🚀 go-pugleaf

In article <31224679.6193@born.com>, John Cleland  <clelaj@born.com> wrote:
)The Crow wrote:
)> 
)> Here is what I am trying to do, I want to find the last NON-ZERO digit of a
)> given factorial.  For instance,
)> 
)> 5! = 120
)> 
)> so the last non-zero digit is 2.  I want to be able to do this up to 1000.
)> Problem is, no matter how huge of a data-type you use, there isn't any way for
)> the computer to handle 1000!, it is however possible to find the last non-zero
)> digit somehow.  One thing I have tried is as I went through mulitplying the
)> series of numbers in the factorial (5 * 4 * 3 * 2) I would remove all the
)> trailing ZEROS, I got this to work up to 789, but it wont work with 1000 and i
)> am not really sure why.  If anyone has a clue how I can do this let me know.
)
)Don't just strip the trailing zeros, remove all digits except the last non-zero
)digit (which is your output) and then multiply by the next number in your sequence.
)This keeps the numbers down to a managable level and gives the correct answer as
)no more significant digit can affect the value of the LSD.

Let's try your technique:

	1! = 1 ~ 1
	2! = 2x1! ~ 2
	3! = 3x2! ~ 3x2 = 6
	4! = 4x3! ~ 4x6 = 24 ~ 4
	5! = 5x4! ~ 5x4 = 20 ~ 0

You should at least think before engaging the fingers.

Mike
----
char *p="char *p=%c%s%c;main(){printf(p,34,p,34);}";main(){printf(p,34,p,34);}

I don't speak for DSC.         <- They make me say that.