problemsFiltered.addElement(new Integer(i));
}
System.out.println("" + problemsFiltered.size() + " problems filtered");
if (f.sortByDifficulty != 0 || f.sortByGenre != 0 || f.sortByPopularity != 0)
new QuickSort(new ProblemComparator(problems, f)).sort(problemsFiltered);
else if (f.randomize) {
Random rand = new Random();
Vector shuffled = new Vector(problemsFiltered.size());
while (problemsFiltered.size() > 0) {
int i = rand.nextInt(problemsFiltered.size());