#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int factorial (int);

int main()  {

	int i=1, n, n0=6;

	// Calculate factorial with while loop
	n = n0;
	while (n > 0)
	  i *= n--;

	printf("\nThe factorial of %d is %d. \n\n", n0, i);
	
	// Calculate factorial with recursive function
	printf("\nThe factorial of %d is still %d. \n\n", n0, factorial(n0));

	return;
}

int factorial (int number)  {

	if (number <= 1)  
	  return 1;

	return number * factorial(number - 1);
}