Data Structures and Algorithms
with Object-Oriented Design Patterns in C++ 
In this chapter we consider sets the elements of which are integers.
By using integers as the universe rather than arbitrary objects,
certain optimizations are possible.
For example, we can use a bit-vector of length N
to represent a set whose universe is 
.
Of course, using integers as the universe does not preclude the use of
more complex objects,
provided there is a one-to-one mapping between those objects
and the elements of the universal set.
A crucial requirement of any set representation scheme is that it supports the common set operations including union , intersection and set difference . We also need to compare sets and, specifically, to determine whether a given set is a subset of another.
Copyright © 1997 by Bruno R. Preiss, P.Eng. All rights reserved.