Comment by P-ala-din

I feel like these are poor choices.

* linked lists shouldn't be used anyway. and if they are used, you should use the standard implementation

* directly applying fibbonacci is trivial.

* sort: This is just a memorisation task, what's the point? (99% of the time, you shouldn't implement your own sort)

although, I agree with the open-book approach in the problem solving part.