Why is my recursive function so slow in R?

Question

The following takes about 30 seconds to run whereas I would expect it to be nearly instant. Is there a problem with my code?

x <- fibonacci(35);

fibonac         


        

Answer 1

Because you are using one of the worst algorithms in the world!

Complexity of which is O(fibonacci(n)) = O((golden ratio)^n) and golden ratio is 1.6180339887498948482…