/* Generating a pseudo-random permutation of N integers.
   See p. 139 of "Seminumerical Algorithms, 2nd edition,"
   by Donald Knuth, for more details.  Thanks to Jason
   Bergner for sending me code implementing Knuth's algorithm.
*/

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

main()
{
	int		i, k, N = 10, a[100], temp;

  /* Initialize the random number generator, using
    the current time as a seed */
    
	srandom( (int)time(NULL) );


  /* Initialize the array to contain 0,1,2,...,N-1 */	

	for( i=0; i < N; i++ )
		a[i] = i;


  /* Do a bunch of random swaps--try it by hand to see
    what's happening. */
 
	for( i=N-1; i > 0; i-- )
	{
		k = (int)(random() % (i+1));
		temp = a[k];
		a[k] = a[i];
		a[i] = temp;
	}


  /* Here's the resulting permutation. */
 
	for( i=0; i < N; i++ )
		printf( "%d ", a[i] );
	putchar( '\n' );
}