|
Data Structures and Algorithms
with Object-Oriented Design Patterns in Python |
The definitions of the StackAsArray __init__
and purge methods are given in Program 
.
In addition to self,
the __init__ method 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 __init__ method requires O(n) time to construct the array,
where 
.
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 None
to the first _count positions of the array.
Clearly, the running time for the purge method is O(n),
where 
.
Copyright © 2003, 2004 by Bruno R. Preiss, P.Eng. All rights reserved.