org._3pq.jgrapht.alg

Class CycleDetector


public class CycleDetector
extends java.lang.Object

Performs cycle detection on a graph. The inspected graph is specified at construction time and cannot be modified. Currently, the detector supports only directed graphs.
Author:
John V. Sichi
Since:
Sept 16, 2004

Constructor Summary

CycleDetector(DirectedGraph graph)
Creates a cycle detector for the specified graph.

Method Summary

boolean
detectCycles()
Performs yes/no cycle detection on the entire graph.
boolean
detectCyclesContainingVertex(Object v)
Performs yes/no cycle detection on an individual vertex.
Set
findCycles()
Finds the vertex set for the subgraph of all cycles.
Set
findCyclesContainingVertex(Object v)
Finds the vertex set for the subgraph of all cycles which contain a particular vertex.

Constructor Details

CycleDetector

public CycleDetector(DirectedGraph graph)
Creates a cycle detector for the specified graph. Currently only directed graphs are supported.
Parameters:
graph - the DirectedGraph in which to detect cycles

Method Details

detectCycles

public boolean detectCycles()
Performs yes/no cycle detection on the entire graph.
Returns:
true iff the graph contains at least one cycle

detectCyclesContainingVertex

public boolean detectCyclesContainingVertex(Object v)
Performs yes/no cycle detection on an individual vertex.
Parameters:
v - the vertex to test
Returns:
true if v is on at least one cycle

findCycles

public Set findCycles()
Finds the vertex set for the subgraph of all cycles.
Returns:
set of all vertices which participate in at least one cycle in this graph

findCyclesContainingVertex

public Set findCyclesContainingVertex(Object v)
Finds the vertex set for the subgraph of all cycles which contain a particular vertex.
Parameters:
v - the vertex to test
Returns:
set of all vertices reachable from v via at least one cycle