There are no essential prerequisites for solving this problem. An understanding of
what a set is (“a collection of objects” is a sufficient definition) and what a subset is
(any set all of whose elements come from the original set, including Ø--the empty
set--and the whole set) is enough to get started.
Familiarity with graph theory and recursive definitions for functions or algorithms
will help in the final solution, but those ideas can be picked up through working on
the problem.
