Re: random integer

bob@xxxxxxxxxxxxxx said:

I was just wondering what the best way to generate a uniformly
distributed random integer between 0 and x is.

Usually, you can't just do rand()%(x+1). For instance, if you want a
number between 0 and 31999, you can't just do rand()%32000 since
0-767 will be twice as likely.

Without getting seriously clever about it, you can do this:

int rir(int low, int high)
{
return (high - low + 1) * (rand() / (RAND_MAX + 1.0)) + low;
}

This won't give a perfectly uniform distribution, but it'll be a lot
better than a straight mod!

--
Richard Heathfield
"Usenet is a strange place" - dmr 29/7/1999
http://www.cpax.org.uk
email: rjh at the above domain, - www.
.