harpoon.Util
Interface MaxPriorityQueue

All Superinterfaces:

Collection, Iterable

All Known Implementing Classes:

BinHeapPriorityQueue

public interface MaxPriorityQueue
extends Collection

MaxPriorityQueue maintains a Collection of Objects, each with an associated priority. Implementations should make the peekMax and removeMax operations efficient. Implementations need not implement the Object-addition operations of the Collection interface, since they do not associate each added Object with a priority.

Version:

$Id: MaxPriorityQueue.java,v 1.3 2002/04/23 22:29:05 ovy Exp $

Author:

Felix S. Klock II <pnkfelix@mit.edu>

Method Summary

void	changePriority(Object item, int delta) Change the priority of this element by the specified delta.
Object	deleteMax() Returns and removes the Object in this with the highest priority.
int	getPriority(Object item) Returns the priority currently associated with this item.
boolean	insert(Object item, int priority) Inserts item into this, assigning it priority priority.
Object	peekMax() Returns the Object in this with the highest priority.
int	setPriority(Object item, int newPriority) Changes the priority of this Object to the new, specified value, and returns the old value

Methods inherited from interface java.util.Collection

add, addAll, clear, contains, containsAll, equals, hashCode, isEmpty, iterator, remove, removeAll, retainAll, size, toArray, toArray

Method Detail

insert

boolean insert(Object item,
               int priority)

Inserts item into this, assigning it priority priority.

Parameters:

item - Object being inserted

priority - Priority of item

peekMax

Object peekMax()

Returns the Object in this with the highest priority.

deleteMax

Object deleteMax()

Returns and removes the Object in this with the highest priority.

getPriority

int getPriority(Object item)

Returns the priority currently associated with this item.

setPriority

int setPriority(Object item,
                int newPriority)

Changes the priority of this Object to the new, specified value, and returns the old value

changePriority

void changePriority(Object item,
                    int delta)

Change the priority of this element by the specified delta. This is equivalent to setPriority(item, getPriority(item)+delta). It might save time in some implementations.