Program declares the `GraphAsLists` concrete class.
The `GraphAsLists` class is derived from
the abstract base class `Graph`.
The `GraphAsLists` class represents the edges
of a graph using adjacency lists.

**Program:** `GraphAsLists` Class Definition

Two member variables are declared--`vertices` and `adjacencyLists`.
The former is an array of pointers to `Vertex` instances.
This array is used to represent the elements of the vertex set .

The second member variable is an array of linked lists of pointers to edges.
The linked list, `adjacencyLists[i]`,
represents the set which is
the set of edges emanating from vertex .
The implementation uses the `LinkedList<T>` class
given in Section .

The `GraphAsLists` constructor takes a single argument
of type `unsigned int` that specifies
the maximum number of vertices that the graph may contain.
This quantity specifies the lengths of the
array of vertices and the array of adjacency lists.
The implementation of the `GraphAsLists` class is left
as programming project for the reader (Project ).

Copyright © 1997 by Bruno R. Preiss, P.Eng. All rights reserved.