Thanks!

;-)

You've basically got the correct solution. I think you are spending too much time on n % 2 == 0. Try to think of alternative ways of testing for odd or even. May-be precompute/get all the bits of n in one operation. A number is stored in binary, isn't it? No need to recompute the bits.

My solution calculates fusc(1 << 100000) in 18 ms. Your code is super inefficient.

Yeah, I know it's frustrating. I just ran my own solution and it completed in under 5s so I don't think you can only blame the server.

This is simplified version of the kata. Bruteforce should be enough to pass all the tests. Either optimize or find another approach. And yes, there are many approaches, as you can see in harder version of the kata.