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From: gary@hpavla.HP.COM (Gary Jackoway)
Newsgroups: comp.lang.c
Subject: Re: Random number generator
Message-ID: <940001@hpavla.HP.COM>
Date: 22 Dec 89 14:58:29 GMT
References: <83943@linus.UUCP>
Organization: Hewlett-Packard Avondale Division
Lines: 18


> I was trying to generate a random number bewteen 0 and maxlongint (i.e. 2^32)
> on my machine (80386 with Interactive). The rand() function that I have
> returns a psuedo-random number between 0 and MAXINT (which in this case
> is 32768). 
----------
Simply put two rand's together:

       longrand = (unsigned long) rand() | ((unsigned long) rand() << 32);

This should give you a uniform distribution.
I should warn you that rand() is often NOT a good random number generator,
so if the application is sensitive, be sure to run randomness tests on
your long random numbers.

No charge,

Gary Jackoway