Re: fibonacci series what Iam is missing ?

Date	2015-03-23 20:42 -0400
From	Dave Angel <davea@davea.name>
Subject	Re: fibonacci series what Iam is missing ?
References	<CACT3xuVF-MOVQK5wSorRSAfpAQEXvS7QsqarACVZKXsQ0bxzpQ@mail.gmail.com> <mailman.72.1427127417.10327.python-list@python.org> <5510ad7a$0$12979$c3e8da3$5496439d@news.astraweb.com>
Newsgroups	comp.lang.python
Message-ID	<mailman.89.1427157732.10327.python-list@python.org> (permalink)

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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@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

Thread

Re: fibonacci series what Iam is missing ? Chris Angelico <rosuav@gmail.com> - 2015-03-24 03:16 +1100
  Re: fibonacci series what Iam is missing ? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-03-24 11:19 +1100
    Re: fibonacci series what Iam is missing ? Dave Angel <davea@davea.name> - 2015-03-23 20:42 -0400
    Re: fibonacci series what Iam is missing ? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-03-24 11:56 +1100
    Re: fibonacci series what Iam is missing ? Chris Angelico <rosuav@gmail.com> - 2015-03-24 11:59 +1100
      Re: fibonacci series what Iam is missing ? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-03-24 12:52 +1100
        Re: fibonacci series what Iam is missing ? Rustom Mody <rustompmody@gmail.com> - 2015-03-23 19:23 -0700
        Re: fibonacci series what Iam is missing ? Chris Angelico <rosuav@gmail.com> - 2015-03-24 14:03 +1100
          Re: fibonacci series what Iam is missing ? Rustom Mody <rustompmody@gmail.com> - 2015-03-23 20:30 -0700
          Re: fibonacci series what Iam is missing ? Rustom Mody <rustompmody@gmail.com> - 2015-03-23 21:13 -0700

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