/**

 * fak.c

 * Copyright (C) 2008 Markus Broeker

 */

#include <stdio.h>

#include <stdlib.h>

unsigned long long fak (short i)

{

    if (i == 0)

        return 1;

    return (i * fak (i - 1));

}

long double bigfak (short i)

{

    if (i == 0)

        return 1;

    return (i * bigfak (i - 1));

}

int main (int argc, char **argv)

{

    short number;

    printf ("Enter a number: ");

    if (scanf ("%hd", &number) != 1) {

        printf ("READ ERROR\n");

        return EXIT_FAILURE;

    }

    if (number < 0 || number > 170) {

        printf ("Range Error: %hd ! {0..170}\n", number);

        return EXIT_FAILURE;

    }

    if (number > 20)

        printf ("The factorial of %2d is %1.5Lg\n", number, bigfak (number));

    else

        printf ("The factorial of %2d is %llu\n", number, fak (number));

    return EXIT_SUCCESS;

}