Class DLDeque

java.lang.Object
  |
  +--DLDeque

All Implemented Interfaces:

Deque

class DLDeque

extends java.lang.Object

implements Deque

DLDeque is an implementation of Deque, a repository for Objects. that maintains insertion order. Objects can be inserted and removed from either in. Objects are inserted using enqueue and removed using dequeue. A doubly-linked list is used to maintain the Deque.

Nested Class Summary

(package private) class

DLDeque.Dcell A Dcell stores one Object in the Queue and points to the immediately following and preceding Dcells, if any.

Field Summary

(package private) DLDeque.Dcell	back the Dcell at the back
(package private) DLDeque.Dcell	front the Dcell at the front

Constructor Summary

DLDeque()
Construct an empty DLDeque.

Method Summary

java.lang.Object	dequeueBack() Remove an Object from the back of the Deque.
java.lang.Object	dequeueFront() Remove an Object from the front of the Deque.
void	enqueueBack(java.lang.Object item) Insert an Object at the back of the Deque.
void	enqueueFront(java.lang.Object item) Insert an Object at the front of the Deque.
boolean	isEmpty() Indicate whether or not the Deque is empty

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

front

DLDeque.Dcell front

the Dcell at the front

back

DLDeque.Dcell back

the Dcell at the back

Constructor Detail

DLDeque

public DLDeque()

Construct an empty DLDeque.

Method Detail

enqueueBack

public void enqueueBack(java.lang.Object item)

Insert an Object at the back of the Deque.

Specified by:

enqueueBack in interface Deque

Parameters:

item - the Object to be inserted

dequeueFront

public java.lang.Object dequeueFront()
                              throws EmptyQueueException

Remove an Object from the front of the Deque.

Specified by:

dequeueFront in interface Deque

Returns:

the Object removed

Throws:

EmptyQueueException - if the Queue is empty

enqueueFront

public void enqueueFront(java.lang.Object item)

Insert an Object at the front of the Deque.

Specified by:

enqueueFront in interface Deque

Parameters:

item - the Object to be inserted

dequeueBack

public java.lang.Object dequeueBack()
                             throws EmptyQueueException

Remove an Object from the back of the Deque.

Specified by:

dequeueBack in interface Deque

Returns:

the Object removed

Throws:

EmptyQueueException - if the Queue is empty

isEmpty

public boolean isEmpty()

Indicate whether or not the Deque is empty

Specified by:

isEmpty in interface Deque

Returns:

boolean indicating whether or not the Deque is empty