C program to find factorial of a given number.

/* C program to find factorial of a given number. Factorial of number n is defined as follow:

      n! = 1 * 2 * 3 * 4 * ....* n 

*/
#include<stdio.h>
int main()
{
   int i, n;
   double fact=1;
    
printf("Enter number (n): ");
   scanf("%d",&n);

   if (n < 0)
      printf("Factorial is not possible for negative number.");
   else
   {
      for(i=1; i<=n; i++)
      {
          fact = fact * i;     
      }
      printf("Factorial of number %d = %f", n, fact);
   }
}

* * * * *

Output of program:

Enter number (n): 5
Factorial of number 5 = 120.000000