yes, my problem was in modifying original array...
read comment about that (in the bottom) a little bit later then my post.
thanks

Are you all mutating the input?
@GiacomoSorbi wouldn't it be easier if you pass a copy of the array instead or get the expected value first?

I got the same issue in ruby :( I don`t know how the answer could be 0 in array of [1, 90] -____-

Ruby. Looks like first test works but the main test doesnt. As I said, the resonse is: Expected 0 instead got eg. 3459(number that you would get if you actually run the code)

@Kasia1946 Hi,Kasia... Well , What's the Language You Tried to solve the problem in ?? .. I'm tuned to know .. Regards ...Zizou

Hi, when its testing the code 2nd time, all the arrays return as expected: 0, why?