fibonacci series what Iam is missing ?

[Dave Angel]

On 03/23/2015 08:19 PM, Steven D'Aprano wrote:
> On Tue, 24 Mar 2015 03:16 am, Chris Angelico wrote about the standard
> recursive version of the Fibonacci series:
>
>> On Tue, Mar 24, 2015 at 3:01 AM, Ganesh Pal <ganesh1pal at gmail.com> wrote:
>
>>> def fib(n):
>>>      if n == 0:
>>>          return 0
>>>      elif n == 1:
>>>          return 1
>>>      else:
>>>          return fib(n-1) + fib(n-2)
>
>
>> 2) Your algorithm is about as hopelessly inefficient as it could
>> possibly be, barring deliberate intent.
>
>
> It is pretty inefficient, but it is a good toy example of recursion. It's
> also a good example of how *not* to write the Fibonacci series in practice,
> what is mathematically straightforward is not always computationally
> efficient.
>
> The question is, just how inefficient is is? How many calls to `fib` are
> made in calling fib(n)?
>
> Answer to follow.
>
>
>

0 1
1 1
2 3
3 5
4 9
5 15
6 25
7 41
8 67
9 109
10 177
11 287
12 465
13 753
14 1219



-- 
DaveA