Data Structures and Algorithms
with Object-Oriented Design Patterns in Java 
The definitions of the StackAsArray constructor
and purge methods are given in Program 
.
The constructor takes a single parameter, size,
which specifies the maximum number of items that can be stored in the stack.
The variable array is initialized to be an array of length size.
The constructor requires O(n) time to construct the array,
where 
.
Program: StackAsArray class constructor and purge methods.
The purpose of the purge method is to remove all
the contents of a container.
In this case, the objects in the stack occupy the first count
positions of the array.
To empty the stack,
the purge method simply assigns the value null
to the first count positions of the array.
Clearly, the running time for the purge method is O(n),
where 
.
Copyright © 1998 by Bruno R. Preiss, P.Eng. All rights reserved.