ReferenceError: Test is not defined
Looks like there a error in the Sample Tests. (JS Version)

Ok, someone already found not expected and better solution.
Going to put this kata on hold.

The main part of algorithm, it's hard to explain.
Perhaps changing the description (i has thinking about, " after the processing of ranges and etecetera").
Or just removing the commentary, but it's a helper. Yes is different N.

Well, i been thinking the same thing. Ok.

Done.

Done.

Done.

Ok, i forked your solution, i been working lately sorry for the later response!

I liked everything you did, but i needed to changed the basic tests and the description to make everything ok.

Now everything is done.

I think that the second value at last have some "Educational purposes", making people able to see if the Theorem is true or false given Mod M.
Even is not really the true challenge, but i prefer the question with this cherry in the cake.

Been thinking about a formula like this since when i created the questions.
Well finally i choosed to change it.

Thanks, and sorry the later response.

Yeah, that's is a issue. I changed the tests to do 300 iterations now, a little unstable but better.

I just overstated, now i added 10^4 tests too.
Removed "ranges from 1 to the length of the array." because of the existent biggers values.
And trying to guaranteed uniqueness in testing now, changed 0 ≤ cards.length ≤ 10^4 because of the new behavior of the tests, i know that will not effect any solution currently.

I don't know how big is this issue, but at this point is not that big, but at last some people can get in problems because of the uniqueness so correcting it is essential.

Well, perhaps i should remove this so.

I Added extra shuffle with the units tests, right now. And more intense random tests.

Done, 100 random tests.