Oh, I have seen it, Modified my solution. thank you.

Hi, the input list mustn't be modified (see the explanation below). Regards, suic

Hi, the input list mustn't be modified (see the explation below.). I added it to the description. Regards, suic

Hi, the original version of kata is in Haskell which doesn't allow mutability by default. My translation mimics this behavior. I added the a note to the description.

Regards,

suic

I think the random tests are not working. I've passed the basic test easily, but the random tests array expect to multiply every second element by 4. Here is my error message:
the list second element: 2093
my returned list: [2827, 4186, -868, 2106, -1845, 1650, 2088, -1964, -1417, -3548, 2779, -2440, 1063, 3352, 1144, -4252, -2431, -3530]
should equal [2827, 8372, -868, 4212, -1845, 3300, 2088, -3928, -1417, -7096, 2779, -4880, 1063, 6704, 1144, -8504, -2431, -7060]