On Wed, Feb 18, 1998 at 07:42:19PM +1100, David Duffy wrote:

> But I can't
> see a way to generate the list of all 20 numbers in random order. The only

If you can generate one truly random seed, you can then use a pseudo-rando
number generator to generate a sequence that will be, for your purposes,
random. But if your seed is not truly random, you'll get the same sequences
repeating.

Here's a pseudo-random number generator (from the HI-TECH PIC C library)
.

You call srand with a random seed, then successive calls to rand() will return
a pseudo-random sequence based on that seed. The function is chaotic, i.e. a
 small
variation in the seed causes large variations in the sequence, but it
is deterministic, so it will only be as random as your seed.



#include        <stdlib.h>

static  long    randx;
static  char    randf;

void
srand(unsigned x)
{
        randx = x;
        randf = 1;
}

int
rand(void)
{
        if(!randf)
                srand(1);
        return((int)((randx = randx*1103515245L + 12345)>>16) & 077777);
}
--
Clyde Smith-Stubbs               |            HI-TECH Software
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