/* irand.c -- pick a random integer
 * 
 * unsigned	r, M;
 * r = irand(M);
 *
 * irand returns a random non-negative integer less than M.
 */
#include "common.h"
#include "stdlib.h"

#define	MAXRAND	(RAND_MAX)		/* max random integer		*/

long	random();

int
irand(M)
unsigned	M;
{
    double		r;
    unsigned		ir;

    r = random();
    r /= MAXRAND + 1.0;
    ir = r * M;
    if (ir >= M) ir = M-1;
    return(ir);
}