code: private static int med3(Quicksortable q, int a, int b, int c) {
          return (q.compare(a, b) < 0 ?
                  (q.compare(b, c) < 0 ? b : q.compare(a, c) < 0 ? c : a) :
                  (q.compare(b, c) > 0 ? b : q.compare(a, c) > 0 ? c : a));
      }
docs: /*
  Returns the index of the median of the three indexed integers.