edu.northwestern.at.utils

Class QueueStack<E>

java.lang.Object

edu.northwestern.at.utils.QueueStack<E>

public class QueueStack<E>
extends java.lang.Object

A stack implemented using a single-ended queue.

We actually use an ArrayList to mimic a queue.

Field Summary

Fields

Modifier and Type	Field and Description
protected java.util.ArrayList<E>	queue The queue which is used to hold the stack entries.

Constructor Summary

Constructors

Constructor and Description
QueueStack() Create an empty stack.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	isEmpty() Check if stack is empty.
E	peek() Peek at top element of stack without removing it.
E	pop() Remove element from stack.
void	push(E e) Add element to stack.
int	size() Number of entries in stack.

Methods inherited from class java.lang.Object

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

Field Detail

queue

protected java.util.ArrayList<E> queue

The queue which is used to hold the stack entries.

Constructor Detail

QueueStack

public QueueStack()

Create an empty stack.

Method Detail

isEmpty

public boolean isEmpty()

Check if stack is empty.

Returns:

true if stack is empty.

peek

public E peek()

Peek at top element of stack without removing it.

Returns:

Element returned.

Throws:

EmptyQueueStackException - when stack is empty.

pop

public E pop()

Remove element from stack.

Returns:

Element returned.

Throws:

EmptyQueueStackException - when stack is empty.

push

public void push(E e)

Add element to stack.

Parameters:

e - Element to add to stack.

size

public int size()

Number of entries in stack.

Returns:

Number of entries in stack.