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[QUOTE="Frank Silvermann, post: 2468586"]
/* rand_in_range.c : contributors: usual suspects in clc */

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <math.h>
#define SWAP(m, n) (tmp = (m), (m) = (n), (n) = tmp)
#define ITERATIONS 100

int rand_in_range(int, int);

int main(void)
{
int tja, i , j, m, n;
/* all declarations in main need to be north of here */
/* seed timer */
srand(time(NULL));
/* call rand and count returns */
j = 0;
m = 8;
n = 3;
printf("range is [%d, %d]\n", m, n);
for (i=0; i < ITERATIONS; i++)
{
tja = rand_in_range(m, n);
if (i < 10) printf("return is %d\n", tja);
j += tja;
}
printf("total is %d\n", j);
return 0;
}

int rand_in_range(int m, int n)
{
/*seed srand in main */
/* [m, n] is range */
int t, top, diff, p, tmp;
if (m == n) return m;
if (m > n) SWAP(m, n);
diff = n - m;
top = RAND_MAX - (RAND_MAX % (diff + 1) + 1);

/* control */
do t = rand();  while (t > top);
p = t % (diff + 1) ;
p = p + m;
return p;
}
/* end source */
I think this is right.  frank
[/QUOTE]

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