hw5.problem1

Class IntQueue1

java.lang.Object

hw5.problem1.IntQueue1

public class IntQueue1
extends Object

IntQueue1 is our first implementation of a basic first-in, first-out queue for Integers.

An IntQueue can be described as [n1, n2, ..., n_k], where n1 is the least-recently-added item in the queue and is the next item to be removed. n_k is the most-recently-added and will be the last of the current elements to be removed.

An IntQueue can also be described constructively, with the append operation, ':', such that [n1, n2, ..., n_k] : n_k+1 is the result of enqueing n_k+1 at the end of the queue.

Constructor Summary

Constructors

Constructor and Description
IntQueue1()

Method Summary

Methods

Modifier and Type	Method and Description
void	checkRep()
Integer	dequeue() Dequeue an item
void	enqueue(Integer entry) Enqueue an item
Integer	front() See the next item without removing it
boolean	isEmpty()
int	size()

Methods inherited from class java.lang.Object

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

Constructor Detail

IntQueue1

public IntQueue1()

Effects:

constructs an empty queue

Method Detail

enqueue

public void enqueue(Integer entry)

Enqueue an item

Parameters:

entry - item to be added to the queue

Throws:

IllegalArgumentException - if entry is null

Effects:

places entry at the end of the queue

Modifies:

this

dequeue

public Integer dequeue()

Dequeue an item

Returns:

the item that was first in the queue

Requires:

size() > 0

Effects:

removes the item at the front of the queue

Modifies:

this

front

public Integer front()

See the next item without removing it

Returns:

the item currently first in the queue

Requires:

size() > 0

size

public int size()

Returns:

number of elements in the queue

isEmpty

public boolean isEmpty()

Returns:

size() == 0

checkRep

public void checkRep()