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com.cosylab.util
Class Heap

java.lang.Object
  com.cosylab.util.Heap

public class Heap
extends java.lang.Object

Simple heap implementation. This implementation uses Comparable interface to maintain ascending order. Heap will grow and shrink based on number of elements. If total number of elements equals internal array size, this array is expanded by factor of 2. If number of elements is less than one quarter the array size, array will be shrunk to by half.
Implementation is synchronized and can be considered thread-safe.

Version:

$id$

Author:

Ales Pucelj

Constructor Summary

Heap()
Default constructor for Heap().

Heap(int initialSize)
Alternate constructor for heap that allows specification of initial size.

Method Summary

void	add(java.lang.Comparable c) Adds new element to the heap.
java.lang.Comparable	get(int index) Returns element at index.
java.lang.Comparable	getFirst() Returns smallest element or null if empty.
boolean	isEmpty() True if heap is empty.
static void	main(java.lang.String[] args) Run test applet.
java.lang.Comparable	remove() Removes smallest element.
int	size() Size of the heap.
java.lang.String	toString() DOCUMENT ME!

Methods inherited from class java.lang.Object

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

Constructor Detail

Heap

public Heap()

Default constructor for Heap(). Creates new heap with 16 elements.

Heap

public Heap(int initialSize)

Alternate constructor for heap that allows specification of initial size.

Parameters:

initialSize -

Method Detail

add

public void add(java.lang.Comparable c)

Adds new element to the heap.

Parameters:

c - Element to add.

remove

public java.lang.Comparable remove()

Removes smallest element.

Returns:

Element or null if empty.

get

public java.lang.Comparable get(int index)

Returns element at index.

Parameters:

index - Index of the element.

Returns:

synchronized

size

public int size()

Size of the heap.

Returns:

synchronized

isEmpty

public boolean isEmpty()

True if heap is empty.

Returns:

synchronized

getFirst

public java.lang.Comparable getFirst()

Returns smallest element or null if empty.

Returns:

synchronized

toString

public java.lang.String toString()

DOCUMENT ME!

Overrides:

toString in class java.lang.Object

Returns:

DOCUMENT ME!

main

public static void main(java.lang.String[] args)

Run test applet.

Parameters:

args - command line parameters