Interface PriorityQueue<T extends java.lang.Comparable<? super T>>

Type Parameters:

T - the type of data the queue stores.

All Known Subinterfaces:

UpdatablePriorityQueue<T,P>

All Known Implementing Classes:

MysteryPriorityQueueImplementation, MysteryUpdatablePriorityQueueImplementation

public interface PriorityQueue<T extends java.lang.Comparable<? super T>>

A Java interface for the Priority Queue ADT.

Note that the relative priority of elements is defined by the compareTo() method defined for the type of items stored in the queue. In other words, the priority of an item is equal to the value of the item.

Note that this interface defines a *max* priority queue; the item with the highest priority is what comes out of the queue. The easiest way to get a *min* priority queue is to separate priorities and values (in a PriorityPair), and negate the priorities that you use.

See Also:

PriorityPair, DefaultPriorityPairImplementation

Method Summary

Modifier and Type	Method and Description
void	add(T item) Adds an item to the queue.
void	clear() Removes all items from the queue.
boolean	isEmpty() Returns true if the queue is empty.
T	peek() Returns the maximum item in the queue, without removing it.
T	remove() Removes the maximum item from the queue, and returns it.

Method Detail

add

void add(T item)

Adds an item to the queue.

Throws:

java.lang.IllegalArgumentException - if item is null.

remove

T remove()

Removes the maximum item from the queue, and returns it.

Returns:

null if the queue is empty.

peek

T peek()

Returns the maximum item in the queue, without removing it.

Returns:

null if the queue is empty.

isEmpty

boolean isEmpty()

Returns true if the queue is empty.

clear

void clear()

Removes all items from the queue.