N делят на два , пока n не станет равной 1 или меньше, рекурсия рулит)

Рекурсия решает)

как. это. блядь. работает?!

ok, I'm just not very smart

If you talk about sample tests in javascript, as the comment says, you have to write them yourself:

// Create your own tests here. These are some of the methods available:
...

If you don't want to, just click Attempt

hmmm... why the tests doesn't work?