The Nineteenth Byte

OldSandboxPosts

1:00 AM

Sandbox posts last active a week ago: Same number list shape?, Polyglot quiz

emanresu A

1:29 AM

tfw school wifi blocks stuff by using http

lyxal

2:58 AM

That moment when a math question asks you to prove a statement true, but you end up proving it false instead.

emanresu A

bruh

lyxal

the question is: show that there are no 3 prime numbers (p1, p2, p3) such that p2 = p1 + 2 and p3 = p2 + 2

and unless I'm mistaken 3, 5, 7 are 3 prime numbers where 5 = 3 + 2 and 7 = 5 + 2

emanresu A

lmao

That's the only case, but it's kinda funny

lyxal

lowkey wondering if it's a trick question or if they forgot to add a range of numbers or if there's a typo somewhere

or if they genuinely forgot 3, 5 and 7 exist

emanresu A

For full marks I'd suggest proving that there are no others but pointing that out as an edgecase

lyxal

3:06 AM

but if there's an edge case, that means that the statement is false overall

I'mma ask someone about it on wednesday

New Posts

3:51 AM

0

Q: A challenge for rookies

Print or return the following string: R******* *R****** **R***** ***R**** ****R*** *****R** ******R* *******R *....... .*...... ..*..... ...*.... ....*... .....*.. ......*. .......* *....... .*...... ..*..... ...*.... ....*... .....*.. ......*. .......* *....... .*...... ..*..... ...*.... ....*.....

graffe

5:17 AM

Just accepted an answer and now I feel I have done something bad

@lyxal there may be an infinite set of triples like that!

lyxal

2 hours ago, by emanresu A

That's the only case, but it's kinda funny

graffe

@lyxal I am so wrong

"one of every three sequential odd numbers is a multiple of three, and hence not prime (except for 3 itself)"

We can have the smallest and largest differ by 6 though in a prime triplet

Eg 881, 883, 887

There are also prime quintuplets

And "sexy prime quadruplets"

:)

thejonymyster

1:10 PM

was thinking of a challenge idea; sort of a pascal's triangle sort of situation, you're given a triangle of numbers and are asked to verify that each number (besides ones on the top row) are the sum of any two of the numbers above* them

*above is a little weird to define but basically like, any of what would be that number's "parents", not any of the ones that could never contribute to that number in a regular pascal triangle

more importantly though im just not sure whether it should be;

a) verify that this property holds for each number
b) verify that this property does *not* hold for *any* number

a) would mean that once youve found at least one eligible pair you can stop searching (probably) but b) is less edge casey since the top would have no eligible pairs no matter what

also with a) theres room to make the requirement stricter / potentially more interesting if this isnt cool enough lolol

Sandbox Posts

2:17 PM

0

A: Sandbox for Proposed Challenges

Program a parser compiler Write a program, function, or likewise that takes in a BNF-like grammar specification(see below) and outputs a program or function in a language of your choice that takes strings as input and returns truthy if that string is parseable with the specified grammar, and fals...

graffe

2:43 PM

Hello all!

user

Hello

GingerBot

Hi!

GingerBot

3:00 PM

oh boy a new Raspberry Pi kernel

Wheat Wizard

3:16 PM

Actually posting today in case anyone wants to feed me back:

2

A: Sandbox for Proposed Challenges

Polyglot quiz code-golfcops-and-robberspolyglot In this challenge as a cop you will choose two programming languages A and B, as well as a non-empty string S. You are then going to write 4 programs: A program which outputs exactly S when run in both A and B. A program which outputs S in A but n...

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