Comment by numpad0
2 days ago
this doesn't need if statement but 3 variables: nm2 = 0; nm1 = 1; n; f_next(){n = nm1 + nm2; nm2 = nm1; nm1 = n;}
Fibonacci sequence is defined as "F0 = 0, F1 = 1, Fn = F(n-1) + F(n-2)". The author implemented F1 as a special case but it doesn't need to be. That's the weird part.
It's even more fun when you extend it to negative integers, reals, and the complex plane!
Matt Parker (Stand-up Maths) delves into this in a very approachable manner: https://www.youtube.com/watch?v=ghxQA3vvhsk