salvo.jesus.graph.algorithm

Class CycleDetectionAlgorithmDFS

java.lang.Object

salvo.jesus.graph.algorithm.CycleDetectionAlgorithm

salvo.jesus.graph.algorithm.CycleDetectionAlgorithmDFS

public class CycleDetectionAlgorithmDFS
extends CycleDetectionAlgorithm

An implementation of CycleDetectionAlgorithm via DFS. Although the interface declares parameters of type Graph, only DirectedGraphs are currently supported.

Author:

John V. Sichi

Field Summary

Fields inherited from class salvo.jesus.graph.algorithm.CycleDetectionAlgorithm

m_graph

Constructor Summary

Constructors

Constructor and Description
CycleDetectionAlgorithmDFS(Graph graph)

Method Summary

Modifier and Type	Method and Description
boolean	detectCycles() Perform cycle detection on the entire graph.
boolean	detectCycles(Edge e) Determine whether an individual edge is on a cycle.
boolean	detectCycles(Vertex v) Determine whether an individual vertex is on a cycle.
void	findCycleSubgraph(Graph subgraph) Find the subgraph of all cycles.
void	findCycleSubgraph(Graph subgraph, Edge e) Find the subgraph of all cycles which contain a particular edge.
void	findCycleSubgraph(Graph subgraph, Vertex v) Find the subgraph of all cycles which contain a particular vertex.

Methods inherited from class java.lang.Object

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

Constructor Detail

CycleDetectionAlgorithmDFS

public CycleDetectionAlgorithmDFS(Graph graph)

Method Detail

findCycleSubgraph

public void findCycleSubgraph(Graph subgraph)
                       throws Exception

Description copied from class: CycleDetectionAlgorithm

Find the subgraph of all cycles. The result is written into an existing graph rather than returned in a new graph; this leaves the caller control over the representation to use for the subgraph.

Specified by:

findCycleSubgraph in class CycleDetectionAlgorithm

Parameters:

subgraph - an output parameter which receives the subgraph of all vertices and edges which participate in cycles; on entry, should be empty

Throws:

Exception - if subgraph.addEdge fails

See Also:

CycleDetectionAlgorithm.findCycleSubgraph(Graph)

findCycleSubgraph

public void findCycleSubgraph(Graph subgraph,
                              Vertex v)
                       throws Exception

Description copied from class: CycleDetectionAlgorithm

Find the subgraph of all cycles which contain a particular vertex. The result is written into an existing graph rather than returned in a new graph; this leaves the caller control over the representation to use for the subgraph.

Specified by:

findCycleSubgraph in class CycleDetectionAlgorithm

Parameters:

subgraph - an output parameter which receives the subgraph of all vertices and edges which participate in cycles containing v; on entry, should be empty

v - the vertex to test

Throws:

Exception - if subgraph.addEdge fails

See Also:

CycleDetectionAlgorithm.findCycleSubgraph(Graph,Vertex)

findCycleSubgraph

public void findCycleSubgraph(Graph subgraph,
                              Edge e)
                       throws Exception

Description copied from class: CycleDetectionAlgorithm

Find the subgraph of all cycles which contain a particular edge. The result is written into an existing graph rather than returned in a new graph; this leaves the caller control over the representation to use for the subgraph.

Specified by:

findCycleSubgraph in class CycleDetectionAlgorithm

Parameters:

subgraph - an output parameter which receives the subgraph of all vertices and edges which participate in cycles containing e; on entry, should be empty

e - the edge to test

Throws:

Exception - if subgraph.addEdge fails

See Also:

CycleDetectionAlgorithm.findCycleSubgraph(Graph,Edge)

detectCycles

public boolean detectCycles()

Description copied from class: CycleDetectionAlgorithm

Perform cycle detection on the entire graph.

Specified by:

detectCycles in class CycleDetectionAlgorithm

Returns:

true iff the graph contains at least one cycle

See Also:

CycleDetectionAlgorithm.detectCycles()

detectCycles

public boolean detectCycles(Vertex v)

Description copied from class: CycleDetectionAlgorithm

Determine whether an individual vertex is on a cycle.

Specified by:

detectCycles in class CycleDetectionAlgorithm

Parameters:

v - the vertex to test

Returns:

true if v is on at least one cycle

See Also:

CycleDetectionAlgorithm.detectCycles(Vertex)

detectCycles

public boolean detectCycles(Edge e)

Description copied from class: CycleDetectionAlgorithm

Determine whether an individual edge is on a cycle.

Specified by:

detectCycles in class CycleDetectionAlgorithm

Parameters:

e - the edge to test

Returns:

true if e is on at least one cycle

See Also:

CycleDetectionAlgorithm.detectCycles(Edge)