How does it work?

Question

def fib(x):
if x==0 or x==1
return 1
else:
return fib(x-1)+fib(x-2)

print(fib(4))
print(fib(6))
print(fib(8))

>>>
5
13
34

Answer 1

Thanks.

Answer 2

Erfan Bazri

fib(4)

= fib(4 - 1) + fib(4 - 2)
= fib(3) + fib(2)
= fib(3 - 1) + fib(3 - 2) + fib(2 - 1) + fib(2 - 2)
= fib(2) + fib(1) + fib(1) + fib(0)
= fib(2 - 1) + fib(2 - 2) + 1 + 1 + 1
= fib(1) + fib(0) + 1 + 1 + 1
= 1 + 1 + 1 + 1 + 1
= 5