The Nineteenth Byte

lyxal

00:39

@NoHaxJustRadvylf well in that case we need the feeds back for that while

I'mma add them temporarily until beep boops return - just for a few days at least

Feeds

lyxal has made a change to the feeds posted into this room

lyxal

gives us some time to build up butter reserves :p

Steffan

is it allowed in I/O if you're given a list to have an extra "EOF" at the end, like a 0?

Unrelated String

of course

NoHaxJustRadvylf

I'd guess no, but you might want to check the standard I/O

You could probably justify it as a trivial variation of null terminated strings

Unrelated String

00:47

^

Aiden Chow

@Steffan i think thats called a sentinel value, try searching for that

Unrelated String

although come to think of it it might be questionable if the length is already also encoded some other way it still seems reasonable

lyxal

@hyper-neutrino (or other mods) could we get the feeds renamed to New Posts and New Sandboxed Posts?

NoHaxJustRadvylf

Personally I think it depends on context tho. In a language like Python or JS, I'd consider that just a cheap trick to avoid a byte in certain contexts, whereas in something like C or some weird esolang it's more justifiable

(Personally I'm against there being standard I/O at all)

Aiden Chow

oh yep heres the standard i/o post on sentinel value: codegolf.meta.stackexchange.com/a/24639/96039

NoHaxJustRadvylf

00:49

@lyxal I'd do either "New Posts" and "Sandbox Posts" (to match the bots) or "New Main Posts" and "New Sandboxed Posts" (to match the old feeds)

lyxal

Sure, I wasn't fussed on the names, I was gonna leave that to the mod changing it lol

Unrelated String

fwiw taking length as a separate parameter regardless of if the language itself needs that is established practice but using sentinels without it being off stdin is actually preprocessing to some extent

so the meta post is probably the best thing to follow, strictly

Steffan

@NoHaxJustRadvylf I looked at the I/O rules but didn't really find much

@AidenChow oh ok thanks

but

> This can be applied to both inputs and outputs for languages such as C and assembly

is it still valid to do it in a normal lang where you could perfectly easily solve it without it :P

probably is

Aiden Chow

well it says langs such as C and assembly, not langs that are C and assembly :P

so its probably valid for any lang

if it isnt valid then i gotta change some of my piet answers lol

NoHaxJustRadvylf

@Steffan Technically yes, but it would likely be considered cheaty

lyxal

01:05

→ 5 duplicate grams of sugar moved to The Nineteenth Bakery

→ 5 duplicated tons of beans moved to The Nineteenth Bakery

lyxal

01:20

ah yes, the question is the answer

I really wish that photo was edited with inspect element

but it wasn't

Unrelated String

...what is this about

lyxal

it's a quiz to do with database management

Unrelated String

😔

New Posts

04:24

0

Q: Tips for golfing in Knight

Knight is the Language of the Month for August 2022, and I noticed that it didn't have a tips page, so here it is! I'm looking for ideas which can be applied to code-golf problems and which are also at least somewhat specific to Knight (e.g. "remove comments" is not an answer). Please post only o...

pxeger

06:39

What happened to the NP/SP bots?

Unrelated String

10 hours ago, by NoHaxJustRadvylf

NPSP is going to be down for a while, sorry. It seems that SE has made some major, possibly unintentional, changes to how some things work, and so I'm going to wait a little while to see if they get reverted, then it'll be a lengthy process to get everything working again if they don't.

Sandbox Posts

06:55

0

A: Sandbox for Proposed Challenges

Correct Quotations I noticed that in Microsoft Word, quotations are either ‘ or ’(double quotes: “ or ”), but not in Notepad. Your task today is: given a string q, convert all the ' characters (only) to ‘ or ’, according to these rules, and then output it: If the character before the quote is a ...

New Posts

13:35

0

Q: PUT-PIXEL in every language

During work on some project I need to be able to draw pixels on screen. I found some put-pixel function in JS but code was quite big and clumsy - so I wonder, how small put-pixel function can be... Challenge Create smallest put-pixel function. We count size of whole program: initialisation code (...

code-golf graphical-output

Nobody Needs Names

13:51

any ideas for this lang?: gist.github.com/TvoozMagnificent/…

promise will have explanation coming out... soon

mathcat

14:42

Any Lenova users here?

I might get one

It felt very maccy

graffe

15:09

@Adam if instead of getting no numbers between 0 and 0.1 you get 1, is the conditional probability that x=10 exactly 1/10?

user

15:25

@mathcat My parents have a Lenovo that's like 14 years old. It still works (okay, it's slow, but I think that's partly because it's got a 32-bit chip)

It probably depends a lot on the specific model you're looking at though

graffe

16:00

@mathcat what is your budget?

New Posts

0

Q: Help me golf this C program

I could not think of a better title. This is a tips question. I'm asking for tips on golfing my code. I recently took part in a code golf competition in C. The competition ended and I lost. The problem is: Input a line with a number n. Then input n lines, each line contains only a set of cards i...

code-golf tips c

Adam

16:17

Wait, I screwed up, ignore that

graffe

@Adam oh that's surprising! So just finding one number between 0 and 0.1 already makes it more likely that x=10?

Given that the prob is 1/10 before you start

Adam

I'm no statistician (I'm barely competent, honestly), so I might have messed up something simple, but that's what my results say

graffe

16:32

I am grateful nonetheless. I think there might be a mistake though

CMQ anyone good at prob able to check the above please?

I guess one simple check is to see if the probs add up to 1 if you sum for x=1...10

What do you get for each x?

Adam

@graffe I don't think that's correct

These probabilities aren't all coming from the same set of events, so they can't be compared like that

graffe

Aren't we computing the prob x=10 given that one number is in 0...0.1?

It has to be one of 1,2,....10

We could simulate and only look at the cases where there is one number in 0...0.1 to check

Adam

It's not hard to simulate, yeah

 k P(X=10|k nums. in [0,0.1])
 0 0.0595
 1 0.1280
 2 0.2163
 3 0.3097
 4 0.4057
 5 0.5032
 6 0.6017
 7 0.7007
 8 0.8002
 9 0.9000
10 1.0000

graffe

Exactly as you said!

What I meant was the prob x=k given that 1 number is found for each k=1...10

That is what should add to 1

@Adam thank you so much. Shows how bad my intuition is for probability

Adam

16:54

Actually, those are the theoretical calculations -- the simulation is still running

graffe

Aha :)

New Posts

0

Q: Implement String Projection

Given two strings: a string s and an alphabet a, implement string projection in the shortest code possible. String projection returns a string o that contains the characters in s that are in a. The order of the characters in o must match the order of characters in s. So if s = "abcd" and a = "12da34

code-golf string

graffe

I look forward to seeing the simulation results!

Sandbox Posts

0

A: Sandbox for Proposed Challenges

Write a program on any language that accepts some input and give some different output. The challenge is that the text of the program must form a square: all rows must be the same length and the number of rows must equal the number of columns (ie length of rows). Adding extra spaces or comments t...

0

A: Sandbox for Proposed Challenges

Write a program on any language that accepts some input and give some different output. The challenge is that the text of the program must form a square: all rows must be the same length and the number of rows must equal the number of columns (ie length of rows). Adding extra spaces, dead code, o...

graffe

I have invented a game based on this math problem

Adam

16:57

Preliminary results for 10,000 cases:
0 0.059830605025907264
1 0.12846799788415764
2 0.2159897994564184
3 0.31566020609749584
4 0.3999270871308786
5 0.5481727574750831
6 0.5882352941176471
7 1.0

graffe

That looks wrong for 7

Does it only see that case once?

Apart from that I would say it supports your math

Adam

@graffe I didn't keep track, but probably... that's the reason that the results are not intuitive, I think -- the situations where very few of the numbers are in the range [0,0.1] are way more likely than the situations where a lot of the numbers are

graffe

How about this for a challenge? I am not sure which tag it would get. x is chosen uniformly from 1..10 and x values from 0...1 are chosen. In the game you have two possible moves. The first is to
look in the next interval of size 0.1 and the second is to choose a new x and set of points and start back at the beginning.

The cost of looking in an interval between a and a+0.1 is (10 a)^2

The goal is to report when x=10 as cheaply as possible

@Adam does that make sense?

@Adam yes you are completely right

Adam

In the game, are you trying to generate new x's until x=10?

graffe

Yes. But you don't know if an x=10 for sure until you have checked all the intervals and that is expensive

Adam

17:11

Even if you've checked all the intervals, you can't be sure

graffe

Well you might know before that of course

@Adam why can't you be sure if you have checked all the intervals?

Adam

Oh wait, you're right, ignore that comment

graffe

I guess this is code-challenge

Adam

I think it's an interesting challenge, though I question the cost function

graffe

What would you prefer?

Adam

17:16

e.g. in that case, the cost of checking [0,0.1] is 0, so the ideal strategy is to just keep on generating new x's until there are 10 values in [0,0.1]

graffe

I guess the cost could double for each successive interval

1 for the first, 2 for the second, then 4 etc

Adam

This is almost entirely a statistics question, which isn't necessarily bad, but is definitely not usual

graffe

@Adam ah yes. That should cost 1

@Adam I think there are coding ways to attack these things. Reinforcement learning?

Adam

I don't think that would work

graffe

How come?

Adam

17:19

Well, I guess it could, but this is a simple problem, so it would be easy to find the mathematically optimal solution by hand and just implement that

graffe

If you set the goal as discovering x=10 and the reward as minus the new cost

@Adam that would be great but how?

Adam

Well, "easy" might not be the right word, but it's certainly tractable

graffe

I wouldn't know how to start

But I look forward to learning

Actually I have another maybe better related challenge

I will try to put it in the sandbox if I make my phone do that

Let me describe it here first :) if you are interested?

Adam

Sure

graffe

Consider four different symmetric random walks on the number line, all starting at the origin

You have one move which is to choose one of the four walks

When you do that an agent moves left or right by 1 with prob 1/2

If the agent is at 0 it always moves right

The goal is to get one agent to 10

The cost is the sum of the square of the number of moves (left or right) taken by all four agents

You want to minimise the expected cost

Is that clear?

Adam

17:37

I think so, yeah

By the way, the results for the simulation with 10,000,000,000 finished:

0 0.05949956402034444
1 0.1279909701638522
2 0.21632340766424374
3 0.30972599985531724
4 0.4055237027651227
5 0.504442913957367
6 0.6053614876607577
7 0.7062058130400628
8 0.8222222222222222
9 1.0

Sandbox Posts

0

A: Sandbox for Proposed Challenges

Optimal strategy for wandering robots Consider four agents sitting on four different number lines, all starting at the origin. In this game your input move is to choose one of the four agents to move. When you do that the agent you have chosen moves left or right by 1 with prob 1/2. If the agent ...

graffe

18:12

@Adam that's cool.I assume 9 only got one instance

Please do read and comment on my sandboxed question

NoHaxJustRadvylf

20:44

Tryna resist the urge to rewrite NP/SP in Rust

mousetail

@NoHaxJustRadvylf Stop resisting. Embrace oxidation

graffe

What is np/sp?

Zion mycelia adamancy

21:01

New Posts/Sandbox Posts, the bots that (normally) post new posts from main/meta/the sandbox into the chat room

NoHaxJustRadvylf

21:12

Node.js is weird about making it really easy to do some HTTP/network stuff with, and really hard to do other stuff

I had to write my own requests library from scratch to get it to handle cookies right

(Which I didn't do very well, and it's likely one of the things that's caused NP/SP to break without chatbot.py, which has the luxury of an actually good HTTP library, from doing the same)

I've been planning to rewrite NP/SP from scratch for more than a year now, but I can't work up the motivation to do it in Node (and whenever I can, the cookie RFC causes me too much physical pain to continue), so maybe Rust (or if there aren't sufficiently good libraries for HTTP stuff with cookies, maybe Python or Go or something) would be a good idea

Sandbox Posts

21:32

0

A: Sandbox for Proposed Challenges

Draw an N out of Ns given N Your challenge is to draw an ASCII art capital letter N that is n characters tall and wide, only using the capital letter N. The examples below should make it clear. Test cases n = 4 N N NN N N NN N N n = 5 N N NN N N N N N NN N N Rules: Trailing spaces ar...

Zion mycelia adamancy

@SandboxPosts I'm certain this is a dupe

Pretty sure there's a multipart challenge, with 3 parts, where the first one is to do that, but I can't find it :/

emanresu A

173

Q: Programming Languages Through The Years

In this challenge, users will take turns completeing three fairly simple coding tasks in programming languages that are allowed to be progressively older. The first answer must use a programming language that was made in the year 2015. Once there is at least one answer from a 2015 language, answ...

Zion mycelia adamancy

Ah, I thought it was one of Calvin's :P

Steffan

21:49

there is a difference that that is a popcon and the one in the sandbox is codegolf

emanresu A

True, and the sandbox one allows even sizes

Steffan

Looks like he deleted it

Zion mycelia adamancy

Yeah, they aren't the same, but tbh, I'm not entirely sure if the sandbox challenge is that interesting

We've had quite a lot of similar ascii-art challenges

Newly Featured Posts

23:18

23

Q: Backronymiser឵឵

Background A backronym is an acronym that was formed from an existing word. For example, spam is actually named after the canned meat product as used in the Monty Python sketch, but can be interpreted as "stupid pointless annoying mail". Challenge Given a string a, and a word t, capitalise the c...

code-golf string subsequence

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