe

@mathcat thanks

mathcat

pt. 1 and pt. 2

ophact

@lyxal To be fair, JavaScript is scripting coffee, so JavaScript chocolate = cocoa coffee which isn't too weird

graffe

@mathcat "9^81 is a massive number that is probably in the trillions".....hmmm :)

ophact

mathcat fails at math again?

or rather sends links to wrong math

mathcat

14:55

wait wat

ophact

9^81 is over 10^65 trillions

mathcat

techwithtim? more like techwithmathsfailure

graffe

@mathcat :)

ophact

@mathcat Add it to your list of math failures in your profile

graffe

@ophact yep :)

mathcat

14:57

ah nice idea

graffe

Much larger than the number of particles in the universe

ophact

that's also wrong because there are at least 10^87 atoms (which are composed of several particles) in the observable universe

so definitely there are more than 10^87

particles

graffe

About 10^80 according to newscientist.com/lastword/….

So a little fewer than that you are right

ophact

Oh looks like I'm wrong then

but there are still more than 9^81 particles in the unvierse.

graffe

@ophact yes

Just not that many more

user

15:15

@graffe Here's a blog post about solving a miracle sudoku using Z3. You should be able to use it for normal sudokus too

There's quite a few articles about constraint satisfaction online if you're interested in that

Very cool topic

Also, Algorithm X looks cool (and not just because it's named X)

pxeger

@user I think Z3 is kinda overkill for sudoku lol

graffe

@user oh cool thanks

@user I am!

@pxeger ortools might be faster. I tried its cp-sat recently and it seemed faster than z3

pxeger

It will surely depend on the problem

Bgil Midol

^

graffe

@pxeger I am not sure. cp-sat is multithreaded where Z3 isn't to start with

There is a competition called minizinc that ortools seems to win

I wonder what happens if you make the sudoku puzzle really large

user

15:41

@pxeger I mean yeah, but doing a sudoku solver first isn't a bad way to learn about Z3 before using it for things that it isn't overkill for

@graffe Oh, interesting, I'd never heard of cp-sat before

Should try it

graffe

@user it seems very impressive but if you do try it please let me know. I am just learning how to use it

user

@graffe It'll depend on how the multithreading is implemented and your computer but I assume both of those are good

@graffe I'll be sure to do that

graffe

@user thanks

user

I'm just starting to get into constraint satisfaction despite wanting to for like two years now

graffe

@user I think ortools actually tries different heuristics in different threads where Z3 is just single threaded

@user cool

user

15:44

Oh interesting

So it's trying entirely different solvers in those threads instead of just different paths or whatever?

graffe

If they use SAT solvers they don't seem to use multithreaded ones

@user yes

pxeger

How long has this been a thing?

graffe

It's quite sobering to try maximum matching or maximum clique in these tools.

What you learn is that a smart algorithm is still infinitely better

pxeger

15:57

CMQ: How easily distinguishable (at small sizes) are the following characters for you? aȧä

caird coinheringaahing

@pxeger its been there for as long as I can remember

pxeger

Huh

graffe

16:54

is there any Python module that has Algorithm X implemented?

user

17:09

@pxeger Pretty distinguishable

graffe

I need to fill in time sheets for work. This just means a table with start time and end time for each day I worked. What's the easiest way to make a document with a table I can fill using code?

pxeger

plain text?

csv?

des54321

@pxeger distinguishable, as long as you dont get something like àá involved

user

You could maybe use Google Apps Script with Google Sheets, not that painful, but CSV is probably best ^^

des54321

17:30

in an attempt to help keep this chat on topic: heres a problem related to a current code golf I'm working on that I would appreciate insight on: is there a good way to compress a really long dict in python, knowing that the dict does contain a limited number of characters if stringified (basically just {}()",0-9A-Z)

user

You mean you want to serialize something like {"foo": 1}?

May I ask what the parentheses are for?

hyper-neutrino

do you know much about the keys? if the keys share a lot of prefixes you might be able to encode it into a trie, though in general i highly dount that'll be a save

user

What's the challenge btw?

Maybe there's a better strategy than hardcoding the dict? (I assume you're hardcoding a dictionary)

des54321

its Translate Text into Matoran

so my keys are all the ASCII letters in either uppercase or lowercase, and the values are tuples of tuples

user

Oh

des54321

17:38

{"A":((3,),(),1,()),"B":((1,3),(),1,()),"C":((2,),(),1,()),
  "D":((2,),(),1,(1,)),"E":((),(5,7),0,()),"F":((),(5,),0,()),
  "G":((),(1,9),0,()),"H":((1,3),(),1,(0,2)),"I":((),(1,),0,()),
  "J":((3,),(1,),0,()),"K":((),(4,9),1,(8,)),"L":((2,),(1,),0,()),
  "M":((),(0,2),0,()),"N":((),(1,),1,()),"O":((),(),0,()),
  "P":((1,),(1,),0,()),"Q":((2,),(),0,()),
  "R":((1,),(1,9),0,()),"S":((1,3),(),0,()),"T":((),(4,6),0,()),
  "U":((1,),(),1,()),"V":((1,),(1,6),1,()),
  "W":((0,2),(1,6),1,()),"X":((),(1,6),1,()),

this is what the full dict looks like

user

Perhaps you can use a list instead of a dict?

And then tuples like (3,) can become [3]?

And to get the letters you can just do chr

des54321

I am doing that in the actual version, I copied this out of an older, less golfed version thats actually formatted

My main thought is finding a better way to store the values, and then iterating over "ABCDEFGHIJKLMNOPQRSTUVWXYZ" to construct the dict

user

Oh ok

des54321

although that too might be hard

user

Is chr not golfy enough?

des54321

17:40

that might work honestly

like chr(i) for i in range(blah blah blah) where blah blah blah is the right range to get all uppercase ascii chars

user

I was thinking enumerate

des54321

I already have two uses of range in this program so that would let me golf that down to r and save some bytes

user

Ah

I like that Python just lets you do r=range

des54321

hmmm enumerate isnt actually a bad idea though, I had forgotten that function

python lets you do a lot of very stupid stuff

user

I mean, it's good for golfing

des54321

17:43

it certainly is

python conditionals are ridiculous

user

Much better than doing int r(int x){return range(x);}

lol yeah

But they're also kinda useful irl sometimes

Sometimes

des54321

you should actually take a look at the answer im golfing, theres a good show of some python ridiculousness in it

user

Looking at it rn

Love the abuse

des54321

yep

I think im using over half the possible 1-byte variable names in this

user

Btw, you use 60 multiple times. Perhaps you could use a variable for that too, defined with a walrus?

des54321

17:47

I'm pretty sure I calculated that that wouldnt save any bytes

user

Aww

des54321

IIRC I need to use a 2 digit int 5 times to save a byte walrusing it, and I only use 60 4 times

user

I think you'd only need to use it 4 times to save a byte

a:= adds 3 bytes and would take away a byte every time you use the number

des54321

but you dont take away a byte on the first use

user

Yeah

So you'd need to use it 4 times

des54321

17:49

use 1 becomes a:=60 so the others can become a

user

Wait nvm using it 4 times doesn't add bytes but it doesn't save either

des54321

4 times is the break-even point, because you add 3 bytes on the first use, and save 1 on each of the other 3

yep

so I could do it purely to make my code more unreadable, but that doesnt quite feel necessary

user

Yeah it's pretty unreadable already

des54321

I so wished I could have used the tuple fake ternary thing for the conditionals on the long line, but unfortunately I need shortcircuiting

one of the big problems with python golfing is no short ternary operator

Aaroneous Miller

Accurate description of Vyxalers

des54321

17:52

unless..... I can do some horrible bullshit involving strings and exec

hold on

I'm about to commit python sins

user

Oh dear

You've committed enough already

You can use a walrus for range(n%6) btw

Saves only 1 byte

Actually, I think that whole line could be turned into for i in range(a:=n%6):z=lambda r:(x+r*sin(a:=2*pi*i/a),x+r*cos(a));l(s,A,z(8+n//6*8),z(x))

des54321

my eval sins worked but were a good 10 bytes longer :(

@user oh good one!

UnboundLocalError: local variable 'a' referenced before assignment

user

Yeah just use b:=n%6 or something

And then use b in 2*pi*i/a

I just chose the first letter that came to mind

des54321

oh duh youre using two as

just gotta figure out which letters i can use here

hmmm somehow the output is upside-down now, time to poke into your math and see whats wrong

there we go, messed up sign

Radvylf Programs

18:36

@mathcat I didn't watch it, so no link

New Posts

18:57

0

Q: The Binary Eyes

A binary eye is a odd set of digits, with all of its digits except the center one set to 1 or 0, and the center one set to the opposite of the others. Thus, there are two binary eyes for a given odd number of digits: | x | eyes | | - | ---- | | 1 | 1,0| | 3 | 101,010 | | 5 | 11011,00100 | | 7 |...

code-golf

des54321

19:33

Is there a simple way to use the python base64 module to encode a really large int as a base64 or base85 string? I feel like that should be possible but I cant figure out exactly how

pxeger

I think you'd be better off writing your own encoder

des54321

ugh thats not useful for the golfing problem im trying to solve

pxeger

I think you'd be better off writing your own encoder

Actually, I forgot about the int.to_bytes method

although it requires an explicit length

des54321

oh perfect that should do the trick

now to figure out how many bytes i need

pxeger

len(bin(x)[2:])//8 is one way

If you don't mind extra leading zeroes, you can use the "safe" upper bound of n itself (but which doesn't work for n=0)

des54321

19:54

I ended up using half the length of the int in hexadecimal, which im pretty sure also works out right

I'm pretty sure this is the biggest abuse of python I've ever committed, and its probably not even as golfy as I'd like

T='1234567890(),'
D=lambda a,b:D(*divmod(a,13))+T[b] if a!=0 else T[b]
dict(zip(map(chr,range(65,91)),eval(D(*divmod(int.from_bytes(b85decode('1I4$AG^!ES_HeL)X2~Of79ExFC_6^uiLRYztX@6>+bEgKbEh;RB2T(R(*^>bw&yaOg|zb~s(~0+qW$y9Cvwq_q%!U+?tz=a|MWT);M~>WocxX3`Zi7N`JF4+wk4ezU3OB@oJNMRx3Z5;BKgQ=wVM9_=MoZDs#bA6B$9uY-A8GxL6Nh<@~b+p?Da}XU;dXf@;-=xOuB?6K=iUECy1017gR?QfD*skwpiNRCC8mE@E^}3n2ZX@oDBH'),"big"),13)))))

pxeger

What question is this for?

des54321

Translate Text into Matoran

wait no this is 61 characters shorter than the dict I'm using in that right now

abuse of python: complete

pxeger

@des54321 D=lambda a,b:(a*"1"and D(*divmod(a,13)))+T[b]

des54321

oh good one

hold on I think if I re-arrange T and recalculate the big b85 string I can golf more off by not needing the divmod call in the args of D

pxeger

I think you can probably get rid of dict(zip(map(chr,range(65,91)) if you convert from letters to alphabet integers in the lookup instead of while constructing the dict

des54321

20:00

oh good idea

i think this is what qualifies as pornographic code

pxeger

lol

The lookups in the arguments to L can be simplified to the following, by using a separate lookup for each argument instead of several tuples:

[[3],(1,3),[2],[2],I,I,I,(1,3),I,[3],I,[2],I,I,I,[2],[2],[1],(1,3),I,[1],[1],(1,3),I,I,I][p:=ord(t[i])-65],[I,I,I,I,(5,7),[5],(1,9),I,[1],[1],(4,9),[1],(0,2),[1],I,[1],I,(1,9),I,(4,6),I,(1,6),(1,6),(1,6),(1,9),[6]][p],[1,1,1,1,0,0,0,1,0,0,1,0,0,1,0,0,0,0,0,0,1,1,-1,1,1,1][p],{3:[1],7:(0,2),10:[8]}.get(p,I)

There's got to be a shorter way to do the [1,1,1,1,0,0,0,1,0,0,1,0,0,1,0,0,0,0,0,0,1,1,-1,1,1,1] bit

Also, ...,I=...,() can be changed to ...,*I=...

des54321

wow thank you for all of this, its gonna take me a sec to figure out how all of this works together in the actual code

im still working on getting the whole b85 translation working

pxeger

That assignment line can be shortened to

A,c,l,S,d,T,U,W,Y,*I="red",draw.circle,draw.line,Surface,display,(w:=16,4),(x:=32,0),(v:=48,60),(y:=64,y);V=w,60;Z=x,y;X=x,x

- you can remove some of the parentheses by using more than one =

des54321

@pxeger well thats gonna be made irrelevant by my terrifying base85 nonsense, because I is only used to golf down all the literal ()s in the hardcoded dict

Sandbox Posts

21:18

0

A: Sandbox for Proposed Challenges

Rotate a point code-golf Rotate a point on the coordinate plane. The formula for rotation(about the origin) is: $$(x,y)\mapsto(x',y')=(x\cos\theta-y\sin\theta,x\sin\theta+y\cos\theta)\,$$, where θ(I can't do inline math) is the angle, (x, y) is the starting point, and (x',y') is the rotated point...

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