IEnumerable <Tuple <int, string> > Tuples(IndexPQBase <string> pq)
{
foreach (int i in pq)
{
yield return(new Tuple <int, string>(i, pq.KeyOf(i)));
}
}
IEnumerable <string> Strings(IndexPQBase <string> pq)
{
foreach (int i in pq)
{
yield return(i.ToString());
yield return(pq.KeyOf(i));
}
}