From:	"A. Sinan Unur" <sinan DOT unur AT cornell DOT edu>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Easy question...
Date:	Mon, 16 Mar 1998 06:55:54 -0500
Organization:	Cornell University (http://www.cornell.edu/)
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DeHackEd wrote:
> 
> rand() and random() take no arguements. They return numbers from 0 to 
> RAND_MAX or INT_MAX (not sure which). If you want to limit what they 
> return, use a mod (rand()%10)command. If you want either 0 or 1, use 
> random()&0x400 for safety, as random generators are not as random as 
> one would hope.

you don't necessarily have to worry about this if you are just writing a
game, but a more proper way of generating a bernoulli (success/fail,
coin toss) random variable with probability of success p would be to use

#include <stdlib.h>

int bernoulli(double p)
{
  return rand() > p*RAND_MAX;
}

-- Sinan
----------------------------------------------------------------------
A. Sinan Unur
Department of Policy Analysis and Management, College of Human Ecology,
Cornell University, Ithaca, NY 14853, USA

mailto:sinan DOT unur AT cornell DOT edu
http://www.people.cornell.edu/pages/asu1/

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