[sgt/puzzles] / misc.c

/*
 * misc.c: Miscellaneous helpful functions.
 */

#include <assert.h>
#include <stdlib.h>

#include "puzzles.h"

int rand_upto(int limit)
{
    unsigned long divisor = RAND_MAX / (unsigned)limit;
    unsigned long max = divisor * (unsigned)limit;
    unsigned long n;

    assert(limit > 0);

    do {
        n = rand();
    } while (n >= max);

    n /= divisor;

    return (int)n;
}
Commit	Line	Data
4efb3868	1	/*
	2	* misc.c: Miscellaneous helpful functions.
	3	*/
	4
	5	#include <assert.h>
	6	#include <stdlib.h>
	7
	8	#include "puzzles.h"
	9
	10	int rand_upto(int limit)
	11	{
	12	unsigned long divisor = RAND_MAX / (unsigned)limit;
	13	unsigned long max = divisor * (unsigned)limit;
	14	unsigned long n;
	15
	16	assert(limit > 0);
	17
	18	do {
	19	n = rand();
	20	} while (n >= max);
	21
	22	n /= divisor;
	23
	24	return (int)n;
	25	}