...looks pretty though

Went into comments just to say that, thanks dude for doing the work for me.

that's normal initialisation of variables, the data type doesn't matter
makes the code more compact

modulo operation correct?
If what you mean is how it works, in here it prevents Index out of range by taking the leftover of a division.
So by having the length of the original list when the number goes higher it instead loops arround to 0 every multiple of it.

Sorry for being dumb. can someone please explain how is the modulo operation correct?
Thanks

is it best practice to assign variables like this, when i and ys are different data types? I guess I can get used to it but it was confusing to look at at first.

i found solution, tks bro!

Print the input (hoping you are not modifying it) and the expected solution to debug.

it's strictly kata, i passed 45 and 5 fails, i dont know where wrong

okay thank you

It is not, read my answer there. And when posting code like that, it should be marked as having spoiler content (I wasn't the one who marked it, but I'd do it if you didn't).

oops

I guess unshift has to move all the elements one position and then you have a nested loop there. Not sure, but very likely.