It is trivial that with the above scenario, INSERTION
SORT is the only optimal sorting algorithm as there are no
other possible alternative approaches that can satisfy all
the above constraints, thus we have to relax some of the
requirements—this paper assumes select does not need
to run in O(1) time, meaning partial order is tolerable until
all elements in X are inserted. It is essential that select
should still run reasonably fast, or it will lose the purpose
of being incremental