/*param size: number of unique numbers to generate*
 *param seed: the seed to determine the randomness*
 *initialize the generator*/
initialize_uniques(size_t size, int seed);

/*return: random integer between 0 and integers_left()*
 *if generator isn't initialized, initialize default value and seeds to time(NULL)*/
int generate_uniques();

/*returns number of uniques numbers left after initialization*/
void uniques_left()