Graphs, directed graphs, trees and binary trees appear in many areas of mathematics and computer science.
This and the next two chapters will cover these topics. However, in order to understand how these objects may be
stored in memory and to understand algorithms on them, we need to know a little about certain data structures.
We assume the reader does understand linear and two-dimensional arrays; hence we will only discuss linked lists
and pointers, and stacks and queues below.
Linked Lists and Pointers
Linked lists and pointers will be introduced by means of an example. Suppose a brokerage ?rm maintains a
?le in which each record contains a customer’s name and salesman; say the ?le contains the following data:
Customer Adams Brown Clark Drew Evans Farmer Geller Hiller Infeld