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

Class DoubleObjectMaxHeap<V>

java.lang.Object

de.lmu.ifi.dbs.elki.utilities.datastructures.heap.DoubleObjectMaxHeap<V>

Type Parameters:

V - Value type

All Implemented Interfaces:

DoubleObjectHeap<V>

public class DoubleObjectMaxHeap<V>
extends Object
implements DoubleObjectHeap<V>

Binary heap for primitive types.

Author:

Erich Schubert

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private class	DoubleObjectMaxHeap.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.
protected Object[]	twovals Base heap values.

Constructor Summary

Constructors

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

Method Summary

Methods

Modifier and Type	Method and Description
void	add(double o, V v) Add a key-value pair to the heap
void	add(double key, V val, int max) Add a key-value pair to the heap if it improves the top.
void	clear() Clear the heap contents.
private void	heapifyDown(double cur, Object val) Invoke heapify-down for the root object.
private void	heapifyUp(int twopos, double cur, Object val) Heapify-Up method for 2-ary heap.
boolean	isEmpty() Is the heap empty?
double	peekKey() Get the current top key
V	peekValue() Get the current top value
void	poll() Remove the first element
void	replaceTopElement(double reinsert, V val) Combined operation that removes the top element, and inserts a new element instead.
int	size() Query the size
String	toString()
DoubleObjectMaxHeap.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.

twovals

protected Object[] twovals

Base heap values.

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

DoubleObjectMaxHeap

public DoubleObjectMaxHeap()

Constructor, with default size.

DoubleObjectMaxHeap

public DoubleObjectMaxHeap(int minsize)

Constructor, with given minimum size.

Parameters:

minsize - Minimum size

Method Detail

clear

public void clear()

Description copied from interface: DoubleObjectHeap

Clear the heap contents.

Specified by:

clear in interface DoubleObjectHeap<V>

size

public int size()

Description copied from interface: DoubleObjectHeap

Query the size

Specified by:

size in interface DoubleObjectHeap<V>

Returns:

Size

isEmpty

public boolean isEmpty()

Description copied from interface: DoubleObjectHeap

Is the heap empty?

Specified by:

isEmpty in interface DoubleObjectHeap<V>

Returns:

true when the size is 0.

add

public void add(double o,
       V v)

Description copied from interface: DoubleObjectHeap

Add a key-value pair to the heap

Specified by:

add in interface DoubleObjectHeap<V>

Parameters:

o - Key

v - Value

add

public void add(double key,
       V val,
       int max)

Description copied from interface: DoubleObjectHeap

Add a key-value pair to the heap if it improves the top.

Specified by:

add in interface DoubleObjectHeap<V>

Parameters:

key - Key

val - Value

max - Desired maximum size

replaceTopElement

public void replaceTopElement(double reinsert,
                     V val)

Description copied from interface: DoubleObjectHeap

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

Specified by:

replaceTopElement in interface DoubleObjectHeap<V>

Parameters:

reinsert - Key of new element

val - Value of new element

heapifyUp

private void heapifyUp(int twopos,
             double cur,
             Object val)

Heapify-Up method for 2-ary heap.

Parameters:

twopos - Position in 2-ary heap.

cur - Current object

val - Current value

poll

public void poll()

Description copied from interface: DoubleObjectHeap

Remove the first element

Specified by:

poll in interface DoubleObjectHeap<V>

heapifyDown

private void heapifyDown(double cur,
               Object val)

Invoke heapify-down for the root object.

Parameters:

cur - Object to insert.

val - Value to reinsert.

peekKey

public double peekKey()

Description copied from interface: DoubleObjectHeap

Get the current top key

Specified by:

peekKey in interface DoubleObjectHeap<V>

Returns:

Top key

peekValue

public V peekValue()

Description copied from interface: DoubleObjectHeap

Get the current top value

Specified by:

peekValue in interface DoubleObjectHeap<V>

Returns:

Value

toString

public String toString()

Overrides:

toString in class Object

unsortedIter

public DoubleObjectMaxHeap.UnsortedIter unsortedIter()

Description copied from interface: DoubleObjectHeap

Get an unsorted iterator to inspect the heap.

Specified by:

unsortedIter in interface DoubleObjectHeap<V>

Returns:

Iterator