/// <summary> Constructs a minimum cycle basis of a graph.
///
/// </summary>
/// <param name="g">the graph for the cycle basis
/// </param>
public CycleBasis(UndirectedGraph g)
{
baseGraph = g;
// We construct a simple graph out of the input (multi-)graph
// as a subgraph with no multiedges.
// The removed edges are collected in multiEdgeList
// Moreover, shortest cycles through these edges are constructed and
// collected in mulitEdgeCycles
UndirectedGraph simpleGraph = new UndirectedSubgraph(g, null, null);
// Iterate over the edges and discard all edges with the same source and target
//UPGRADE_TODO: Method 'java.util.Iterator.hasNext' was converted to 'System.Collections.IEnumerator.MoveNext' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javautilIteratorhasNext'"
for (System.Collections.IEnumerator it = g.edgeSet().GetEnumerator(); it.MoveNext();)
{
//UPGRADE_TODO: Method 'java.util.Iterator.next' was converted to 'System.Collections.IEnumerator.Current' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javautilIteratornext'"
Edge edge = (Edge)((DictionaryEntry)it.Current).Value;
System.Object u = edge.Source;
System.Object v = edge.Target;
System.Collections.IList edges = simpleGraph.getAllEdges(u, v);
if (edges.Count > 1)
{
// Multiple edges between u and v.
// Keep the edge with the least weight
Edge minEdge = edge;
//UPGRADE_TODO: Method 'java.util.Iterator.hasNext' was converted to 'System.Collections.IEnumerator.MoveNext' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javautilIteratorhasNext'"
for (System.Collections.IEnumerator jt = edges.GetEnumerator(); jt.MoveNext();)
{
//UPGRADE_TODO: Method 'java.util.Iterator.next' was converted to 'System.Collections.IEnumerator.Current' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javautilIteratornext'"
Edge nextEdge = (Edge)jt.Current;
minEdge = nextEdge.Weight < minEdge.Weight ? nextEdge : minEdge;
}
// ...and remove the others.
//UPGRADE_TODO: Method 'java.util.Iterator.hasNext' was converted to 'System.Collections.IEnumerator.MoveNext' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javautilIteratorhasNext'"
for (System.Collections.IEnumerator jt = edges.GetEnumerator(); jt.MoveNext();)
{
//UPGRADE_TODO: Method 'java.util.Iterator.next' was converted to 'System.Collections.IEnumerator.Current' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javautilIteratornext'"
Edge nextEdge = (Edge)jt.Current;
if (nextEdge != minEdge)
{
// Remove edge from the graph
simpleGraph.removeEdge(nextEdge);
// Create a new cycle through this edge by finding
// a shortest path between the vertices of the edge
//UPGRADE_TODO: Class 'java.util.HashSet' was converted to 'CSGraphT.SupportClass.HashSetSupport' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javautilHashSet'"
CSGraphT.SupportClass.SetSupport edgesOfCycle = new CSGraphT.SupportClass.HashSetSupport();
edgesOfCycle.Add(nextEdge);
edgesOfCycle.AddAll(DijkstraShortestPath.findPathBetween(simpleGraph, u, v));
multiEdgeList.Add(nextEdge);
mulitEdgeCycles.Add(new SimpleCycle(baseGraph, edgesOfCycle));
}
}
}
}
System.Collections.IList biconnectedComponents = new BiconnectivityInspector(simpleGraph).biconnectedSets();
for (IEnumerator it = biconnectedComponents.GetEnumerator(); it.MoveNext();)
{
CSGraphT.SupportClass.SetSupport edges = (CSGraphT.SupportClass.SetSupport)it.Current;
//IList edges = (IList)it.Current;
if (edges.Count > 1)
{
CSGraphT.SupportClass.SetSupport vertices = new CSGraphT.SupportClass.HashSetSupport();
for (System.Collections.IEnumerator edgeIt = edges.GetEnumerator(); edgeIt.MoveNext();)
{
Edge edge = (Edge)((DictionaryEntry)edgeIt.Current).Value;
vertices.Add(edge.Source);
vertices.Add(edge.Target);
}
UndirectedGraph subgraph = new UndirectedSubgraph(simpleGraph, vertices, edges);
SimpleCycleBasis cycleBasis = new SimpleCycleBasis(subgraph);
subgraphBases.Add(cycleBasis);
}
else
{
Edge edge = (Edge)((DictionaryEntry)edges.GetEnumerator().Current).Value;
multiEdgeList.Add(edge);
}
}
}
private System.Collections.IList lazyFindBiconnectedSets()
{
if (biconnectedSets_Renamed_Field == null)
{
biconnectedSets_Renamed_Field = new System.Collections.ArrayList();
IList inspector = new ConnectivityInspector(graph).connectedSets();
System.Collections.IEnumerator connectedSets = inspector.GetEnumerator();
while (connectedSets.MoveNext())
{
object obj = ((DictionaryEntry)connectedSets.Current).Value;
if (!(obj is CSGraphT.SupportClass.HashSetSupport))
{
continue;
}
CSGraphT.SupportClass.SetSupport connectedSet = (CSGraphT.SupportClass.SetSupport)obj;
if (connectedSet.Count == 1)
{
continue;
}
org._3pq.jgrapht.Graph subgraph = new Subgraph(graph, connectedSet, null);
// do DFS
// Stack for the DFS
System.Collections.ArrayList vertexStack = new System.Collections.ArrayList();
CSGraphT.SupportClass.SetSupport visitedVertices = new CSGraphT.SupportClass.HashSetSupport();
IDictionary parent = new System.Collections.Hashtable();
IList dfsVertices = new System.Collections.ArrayList();
CSGraphT.SupportClass.SetSupport treeEdges = new CSGraphT.SupportClass.HashSetSupport();
System.Object currentVertex = subgraph.vertexSet()[0];//.ToArray()[0];
vertexStack.Add(currentVertex);
visitedVertices.Add(currentVertex);
while (!(vertexStack.Count == 0))
{
currentVertex = SupportClass.StackSupport.Pop(vertexStack);
System.Object parentVertex = parent[currentVertex];
if (parentVertex != null)
{
Edge edge = subgraph.getEdge(parentVertex, currentVertex);
// tree edge
treeEdges.Add(edge);
}
visitedVertices.Add(currentVertex);
dfsVertices.Add(currentVertex);
System.Collections.IEnumerator edges = subgraph.edgesOf(currentVertex).GetEnumerator();
while (edges.MoveNext())
{
// find a neighbour vertex of the current vertex
Edge edge = (Edge)edges.Current;
if (!treeEdges.Contains(edge))
{
System.Object nextVertex = edge.oppositeVertex(currentVertex);
if (!visitedVertices.Contains(nextVertex))
{
vertexStack.Add(nextVertex);
parent[nextVertex] = currentVertex;
}
else
{
// non-tree edge
}
}
}
}
// DFS is finished. Now create the auxiliary graph h
// Add all the tree edges as vertices in h
SimpleGraph h = new SimpleGraph();
h.addAllVertices(treeEdges);
visitedVertices.Clear();
CSGraphT.SupportClass.SetSupport connected = new CSGraphT.SupportClass.HashSetSupport();
for (System.Collections.IEnumerator it = dfsVertices.GetEnumerator(); it.MoveNext();)
{
System.Object v = it.Current;
visitedVertices.Add(v);
// find all adjacent non-tree edges
for (System.Collections.IEnumerator adjacentEdges = subgraph.edgesOf(v).GetEnumerator(); adjacentEdges.MoveNext();)
{
Edge l = (Edge)adjacentEdges.Current;
if (!treeEdges.Contains(l))
{
h.addVertex(l);
System.Object u = l.oppositeVertex(v);
// we need to check if (u,v) is a back-edge
if (!visitedVertices.Contains(u))
{
while (u != v)
{
System.Object pu = parent[u];
Edge f = subgraph.getEdge(u, pu);
h.addEdge(f, l);
if (!connected.Contains(f))
{
connected.Add(f);
u = pu;
}
else
{
u = v;
}
}
}
}
}
}
ConnectivityInspector connectivityInspector = new ConnectivityInspector(h);
biconnectedSets_Renamed_Field.Add(connectivityInspector.connectedSets());
}
}
return(biconnectedSets_Renamed_Field);
}
