// Factorial Calculator By Mehrdad Jamali 86442125.
// http://mehrdad.znuclub.com
// jamali.mehrdad@gmail.com
# include <stdio.h>
# include <conio.h>
# include <math.h>
float getex(double);
main()
{
int i,n;
double s=0.0,a,b;
clrscr();
printf("*** Factorial Calculator *** \n.:: Mehrdad Jamali ::. Stu#:86442125 \n--------------------------------\n");
printf("Please enter N to Calculate N! :");
scanf("%d",&n);
if (n>=0)
{
printf("\nPlease wait , calculating ...\n");
// calculating s = Siq (i=1 to n) [ Log i ]
for (i=1;i<=n;i++)
s+=log10(i);
b = floor(s);
// End of Calculating S
a = getex(s-b);
printf("\n\n\n Result: %d! ~= %5.4f e+%d\n\n-----------\n",n,a,(int)(b));
printf("[[[ Please enter any key to exit ... ]]]");
}
else
{
clrscr();
printf("Invalid arrgument found ,\n [[[ please enter any key to exit ... ]]]");
}
getch();
}
float getex(double p)
{
float r;
r = pow(10,p);
return r;
}