/**

 * fak.c

 * Copyright (C) 2008 Markus Broeker

 */

#include <stdio.h>

#include <stdlib.h>

unsigned long fak (short i)

{

    if (i == 0)

        return 1;

    else if (i > 0)

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

    else

        return (i * fak (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) {

        printf ("NUMBER FORMAT ERROR\n");

        return EXIT_FAILURE;

    }

    printf ("The faktorial of %d is %lu\n", number, fak (number));

    return EXIT_SUCCESS;

}