/// <summary>
/// Compute the condensation graph and store it in the supplied graph 'cg'
/// </summary>
/// <param name="cg">
/// Instance of mutable graph in which the condensation graph
/// transformation is stored
/// </param>
public void Create( IMutableVertexAndEdgeListGraph cg )
{
if (cg==null)
throw new ArgumentNullException("cg");
if (components==null)
ComputeComponents();
// components list contains collection of
// input graph Vertex for each SCC Vertex_ID
// (i.e Vector< Vector<Vertex> > )
// Key = SCC Vertex ID
sccVertexMap = BuildSCCVertexMap(components);
// Lsit of SCC vertices
VertexCollection toCgVertices = new VertexCollection();
IDictionaryEnumerator it = sccVertexMap.GetEnumerator();
while( it.MoveNext() )
// as scc_vertex_map is a sorted list, order of SCC IDs will match CG vertices
{
IVertex curr = cg.AddVertex();
OnInitCondensationGraphVertex(new CondensationGraphVertexEventArgs(curr, (IVertexCollection)it.Value));
toCgVertices.Add(curr);
}
for( int srcSccId=0; srcSccId<sccVertexMap.Keys.Count; srcSccId++ )
{
VertexCollection adj = new VertexCollection();
foreach( IVertex u in (IVertexCollection)sccVertexMap[srcSccId] )
{
foreach(IEdge e in VisitedGraph.OutEdges(u)) {
IVertex v = e.Target;
int targetSccId = components[v];
if (srcSccId != targetSccId)
{
// Avoid loops in the condensation graph
IVertex sccV = toCgVertices[targetSccId];
if( !adj.Contains(sccV) ) // Avoid parallel edges
adj.Add(sccV);
}
}
}
IVertex s = toCgVertices[srcSccId];
foreach( IVertex t in adj )
cg.AddEdge(s, t);
}
}
/// <summary>
/// Create a collection of odd vertices
/// </summary>
/// <param name="g">graph to visit</param>
/// <returns>colleciton of odd vertices</returns>
/// <exception cref="ArgumentNullException">g is a null reference</exception>
public static VertexCollection OddVertices(IVertexAndEdgeListGraph g)
{
if (g==null)
throw new ArgumentNullException("g");
VertexIntDictionary counts = new VertexIntDictionary();
foreach(IVertex v in g.Vertices)
{
counts[v]=0;
}
foreach(IEdge e in g.Edges)
{
++counts[e.Source];
--counts[e.Target];
}
VertexCollection odds= new VertexCollection();
foreach(DictionaryEntry de in counts)
{
if ((int)de.Value%2!=0)
odds.Add((IVertex)de.Key);
}
return odds;
}
private SortedList BuildSCCVertexMap( VertexIntDictionary vSccMap )
{
// Construct a map of SCC ID as key & IVertexCollection of vertices contained within the SCC as value
SortedList h = new SortedList();
VertexCollection vertices = null;
foreach( DictionaryEntry de in vSccMap )
{
IVertex v = (IVertex) de.Key;
int scc_id = (int) de.Value;
if( h.ContainsKey(scc_id) )
((VertexCollection) h[scc_id]).Add(v);
else
{
vertices = new VertexCollection();
vertices.Add(v);
h.Add(scc_id, vertices);
}
}
return h;
}
public void Create(IMutableVertexAndEdgeListGraph cg)
{
if (cg == null)
{
throw new ArgumentNullException("cg");
}
if (this.components == null)
{
this.ComputeComponents();
}
this.sccVertexMap = this.BuildSCCVertexMap(this.components);
VertexCollection vertexs = new VertexCollection();
IDictionaryEnumerator enumerator = this.sccVertexMap.GetEnumerator();
while (enumerator.MoveNext())
{
IVertex cgVertex = cg.AddVertex();
this.OnInitCondensationGraphVertex(new CondensationGraphVertexEventArgs(cgVertex, (IVertexCollection) enumerator.Value));
vertexs.Add(cgVertex);
}
for (int i = 0; i < this.sccVertexMap.Keys.Count; i++)
{
VertexCollection vertexs2 = new VertexCollection();
IVertexEnumerator enumerator2 = ((IVertexCollection) this.sccVertexMap[i]).GetEnumerator();
while (enumerator2.MoveNext())
{
IVertex vertex2 = enumerator2.get_Current();
IEdgeEnumerator enumerator3 = this.VisitedGraph.OutEdges(vertex2).GetEnumerator();
while (enumerator3.MoveNext())
{
IVertex vertex3 = enumerator3.get_Current().get_Target();
int num2 = this.components.get_Item(vertex3);
if (i != num2)
{
IVertex vertex4 = vertexs.get_Item(num2);
if (!vertexs2.Contains(vertex4))
{
vertexs2.Add(vertex4);
}
}
}
}
IVertex vertex5 = vertexs.get_Item(i);
VertexCollection.Enumerator enumerator4 = vertexs2.GetEnumerator();
while (enumerator4.MoveNext())
{
IVertex vertex6 = enumerator4.get_Current();
cg.AddEdge(vertex5, vertex6);
}
}
}
private SortedList BuildSCCVertexMap(VertexIntDictionary vSccMap)
{
SortedList list = new SortedList();
VertexCollection vertexs = null;
IDictionaryEnumerator enumerator = vSccMap.GetEnumerator();
while (enumerator.MoveNext())
{
DictionaryEntry current = (DictionaryEntry) enumerator.Current;
IVertex key = (IVertex) current.Key;
int num = (int) current.Value;
if (list.ContainsKey(num))
{
((VertexCollection) list[num]).Add(key);
}
else
{
vertexs = new VertexCollection();
vertexs.Add(key);
list.Add(num, vertexs);
}
}
return list;
}
/// <summary>
///
/// </summary>
/// <param name="g"></param>
/// <param name="assg"></param>
public void Transform(IBidirectionalGraph g, IMutableVertexAndEdgeListGraph assg)
{
VertexCollection avs = new VertexCollection();
// adding vertices
foreach(IEdge e in g.Edges)
{
// xi_-(L) = g(xi_-(0), xi_+(L))
CharacteristicVertex avm = (CharacteristicVertex)assg.AddVertex();
avm.IncomingEdge = e;
avm.Vertex = e.Target;
avs.Add(avm);
// xi_+(0) = g(xi_-(0), xi_+(L))
CharacteristicVertex avp = (CharacteristicVertex)assg.AddVertex();
avp.IncomingEdge = e;
avp.Vertex = e.Source;
avs.Add(avp);
}
// adding out edges
foreach(CharacteristicVertex av in avs)
{
foreach(IEdge e in g.OutEdges(av.Vertex))
{
// find target vertex:
CharacteristicVertex avtarget = FindTargetVertex(e);
// add xi_-
CharacteristicEdge aem = (CharacteristicEdge)assg.AddEdge(av,avtarget);
aem.Positive = false;
aem.Edge = e;
}
foreach(IEdge e in g.InEdges(av.Vertex))
{
// find target vertex:
CharacteristicVertex avtarget = FindTargetVertex(e);
// add xi_-
CharacteristicEdge aem = (CharacteristicEdge)assg.AddEdge(av,avtarget);
aem.Positive = true;
aem.Edge = e;
}
}
}
/// <summary>
/// Iteratively removes the dangling links from the rank map
/// </summary>
public void RemoveDanglingLinks()
{
VertexCollection danglings = new VertexCollection();
do
{
danglings.Clear();
// create filtered graph
IVertexListGraph fg = new FilteredVertexListGraph(
this.VisitedGraph,
new InDictionaryVertexPredicate(this.ranks)
);
// iterate over of the vertices in the rank map
foreach(IVertex v in this.ranks.Keys)
{
// if v does not have out-edge in the filtered graph, remove
if ( fg.OutDegree(v) == 0)
danglings.Add(v);
}
// remove from ranks
foreach(IVertex v in danglings)
this.ranks.Remove(v);
// iterate until no dangling was removed
}while(danglings.Count != 0);
}
public void RemoveDanglingLinks()
{
VertexCollection vertexs = new VertexCollection();
do
{
vertexs.Clear();
IVertexListGraph graph = new FilteredVertexListGraph(this.VisitedGraph, new InDictionaryVertexPredicate(this.ranks));
foreach (IVertex vertex in this.ranks.get_Keys())
{
if (graph.OutDegree(vertex) == 0)
{
vertexs.Add(vertex);
}
}
VertexCollection.Enumerator enumerator = vertexs.GetEnumerator();
while (enumerator.MoveNext())
{
IVertex vertex2 = enumerator.get_Current();
this.ranks.Remove(vertex2);
}
}
while (vertexs.Count != 0);
}
