it.unimi.dsi.fastutil

Class PriorityQueues.EmptyPriorityQueue

java.lang.Object

it.unimi.dsi.fastutil.AbstractPriorityQueue

it.unimi.dsi.fastutil.PriorityQueues.EmptyPriorityQueue

All Implemented Interfaces:

PriorityQueue

Enclosing class:

PriorityQueues

public static class PriorityQueues.EmptyPriorityQueue
extends AbstractPriorityQueue

An immutable class representing the empty priority queue.

This class may be useful to implement your own in case you subclass PriorityQueue.

Method Summary

Modifier and Type	Method and Description
void	changed() Notifies the queue that the first element has changed (optional operation).
void	clear() Removes all elements from this queue.
Comparator<?>	comparator() Returns the comparator associated with this queue, or null if it uses its elements' natural ordering.
Object	dequeue() Dequeues the first element from the queue.
void	enqueue(Object o) Enqueues a new element.
Object	first() Returns the first element of the queue.
boolean	isEmpty() Checks whether the queue is empty.
Object	last() Returns the last element of the queue, that is, the element the would be dequeued last (optional operation).
int	size() Returns the number of elements in this queue.

Methods inherited from class java.lang.Object

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

Method Detail

enqueue

public void enqueue(Object o)

Description copied from interface: PriorityQueue

Enqueues a new element.

Parameters:

o - the element to enqueue..

dequeue

public Object dequeue()

Description copied from interface: PriorityQueue

Dequeues the first element from the queue.

Returns:

the dequeued element.

isEmpty

public boolean isEmpty()

Description copied from interface: PriorityQueue

Checks whether the queue is empty.

Specified by:

isEmpty in interface PriorityQueue

Overrides:

isEmpty in class AbstractPriorityQueue

Returns:

true if the queue is empty.

size

public int size()

Description copied from interface: PriorityQueue

Returns the number of elements in this queue.

Returns:

the number of elements in this queue.

clear

public void clear()

Description copied from interface: PriorityQueue

Removes all elements from this queue.

first

public Object first()

Description copied from interface: PriorityQueue

Returns the first element of the queue.

Returns:

the first element.

last

public Object last()

Description copied from interface: PriorityQueue

Returns the last element of the queue, that is, the element the would be dequeued last (optional operation).

Specified by:

last in interface PriorityQueue

Overrides:

last in class AbstractPriorityQueue

Returns:

the last element.

changed

public void changed()

Description copied from interface: PriorityQueue

Notifies the queue that the first element has changed (optional operation).

Specified by:

changed in interface PriorityQueue

Overrides:

changed in class AbstractPriorityQueue

comparator

public Comparator<?> comparator()

Description copied from interface: PriorityQueue

Returns the comparator associated with this queue, or null if it uses its elements' natural ordering.

Returns:

the comparator associated with this sorted set, or null if it uses its elements' natural ordering.