de.lmu.ifi.dbs.elki.utilities.datastructures.heap

Class DoubleMinHeap

java.lang.Object

de.lmu.ifi.dbs.elki.utilities.datastructures.heap.DoubleMinHeap

All Implemented Interfaces:

DoubleHeap

public class DoubleMinHeap
extends Object
implements DoubleHeap

Binary heap for primitive types.

Author:

Erich Schubert

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private class	DoubleMinHeap.UnsortedIter Unsorted iterator - in heap order.

Field Summary

Fields

Modifier and Type	Field and Description
protected int	size Current size of heap.
private static int	TWO_HEAP_INITIAL_SIZE Initial size of the 2-ary heap.
protected double[]	twoheap Base heap.

Constructor Summary

Constructors

Constructor and Description
DoubleMinHeap() Constructor, with default size.
DoubleMinHeap(int minsize) Constructor, with given minimum size.

Method Summary

Methods

Modifier and Type	Method and Description
void	add(double o) Add a key-value pair to the heap
void	add(double key, int max) Add a key-value pair to the heap, except if the new element is larger than the top, and we are at design size (overflow)
void	clear() Delete all elements from the heap.
private void	heapifyDown(double cur) Invoke heapify-down for the root object.
private void	heapifyUp(int twopos, double cur) Heapify-Up method for 2-ary heap.
boolean	isEmpty() Is the heap empty?
double	peek() Get the current top key
double	poll() Remove the first element
double	replaceTopElement(double reinsert) Combined operation that removes the top element, and inserts a new element instead.
int	size() Query the size
String	toString()
DoubleMinHeap.UnsortedIter	unsortedIter() Get an unsorted iterator to inspect the heap.

Methods inherited from class java.lang.Object

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

Field Detail

twoheap

protected double[] twoheap

Base heap.

size

protected int size

Current size of heap.

TWO_HEAP_INITIAL_SIZE

private static final int TWO_HEAP_INITIAL_SIZE

Initial size of the 2-ary heap.

See Also:

Constant Field Values

Constructor Detail

DoubleMinHeap

public DoubleMinHeap()

Constructor, with default size.

DoubleMinHeap

public DoubleMinHeap(int minsize)

Constructor, with given minimum size.

Parameters:

minsize - Minimum size

Method Detail

clear

public void clear()

Description copied from interface: DoubleHeap

Delete all elements from the heap.

Specified by:

clear in interface DoubleHeap

size

public int size()

Description copied from interface: DoubleHeap

Query the size

Specified by:

size in interface DoubleHeap

Returns:

Size

isEmpty

public boolean isEmpty()

Description copied from interface: DoubleHeap

Is the heap empty?

Specified by:

isEmpty in interface DoubleHeap

Returns:

true when the size is 0.

add

public void add(double o)

Description copied from interface: DoubleHeap

Add a key-value pair to the heap

Specified by:

add in interface DoubleHeap

Parameters:

o - Key

add

public void add(double key,
       int max)

Description copied from interface: DoubleHeap

Add a key-value pair to the heap, except if the new element is larger than the top, and we are at design size (overflow)

Specified by:

add in interface DoubleHeap

Parameters:

key - Key

max - Maximum size of heap

replaceTopElement

public double replaceTopElement(double reinsert)

Description copied from interface: DoubleHeap

Combined operation that removes the top element, and inserts a new element instead.

Specified by:

replaceTopElement in interface DoubleHeap

Parameters:

reinsert - New element to insert

Returns:

Previous top element of the heap

heapifyUp

private void heapifyUp(int twopos,
             double cur)

Heapify-Up method for 2-ary heap.

Parameters:

twopos - Position in 2-ary heap.

cur - Current object

poll

public double poll()

Description copied from interface: DoubleHeap

Remove the first element

Specified by:

poll in interface DoubleHeap

Returns:

Top element

heapifyDown

private void heapifyDown(double cur)

Invoke heapify-down for the root object.

Parameters:

cur - Object to insert.

peek

public double peek()

Description copied from interface: DoubleHeap

Get the current top key

Specified by:

peek in interface DoubleHeap

Returns:

Top key

toString

public String toString()

Overrides:

toString in class Object

unsortedIter

public DoubleMinHeap.UnsortedIter unsortedIter()

Description copied from interface: DoubleHeap

Get an unsorted iterator to inspect the heap.

Specified by:

unsortedIter in interface DoubleHeap

Returns:

Iterator