really clever

The input array will always be valid! (odd-length >= 3)

The solution seems simpler and i was wondering why it isn't voted as a best practice. Your comment made light. Thank you.
Sorting increases execution time. Even for a 7 element array.

exactly

Sort is overkill here. IMO too much upvotes.

Yes it is

Yup, that's the math way to do it.

Hello, thank you for your answer.

I just saw the example tests:

names1 = ["Sheldon", "Leonard", "Penny", "Rajesh", "Howard"]
r1 = 1
res1 = "Sheldon"
names2 = ["Sheldon", "Leonard", "Penny", "Rajesh", "Howard"]
r2 = 6
res2 = "Howard"
names3 = ["Sheldon", "Leonard", "Penny", "Rajesh", "Howard"]
r3 = 10
res3 = "Penny"
Test.assertEquals(whoIsNext(names1, r1), res1)
Test.assertEquals(whoIsNext(names2, r2), res2)
Test.assertEquals(whoIsNext(names3, r3), res3)

Your ruby and java version have r=6 , res=Sheldon indeed, maybe it's a cache thing or something because it has been a while since I've tried to solve it.

I see a test where r=6 and the answer is Sheldon, as expected. Not sure where you are seeing what you are seeing. I solved in JavaScript, maybe there is an error in a different language.

In descritption we see:
"The input data consist of an array which contains five names, and single integer n.
(1 ≤ n ≤ 1 000 000 000)."
But in output/examples we must receive "Leonard" for n == 7 230 702 951.
How can it be possible?