/*
	qsortex.c
	By Jeff Ondich, 1/22/97

	Example of how to use the qsort() library function.
	
	Also, how to call a function that's passed to you
	as a parameter (see the calling() function below).
*/

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

#define		MAX		10

int		compare( const void *a, const void *b );
void	calling( int (*cmp)( const void *, const void * ) );

void main(void)
{
	int		i, key[MAX];

  /* Set up a random array of integers, and print them */

	srandom( time(NULL) );
	for( i=0; i < MAX; i++ )
	{
		key[i] = random() % MAX;
		printf( "%d ", key[i] );
	}
	printf( "\n" );


  /* Sort them and print the resulting list */
 
	qsort( key, MAX, sizeof(int), compare );

	for( i=0; i < MAX; i++ )
	{
		printf( "%d ", key[i] );
	}
	printf( "\n" );
	
	
  /* Demonstrate how a function calls another function
     that's passed to it as an argument. */

	printf( "And now to try calling a passed function:\n" );
	calling( compare );
}


int	compare( const void *a, const void *b )
{
	return( *((int *)a) - *((int *)b) );
}


void calling( int (*thefunction)( const void *, const void * ) )
{
	int		p=1, q=2;

	if( (*thefunction)(&p,&q) > 0 )
		printf( "1 > 2\n" );
	else
		printf( "1 <= 2\n" );
}