Please Help Explain

[Stan Graves]

"Jakle" <jakle1 at hotmail.com> wrote in message news:<lIjqb.2510$gn1.317177 at news1.news.adelphia.net>...
> +++++++++++++++++++++++++++++++++++++++
> #   penny.py    11-05-03
> 
> days = raw_input("How many days: ")
> 
> def calc(n, days):
>     i = 1
>     while i <= days:
>         n = n*2
>         i = i+1
>     return n/float(100)

Technically, the return should be:
      
      return (n-1)/float(100)

The point is to sum the total, and your method over estimates the sum
by 1.  You can verify this by running the program for 2 days and
looking at the total.

If the pay is one penny on the first day, and two pennies on the
second day - the the sum at the end of two days is 3 cents...not four
cents as suggested by the above code.

--Stan Graves
stan at SoundInMotionDJ.com
http://www.SoundInMotionDJ.com

> 
> print calc(1, int(days))
> +++++++++++++++++++++++++++++++++++++++