Class ArrayBasedQueue<E>

java.lang.Object

ArrayBasedQueue<E>

All Implemented Interfaces:

java.lang.Iterable<E>, QueueInterface<E>

public class ArrayBasedQueue<E>
extends java.lang.Object
implements QueueInterface<E>

Field Summary

Fields

Modifier and Type	Field and Description
private E[]	arr
private int	back
private int	front
private int	size

Constructor Summary

Constructors

Constructor and Description
ArrayBasedQueue()

Method Summary

Modifier and Type	Method and Description
private int	decrementIndex(int index)
E	dequeue() Retrieves and removes the element at the head of this queue.
E	dequeue(int index) Retrieves and removes the element at the specified index.
void	enqueue(E e) Adds the specified element into the stack if it is possible to do so immediately without violating capacity restrictions, otherwise, throwing an IllegalStateException if no space is currently available or NullPointerException if the specified element is null.
private int	findIndex(int index)
private int	incrementIndex(int index)
boolean	isEmpty() This method is called to determine if the queue is empty.
java.util.Iterator<E>	iterator()
E	peek() Retrieves, but does not remove, the head of this queue.
void	removeAll() Removes all elements from the queue.
int	size() This method is called to obtain the count of elements in the list.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

arr

private E[] arr

size

private int size

front

private int front

back

private int back

Constructor Detail

ArrayBasedQueue

public ArrayBasedQueue()

Method Detail

incrementIndex

private int incrementIndex(int index)

decrementIndex

private int decrementIndex(int index)

findIndex

private int findIndex(int index)

isEmpty

public boolean isEmpty()

Description copied from interface: QueueInterface

This method is called to determine if the queue is empty.

Specified by:

isEmpty in interface QueueInterface<E>

Returns:

Returns true if the queue is empty, otherwise it returns false.

size

public int size()

Description copied from interface: QueueInterface

This method is called to obtain the count of elements in the list.

Specified by:

size in interface QueueInterface<E>

Returns:

Returns the numbers of elements that are currently in the queue.

enqueue

public void enqueue(E e)
             throws java.lang.IllegalStateException,
                    java.lang.NullPointerException

Description copied from interface: QueueInterface

Adds the specified element into the stack if it is possible to do so immediately without violating capacity restrictions, otherwise, throwing an IllegalStateException if no space is currently available or NullPointerException if the specified element is null.

Specified by:

enqueue in interface QueueInterface<E>

Parameters:

e - The element to add.

Throws:

java.lang.IllegalStateException - If the element cannot be added at this time due to capacity restrictions.

java.lang.NullPointerException - If the specified element being added is null.

peek

public E peek()

Description copied from interface: QueueInterface

Retrieves, but does not remove, the head of this queue.

Specified by:

peek in interface QueueInterface<E>

Returns:

The element at the head of the queue or null if the queue is empty.

dequeue

public E dequeue()

Description copied from interface: QueueInterface

Retrieves and removes the element at the head of this queue.

Specified by:

dequeue in interface QueueInterface<E>

Returns:

The element at the head of the queue or null if the queue is empty.

dequeue

public E dequeue(int index)
          throws java.util.NoSuchElementException

Description copied from interface: QueueInterface

Retrieves and removes the element at the specified index.

Specified by:

dequeue in interface QueueInterface<E>

Parameters:

index - The index of the element to be removed.

Returns:

The element at the specified index.

Throws:

java.util.NoSuchElementException - If the specified index is invalid.

removeAll

public void removeAll()

Description copied from interface: QueueInterface

Removes all elements from the queue.

Specified by:

removeAll in interface QueueInterface<E>

iterator

public java.util.Iterator<E> iterator()

Specified by:

iterator in interface java.lang.Iterable<E>