/*
	main.c
	
	Started by Jeff Ondich on 1/3/96
	Last modified 4/1/97
	
	This main program is intended to be compiled together with
	factorial.c (and the header file factorial.h).

	1. Read main.c.  Without looking at factorial.c, what do
	you expect the full program to do?
	
	2. Read factorial.h.  This is a "header" file, and contains
	the interface to my ultra-tiny "factorial library."  After
	reading factorial.h, a programmer should be able to use the
	factorial library without looking at the implementation in
	factorial.c.

	3. Read factorial.c.  This is the implementation of the
	factorial library.  Questions about the code?  Ask them.
	Notice how function return types and parameter lists are specified
	in C as opposed to Pascal.
	
	Compile the full program like so:
  
  		cc -Wall -o factorial main.c factorial.c

	Did it compile?  Did it run?  Did it do what you expected
	it to do?
	
	4. Leave out the #include "factorial.h" from main.c and
	recompile.  What do you expect?  Were you right?
*/




#include	<stdio.h>
#include	"factorial.h"

void main( void )
{
	int		theNumber, fact;
	
	printf( "Please enter a number: " );
	scanf( "%d", &theNumber );
	
	fact = factorial(theNumber);
	if( theNumber < 0 )
		printf( "Negative numbers don't have factorials.\n" );

	else if( fact <= 0 )
		printf( "%d is too big\n", theNumber );

	else
		printf( "%d! = %d\n", theNumber, fact );
}