org.jgrapht.alg.vertexcover

Class ClarksonTwoApproxVCImpl<V,E>

java.lang.Object

org.jgrapht.alg.vertexcover.ClarksonTwoApproxVCImpl<V,E>

Type Parameters:

V - the graph vertex type

E - the graph edge type

All Implemented Interfaces:

MinimumVertexCoverAlgorithm<V,E>, MinimumWeightedVertexCoverAlgorithm<V,E>, VertexCoverAlgorithm<V>

public class ClarksonTwoApproxVCImpl<V,E>
extends Object
implements MinimumWeightedVertexCoverAlgorithm<V,E>, VertexCoverAlgorithm<V>

Implementation of the 2-opt algorithm for a minimum weighted vertex cover by Clarkson, Kenneth L. "A modification of the greedy algorithm for vertex cover." Information Processing Letters 16.1 (1983): 23-25. The solution is guaranteed to be within $2$ times the optimum solution. Runtime: $O(|E|\log |V|)$ Note: this class supports pseudo-graphs

Author:

Joris Kinable

Nested Class Summary

Nested classes/interfaces inherited from interface org.jgrapht.alg.interfaces.MinimumVertexCoverAlgorithm

MinimumVertexCoverAlgorithm.VertexCover<V>, MinimumVertexCoverAlgorithm.VertexCoverImpl<V>

Nested classes/interfaces inherited from interface org.jgrapht.alg.interfaces.VertexCoverAlgorithm

VertexCoverAlgorithm.VertexCover<V>, VertexCoverAlgorithm.VertexCoverImpl<V>

Constructor Summary

Constructors

Constructor and Description
ClarksonTwoApproxVCImpl() Deprecated. this constructor will be removed in the next release
ClarksonTwoApproxVCImpl(Graph<V,E> graph) Constructs a new ClarksonTwoApproxVCImpl instance where all vertices have uniform weights.
ClarksonTwoApproxVCImpl(Graph<V,E> graph, Map<V,Double> vertexWeightMap) Constructs a new ClarksonTwoApproxVCImpl instance

Method Summary

Modifier and Type	Method and Description
VertexCoverAlgorithm.VertexCover<V>	getVertexCover() Computes a vertex cover.
MinimumVertexCoverAlgorithm.VertexCover<V>	getVertexCover(Graph<V,E> graph, Map<V,Double> vertexWeightMap) Deprecated. Replaced by getVertexCover()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.jgrapht.alg.interfaces.MinimumWeightedVertexCoverAlgorithm

getVertexCover

Constructor Detail

ClarksonTwoApproxVCImpl

@Deprecated
public ClarksonTwoApproxVCImpl()

Deprecated. this constructor will be removed in the next release

Temporary constructor to ensure one-version-backwards-compatibility

ClarksonTwoApproxVCImpl

public ClarksonTwoApproxVCImpl(Graph<V,E> graph)

Constructs a new ClarksonTwoApproxVCImpl instance where all vertices have uniform weights.

Parameters:

graph - input graph

ClarksonTwoApproxVCImpl

public ClarksonTwoApproxVCImpl(Graph<V,E> graph,
                               Map<V,Double> vertexWeightMap)

Constructs a new ClarksonTwoApproxVCImpl instance

Parameters:

graph - input graph

vertexWeightMap - mapping of vertex weights

Method Detail

getVertexCover

public VertexCoverAlgorithm.VertexCover<V> getVertexCover()

Description copied from interface: VertexCoverAlgorithm

Computes a vertex cover.

Specified by:

getVertexCover in interface VertexCoverAlgorithm<V>

Returns:

a vertex cover

getVertexCover

@Deprecated
public MinimumVertexCoverAlgorithm.VertexCover<V> getVertexCover(Graph<V,E> graph,
                                                                             Map<V,Double> vertexWeightMap)

Deprecated. Replaced by getVertexCover()

Description copied from interface: MinimumWeightedVertexCoverAlgorithm

Computes a vertex cover; the weight of each vertex is provided in the in the vertexWeightMap.

Specified by:

getVertexCover in interface MinimumWeightedVertexCoverAlgorithm<V,E>

Parameters:

graph - the input graph

vertexWeightMap - map containing non-negative weights for each vertex

Returns:

vertex cover