/* https://stackoverflow.com/questions/2999075/generate-a-random-number-within-range/2999130#2999130 */
int rand_lim(int limit) {
/* return a random number between 0 and limit inclusive.
 */

    int divisor = RAND_MAX/(limit+1);
    int retval;

    do { 
        retval = rand() / divisor;
    } while (retval > limit);

    return retval;
}