it.uniroma3.mat.extendedset.intset

Class FastSet

java.lang.Object

it.uniroma3.mat.extendedset.intset.AbstractIntSet

it.uniroma3.mat.extendedset.intset.FastSet

All Implemented Interfaces:

IntSet, Serializable, Cloneable, Comparable<IntSet>

public class FastSet
extends AbstractIntSet
implements Serializable

An IntSet implementation, representing a set of integers, based on an uncompressed bitmap.

It actually is an extension of BitSet. More specifically, union and intersection operations are mainly derived from the code of BitSet to provide bitwise "or" and "and".

The iterator implemented for this class allows for modifications during the iteration, that is it is possible to add/remove elements through add(int), remove(int), addAll(IntSet), removeAll(IntSet), retainAll(IntSet), etc.. In this case, IntSet.IntIterator.next() returns the first integral greater than the last visited one.

Version:

$Id$

Author:

Alessandro Colantonio

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface it.uniroma3.mat.extendedset.intset.IntSet

IntSet.IntIterator

Constructor Summary

Constructors

Constructor and Description
FastSet() Creates a new, empty set.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	add(int i) Adds the specified element to this set if it is not already present.
boolean	addAll(IntSet c) Adds all of the elements in the specified collection to this set if they're not already present.
double	bitmapCompressionRatio() Computes the compression factor of the equivalent bitmap representation (1 means not compressed, namely a memory footprint similar to BitSet, 2 means twice the size of BitSet, etc.)
void	clear() Removes all of the elements from this set.
void	clear(int fromIndex, int toIndex) Removes from the set all the elements between first and last, both included.
FastSet	clone() See the clone() of Object
double	collectionCompressionRatio() Computes the compression factor of the equivalent integer collection (1 means not compressed, namely a memory footprint similar to ArrayList, 2 means twice the size of ArrayList, etc.)
int	compareTo(IntSet o)
void	complement() Complements the current set.
FastSet	complemented() Generates the complement set.
boolean	contains(int i) Returns true if this set contains the specified element.
boolean	containsAll(IntSet c) Returns true if this set contains all of the elements of the specified collection.
boolean	containsAny(IntSet c) Returns true if the specified IntSet instance contains any elements that are also contained within this IntSet instance
boolean	containsAtLeast(IntSet c, int minElements) Returns true if the specified IntSet instance contains at least minElements elements that are also contained within this IntSet instance
FastSet	convert(Collection<Integer> c) Converts a given collection into an instance of the current class.
FastSet	convert(int... a) Converts a given array into an instance of the current class.
String	debugInfo() Prints debug info about the given IntSet implementation
IntSet.IntIterator	descendingIterator()
FastSet	difference(IntSet other) Generates the difference set
FastSet	empty() Generates an empty set
boolean	equals(Object obj)
void	fill(int fromIndex, int toIndex) Adds to the set all the elements between first and last, both included.
void	flip(int e) Adds the element if it not existing, or removes it if existing
int	get(int index) Gets the ith element of the set
int	hashCode()
int	indexOf(int e) Provides position of element within the set.
FastSet	intersection(IntSet other) Generates the intersection set
int	intersectionSize(IntSet c) Computes the intersection set size.
boolean	isEmpty()
IntSet.IntIterator	iterator()
int	last() Returns the last (highest) element currently in this set.
boolean	remove(int i) Removes the specified element from this set if it is present.
boolean	removeAll(IntSet c) Removes from this set all of its elements that are contained in the specified collection.
boolean	retainAll(IntSet c) Retains only the elements in this set that are contained in the specified collection.
int	size()
FastSet	symmetricDifference(IntSet other) Generates the symmetric difference set
FastSet	union(IntSet other) Generates the union set

Methods inherited from class it.uniroma3.mat.extendedset.intset.AbstractIntSet

complementSize, differenceSize, first, jaccardDistance, jaccardSimilarity, powerSet, powerSet, powerSetSize, powerSetSize, symmetricDifferenceSize, toArray, toArray, toString, unionSize, weightedJaccardDistance, weightedJaccardSimilarity

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

FastSet

public FastSet()

Creates a new, empty set.

Method Detail

clone

public FastSet clone()

See the clone() of Object

Specified by:

clone in interface IntSet

Specified by:

clone in class AbstractIntSet

Returns:

cloned object

hashCode

public int hashCode()

Overrides:

hashCode in class AbstractIntSet

equals

public boolean equals(Object obj)

Overrides:

equals in class AbstractIntSet

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface IntSet

Specified by:

isEmpty in class AbstractIntSet

Returns:

true if this set contains no elements

size

public int size()

Specified by:

size in interface IntSet

Specified by:

size in class AbstractIntSet

Returns:

the number of elements in this set (its cardinality)

add

public boolean add(int i)

Adds the specified element to this set if it is not already present. It ensures that sets never contain duplicate elements.

Specified by:

add in interface IntSet

Specified by:

add in class AbstractIntSet

Parameters:

i - element to be added to this set

Returns:

true if this set did not already contain the specified element

remove

public boolean remove(int i)

Removes the specified element from this set if it is present.

Specified by:

remove in interface IntSet

Specified by:

remove in class AbstractIntSet

Parameters:

i - object to be removed from this set, if present

Returns:

true if this set contained the specified element

addAll

public boolean addAll(IntSet c)

Adds all of the elements in the specified collection to this set if they're not already present.

Specified by:

addAll in interface IntSet

Overrides:

addAll in class AbstractIntSet

Parameters:

c - collection containing elements to be added to this set

Returns:

true if this set changed as a result of the call

See Also:

IntSet.add(int)

removeAll

public boolean removeAll(IntSet c)

Removes from this set all of its elements that are contained in the specified collection.

Specified by:

removeAll in interface IntSet

Overrides:

removeAll in class AbstractIntSet

Parameters:

c - collection containing elements to be removed from this set

Returns:

true if this set changed as a result of the call

See Also:

IntSet.remove(int), IntSet.contains(int)

retainAll

public boolean retainAll(IntSet c)

Retains only the elements in this set that are contained in the specified collection. In other words, removes from this set all of its elements that are not contained in the specified collection.

Specified by:

retainAll in interface IntSet

Overrides:

retainAll in class AbstractIntSet

Parameters:

c - collection containing elements to be retained in this set

Returns:

true if this set changed as a result of the call

See Also:

IntSet.remove(int)

clear

public void clear()

Removes all of the elements from this set. The set will be empty after this call returns.

Specified by:

clear in interface IntSet

Overrides:

clear in class AbstractIntSet

contains

public boolean contains(int i)

Returns true if this set contains the specified element.

Specified by:

contains in interface IntSet

Specified by:

contains in class AbstractIntSet

Parameters:

i - element whose presence in this set is to be tested

Returns:

true if this set contains the specified element

containsAll

public boolean containsAll(IntSet c)

Returns true if this set contains all of the elements of the specified collection.

Specified by:

containsAll in interface IntSet

Overrides:

containsAll in class AbstractIntSet

Parameters:

c - collection to be checked for containment in this set

Returns:

true if this set contains all of the elements of the specified collection

See Also:

IntSet.contains(int)

containsAtLeast

public boolean containsAtLeast(IntSet c,
                      int minElements)

Returns true if the specified IntSet instance contains at least minElements elements that are also contained within this IntSet instance

Specified by:

containsAtLeast in interface IntSet

Overrides:

containsAtLeast in class AbstractIntSet

Parameters:

c - IntSet instance to intersect with

minElements - minimum number of elements to be contained within this IntSet instance

Returns:

a boolean indicating whether this IntSet intersects the specified IntSet.

containsAny

public boolean containsAny(IntSet c)

Returns true if the specified IntSet instance contains any elements that are also contained within this IntSet instance

Specified by:

containsAny in interface IntSet

Overrides:

containsAny in class AbstractIntSet

Parameters:

c - IntSet to intersect with

Returns:

a boolean indicating whether this IntSet intersects the specified IntSet.

intersectionSize

public int intersectionSize(IntSet c)

Computes the intersection set size.

This is faster than calling IntSet.intersection(IntSet) and then IntSet.size()

Specified by:

intersectionSize in interface IntSet

Overrides:

intersectionSize in class AbstractIntSet

Parameters:

c - IntSet instance that represents the right operand

Returns:

the size

iterator

public IntSet.IntIterator iterator()

Specified by:

iterator in interface IntSet

Specified by:

iterator in class AbstractIntSet

Returns:

a IntSet.IntIterator instance to iterate over the set

descendingIterator

public IntSet.IntIterator descendingIterator()

Specified by:

descendingIterator in interface IntSet

Specified by:

descendingIterator in class AbstractIntSet

Returns:

a IntSet.IntIterator instance to iterate over the set in descending order

last

public int last()

Returns the last (highest) element currently in this set.

Specified by:

last in interface IntSet

Specified by:

last in class AbstractIntSet

Returns:

the last (highest) element currently in this set

complement

public void complement()

Complements the current set. The modified set is represented by all the elements strictly less than IntSet.last() that do not exist in the current set.

Specified by:

complement in interface IntSet

Overrides:

complement in class AbstractIntSet

See Also:

IntSet.complemented()

complemented

public FastSet complemented()

Generates the complement set. The returned set is represented by all the elements strictly less than IntSet.last() that do not exist in the current set.

Specified by:

complemented in interface IntSet

Overrides:

complemented in class AbstractIntSet

Returns:

the complement set

See Also:

IntSet.complement()

empty

public FastSet empty()

Generates an empty set

Specified by:

empty in interface IntSet

Specified by:

empty in class AbstractIntSet

Returns:

the empty set

bitmapCompressionRatio

public double bitmapCompressionRatio()

Computes the compression factor of the equivalent bitmap representation (1 means not compressed, namely a memory footprint similar to BitSet, 2 means twice the size of BitSet, etc.)

Specified by:

bitmapCompressionRatio in interface IntSet

Specified by:

bitmapCompressionRatio in class AbstractIntSet

Returns:

the compression factor

collectionCompressionRatio

public double collectionCompressionRatio()

Computes the compression factor of the equivalent integer collection (1 means not compressed, namely a memory footprint similar to ArrayList, 2 means twice the size of ArrayList, etc.)

Specified by:

collectionCompressionRatio in interface IntSet

Specified by:

collectionCompressionRatio in class AbstractIntSet

Returns:

the compression factor

convert

public FastSet convert(Collection<Integer> c)

Converts a given collection into an instance of the current class.

Specified by:

convert in interface IntSet

Specified by:

convert in class AbstractIntSet

Parameters:

c - array to use to generate the new instance

Returns:

the converted collection

convert

public FastSet convert(int... a)

Converts a given array into an instance of the current class.

Specified by:

convert in interface IntSet

Specified by:

convert in class AbstractIntSet

Parameters:

a - array to use to generate the new instance

Returns:

the converted collection

fill

public void fill(int fromIndex,
        int toIndex)

Adds to the set all the elements between first and last, both included.

Specified by:

fill in interface IntSet

Overrides:

fill in class AbstractIntSet

Parameters:

fromIndex - first element

toIndex - last element

clear

public void clear(int fromIndex,
         int toIndex)

Removes from the set all the elements between first and last, both included.

Specified by:

clear in interface IntSet

Overrides:

clear in class AbstractIntSet

Parameters:

fromIndex - first element

toIndex - last element

flip

public void flip(int e)

Adds the element if it not existing, or removes it if existing

Specified by:

flip in interface IntSet

Overrides:

flip in class AbstractIntSet

Parameters:

e - element to flip

See Also:

IntSet.symmetricDifference(IntSet)

compareTo

public int compareTo(IntSet o)

Specified by:

compareTo in interface Comparable<IntSet>

Overrides:

compareTo in class AbstractIntSet

get

public int get(int index)

Gets the i^th element of the set

Specified by:

get in interface IntSet

Specified by:

get in class AbstractIntSet

Parameters:

index - position of the element in the sorted set

Returns:

the i^th element of the set

indexOf

public int indexOf(int e)

Provides position of element within the set.

It returns -1 if the element does not exist within the set.

Specified by:

indexOf in interface IntSet

Specified by:

indexOf in class AbstractIntSet

Parameters:

e - element of the set

Returns:

the element position

intersection

public FastSet intersection(IntSet other)

Generates the intersection set

Specified by:

intersection in interface IntSet

Overrides:

intersection in class AbstractIntSet

Parameters:

other - IntSet instance that represents the right operand

Returns:

the result of the operation

See Also:

IntSet.retainAll(IntSet)

union

public FastSet union(IntSet other)

Generates the union set

Specified by:

union in interface IntSet

Overrides:

union in class AbstractIntSet

Parameters:

other - IntSet instance that represents the right operand

Returns:

the result of the operation

See Also:

IntSet.addAll(IntSet)

difference

public FastSet difference(IntSet other)

Generates the difference set

Specified by:

difference in interface IntSet

Overrides:

difference in class AbstractIntSet

Parameters:

other - IntSet instance that represents the right operand

Returns:

the result of the operation

See Also:

IntSet.removeAll(IntSet)

symmetricDifference

public FastSet symmetricDifference(IntSet other)

Generates the symmetric difference set

Specified by:

symmetricDifference in interface IntSet

Overrides:

symmetricDifference in class AbstractIntSet

Parameters:

other - IntSet instance that represents the right operand

Returns:

the result of the operation

See Also:

IntSet.flip(int)

debugInfo

public String debugInfo()

Prints debug info about the given IntSet implementation

Specified by:

debugInfo in interface IntSet

Specified by:

debugInfo in class AbstractIntSet

Returns:

a string that describes the internal representation of the instance