org.anc.util

Class SparseArray<T>

java.lang.Object

org.anc.util.SparseArray<T>

All Implemented Interfaces:

Iterable<T>

public class SparseArray<T>
extends Object
implements Iterable<T>

Experimental.

An array/vector like data structure with a large capacity, that is a large maximum index, but that is expected to be mostly empty. For example, an array with space for one million elements but that will only ever contain a few hundred items.

This implementation uses two a data structures to provide the backing store for the sparse array. A SkipList to provide efficient linear access to the elements of the array, and a Hashtable to provide efficient random access to the elements of the array.

NOTE: The iterator returned by a call to method iterator() iterates over the items present in the array and not the individual array elements. For example, the following only prints two items even though the array is 1,000 elements "long".

     SparseArray array = new SparseArray();
     array.setElementAt(0, "Hello");
     arrar.setElementAt(999, "World");
     for (String s : array)
     {
         System.out.println(s);
     }
 

Version:

1.0

Author:

Keith Suderman

Constructor Summary

Constructors

Constructor and Description
SparseArray()

Method Summary

Modifier and Type	Method and Description
void	clear()
T	getElementAt(long index)
long	getMaxIndex()
Iterator<T>	iterator()
static void	main(String[] args)
void	setElementAt(long index, T value)
long	size()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

SparseArray

public SparseArray()

Method Detail

setElementAt

public void setElementAt(long index,
                         T value)

getElementAt

public T getElementAt(long index)

size

public long size()

getMaxIndex

public long getMaxIndex()

clear

public void clear()

iterator

public Iterator<T> iterator()

Specified by:

iterator in interface Iterable<T>

main

public static void main(String[] args)