13.1

#include <stdio.h>
#include <conio.h>

long int faktorial(unsigned int n)
{
	if (n == 0 || n == 1) {
		return 1;
	} else {
		return n * faktorial(n - 1);
	}
}

int main()
{
	int n;
	long int hasil;
	
	printf("masukan nilai n = ");
	scanf("%d", &n);
	
	hasil = faktorial(n);
	
	printf("Hasil %d ! = %ld ", n, hasil);
	
	return 0;
}