u6
Class HeapPriorityQueue

java.lang.Object
  |
  +--u6.HeapPriorityQueue

public class HeapPriorityQueue

extends java.lang.Object

implements PriorityQueue

Heap implementation of the PriorityQueue. Stores elements of the key-element pair type in a Heap structure.

Constructor Summary

HeapPriorityQueue(java.util.Comparator cmp)

HeapPriorityQueue(Heap emptyHeap)

Method Summary

java.lang.Object	extract() Extracts the element with greater priority, i.e. with minimal key.
void	insert(java.lang.Object key, java.lang.Object element) Inserts an element with priority key in this priority queue.
boolean	isEmpty() Checks whether this priority queue is empty.
java.lang.Object	minKey() Reads the minimal key in this priority queue, without removing the element.
java.lang.Object	minKeyElement() Reads the element with minimal key.
int	size() Gets the number of entries in this priority queue.

Methods inherited from class java.lang.Object

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

Constructor Detail

HeapPriorityQueue

public HeapPriorityQueue(Heap emptyHeap)

HeapPriorityQueue

public HeapPriorityQueue(java.util.Comparator cmp)

Method Detail

insert

public void insert(java.lang.Object key,
                   java.lang.Object element)

Inserts an element with priority key in this priority queue.

Specified by:

insert in interface PriorityQueue

Parameters:

key - the priority value; smaller keys represent greater priority.

element - the element value;

extract

public java.lang.Object extract()

Extracts the element with greater priority, i.e. with minimal key.

Specified by:

extract in interface PriorityQueue

Returns:

the element with minimal key

size

public int size()

Gets the number of entries in this priority queue.

Specified by:

size in interface PriorityQueue

Returns:

the number of elements

isEmpty

public boolean isEmpty()

Checks whether this priority queue is empty.

Specified by:

isEmpty in interface PriorityQueue

Returns:

true iff this priority queue is empty

minKey

public java.lang.Object minKey()

Reads the minimal key in this priority queue, without removing the element.

Specified by:

minKey in interface PriorityQueue

minKeyElement

public java.lang.Object minKeyElement()

Reads the element with minimal key.

Specified by:

minKeyElement in interface PriorityQueue