[Tutor] Can my code be optimized any further (speed-wise)?

[Alan Gauld]

Hi,

Maybe its just me but I didn't understand what you are
trying to do...

> The problem is to compute the number of trailing zero's in 
> factorials (n! =
> 1*2*3*4*.......*n). with n <= 1000000000
>
> My solution is as follows (a = times to read a number (b) to 
> process) :
>
> ---------------------------------------------------------------------------
>
> a = input()

what does a represent? Its usually worth putting a prompt string into
input() - and raw_input() - just as documentation if nothing else!
And maybe a descriptive variable name if appropriate.

> for i in range(a):
>    lst = (5, 25, 125, 625, 3125, 15625, 78125, 390625, 1953125, 
> 9765625,
> 48828125, 244140625)

None of these have any trailing zeros so far as I can tell?
What answer are you expecting from this function?

>    ans = 0
>    b = input()

similarly, what is b supposed to be?

>    for i in lst:

And here you are throwing away the i from the outer loop

>        if i <= b:
>            ans += b//i

And now you divide some arbitrary input value by each factorial
in turn and sum the results?

>    print ans

> Please, if you have suggestions to improve the speed of this 
> algorithm give
> an argumentation as to why a certain something is faster.

I nbeed to understand what you are tryying to do first, its
not making much sense at the moment. (But it is after midnight! :-)

> P.s. I know python is probably not the best language for these kinds 
> of
> problems (I can code it in C or C++), it just bugs me that it's 
> possible
> and my solution is failing...  ;-)

Actually it looks like exactly what I would use Python for rarther
than C/C++. The speed issue can be solved in numerous ways but
as always lets be sure we get the functionality clear before starting
to optimise things.

Alan G.