From:	Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: rand and random
Date:	Tue, 2 Nov 1999 11:25:49 +0200
Organization:	NetVision Israel
Lines:	21
Message-ID:	<Pine.SUN.3.91.991102112306.20126N-100000@is>
References:	<s1n73iu5iqi71 AT corp DOT supernews DOT com> <p6obOB+BRMP7QeUGn1Z+l2JBPBVt AT 4ax DOT com> <Pine DOT SUN DOT 3 DOT 91 DOT 991031100828 DOT 2988f-100000 AT is> <xIgeOAnzj2KaFWlGUNnv=obD+Vkp AT 4ax DOT com>
NNTP-Posting-Host:	is.elta.co.il
Mime-Version:	1.0
X-Trace:	news.netvision.net.il 941534673 617 199.203.121.2 (2 Nov 1999 09:24:33 GMT)
X-Complaints-To:	abuse AT netvision DOT net DOT il
NNTP-Posting-Date:	2 Nov 1999 09:24:33 GMT
X-Sender:	eliz AT is
In-Reply-To:	<xIgeOAnzj2KaFWlGUNnv=obD+Vkp@4ax.com>
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp
Reply-To:	djgpp AT delorie DOT com
X-Mailing-List:	djgpp AT delorie DOT com
X-Unsubscribes-To:	listserv AT delorie DOT com

On Tue, 2 Nov 1999, Damian Yerrick wrote:

> > `rand' returns a random integer between 0 and RAND_MAX.  The latter is
> > defined on stdlib.h, and is much larger than 32K.
> 
> I thought some C standard defined rand() as
> 
> #define RAND_MAX 0x7fff
> int rand(void)
> {
>   mySeed = (mySeed * 1103515245) + 12345;
>   return (mySeed & 0x7fff0000) >> 16;
> }

This is the *minimal* version of the generator recommended by the 
Standard.  It is compatible with the Standard's requirement that an int 
be at least 16-bit wide.

Most (if not all) 32-bit implementations provide a generator with
the full 32-bit range.

- Raw text -