net.automatalib.commons.util

Class UnionFindRemSP

java.lang.Object

net.automatalib.commons.util.UnionFindRemSP

All Implemented Interfaces:

IntDisjointSets

public class UnionFindRemSP
extends Object
implements IntDisjointSets

Implementation of a disjoint set (union-find) data structure for integers, based on Rem's algorithm, as described in the paper Experiments on Union-Find Algorithms for the Disjoint-Set Data Structure (M. Patwary, J. Blair, F. Manne; Proc. SEA 2010).

Author:

Malte Isberner

Constructor Summary

Constructors

Constructor and Description
UnionFindRemSP(int n) Initializes the disjoint-set data structure.

Method Summary

Modifier and Type	Method and Description
boolean	equivalent(int x, int y) Checks if two elements are in the same set.
int	find(int x) Finds the set of a given element, and compresses the path to the root node.
int	link(int x, int y) Unites two given sets.
int	size() Returns the size of the universe.
boolean	union(int x, int y) Unites the sets containing the two given elements.

Methods inherited from class java.lang.Object

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

Constructor Detail

UnionFindRemSP

public UnionFindRemSP(int n)

Initializes the disjoint-set data structure.

Parameters:

n - the overall size of the domain

Method Detail

size

public int size()

Description copied from interface: IntDisjointSets

Returns the size of the universe. The elements of the universe are the integers between 0 (inclusive) and size() (exclusive).

Specified by:

size in interface IntDisjointSets

Returns:

the size of the universe

equivalent

public boolean equivalent(int x,
                          int y)

Description copied from interface: IntDisjointSets

Checks if two elements are in the same set.

Specified by:

equivalent in interface IntDisjointSets

Parameters:

x - the first element

y - the second element

Returns:

true if x and y are in the same set, false otherwise

find

public int find(int x)

Finds the set of a given element, and compresses the path to the root node.

Specified by:

find in interface IntDisjointSets

Parameters:

x - the element

Returns:

the identifier of the set which contains the given element

union

public boolean union(int x,
                     int y)

Unites the sets containing the two given elements.

Specified by:

union in interface IntDisjointSets

Parameters:

x - the first element

y - the second element

Returns:

true if two disjoint sets have been united as a result, false otherwise

link

public int link(int x,
                int y)

Unites two given sets. Note that the behavior of this method is not specified if the given parameters are normal elements and no set identifiers.

Specified by:

link in interface IntDisjointSets

Parameters:

x - the first set

y - the second set

Returns:

the identifier of the resulting set (either x or y)