/// <summary>
/// Condensation Graph constructor
/// </summary>
/// <param name="g">Input graph from
/// which condensation graph is created</param>
public CondensationGraphAlgorithm(IVertexListGraph g)
{
if (g==null)
throw new ArgumentNullException("g");
this.visitedGraph = g;
this.components = null;
}
/// <summary>
/// Uses the dictionary to record the distance
/// </summary>
/// <param name="distances">Distance dictionary</param>
/// <exception cref="ArgumentNullException">distances is null</exception>
public DistanceRecorderVisitor(VertexIntDictionary distances)
{
if (distances == null)
throw new ArgumentNullException("distances");
m_Distances = distances;
}
/// <summary>
///
/// </summary>
/// <param name="g"></param>
public ConnectedComponentsAlgorithm(IVertexListGraph g)
{
if (g==null)
throw new ArgumentNullException("g");
m_VisitedGraph = g;
m_Components = new VertexIntDictionary();
}
public void ClearComponents()
{
this.components = null;
if (this.sccVertexMap != null)
{
this.sccVertexMap.Clear();
}
}
public PushRelabelMaximumFlowAlgorithm(IIndexedVertexListGraph g, EdgeDoubleDictionary capacities, EdgeEdgeDictionary reversedEdges)
: base(g, capacities, reversedEdges)
{
this.visitedGraph = g;
this.excessFlow = new VertexDoubleDictionary();
this.current = new VertexIntDictionary();
this.distances = new VertexIntDictionary();
}
/// <summary>
///
/// </summary>
/// <param name="g"></param>
public StrongComponentsAlgorithm(IVertexListGraph g)
{
if (g==null)
throw new ArgumentNullException("g");
m_VisitedGraph = g;
m_Components = new VertexIntDictionary();
m_Roots = new VertexVertexDictionary();
m_DiscoverTimes = new VertexIntDictionary();
m_Stack = new Stack();
m_Count = 0;
m_DfsTime = 0;
}
/// <summary>
/// Construct a strong component algorithm
/// </summary>
/// <param name="g">graph to apply algorithm on</param>
/// <exception cref="ArgumentNullException">graph is null</exception>
public StrongComponentsAlgorithm(IVertexListGraph g)
{
if (g==null)
throw new ArgumentNullException("g");
this.visitedGraph = g;
this.components = new VertexIntDictionary();
this.roots = new VertexVertexDictionary();
this.discoverTimes = new VertexIntDictionary();
this.stack = new Stack();
this.count = 0;
this.dfsTime = 0;
}
public ConnectedComponentsAlgorithm(IVertexListGraph g, VertexIntDictionary components)
{
if (g == null)
{
throw new ArgumentNullException("g");
}
if (components == null)
{
throw new ArgumentNullException("components");
}
this.visitedGraph = g;
this.components = components;
}
public void Init()
{
parents = new VertexVertexDictionary();
discoverTimes = new VertexIntDictionary();
finishTimes = new VertexIntDictionary();
time = 0;
g = new BidirectionalGraph(true);
dfs = new UndirectedDepthFirstSearchAlgorithm(g);
dfs.StartVertex += new VertexEventHandler(this.StartVertex);
dfs.DiscoverVertex += new VertexEventHandler(this.DiscoverVertex);
dfs.ExamineEdge += new EdgeEventHandler(this.ExamineEdge);
dfs.TreeEdge += new EdgeEventHandler(this.TreeEdge);
dfs.BackEdge += new EdgeEventHandler(this.BackEdge);
dfs.FinishVertex += new VertexEventHandler(this.FinishVertex);
}
private IVertex FirstNotInChain(ArrayList adj_topo_vertices, VertexIntDictionary vertices_in_a_chain)
{
if (adj_topo_vertices == null)
{
throw new ArgumentNullException("Argument <adj_topo_vertices> in function FirstNotInChain cannot be null");
}
if (adj_topo_vertices.Count != 0)
{
foreach (IVertex vertex in adj_topo_vertices)
{
if (vertices_in_a_chain.get_Item(vertex) == 0)
{
return vertex;
}
}
}
return null;
}
/// <summary>
/// Default constructor
/// </summary>
public DistanceRecorderVisitor()
{
m_Distances = new VertexIntDictionary();
}
protected void Initialize()
{
this.costs = new VertexDoubleDictionary();
this.priorityQueue = new PriorithizedVertexBuffer(this.costs);
this.unvisitedSuccessorCounts = new VertexIntDictionary();
this.states.Clear();
VertexCollection.Enumerator enumerator = this.goals.GetEnumerator();
while (enumerator.MoveNext())
{
IVertex vertex = enumerator.get_Current();
this.costs.Add(vertex, 0.0);
this.priorityQueue.Push(vertex);
}
IVertexEnumerator enumerator2 = this.NotGoals.GetEnumerator();
while (enumerator2.MoveNext())
{
IVertex vertex2 = enumerator2.get_Current();
this.costs.Add(vertex2, double.PositiveInfinity);
}
IVertexEnumerator enumerator3 = this.TestGraph.ChoicePoints.GetEnumerator();
while (enumerator3.MoveNext())
{
IVertex vertex3 = enumerator3.get_Current();
this.unvisitedSuccessorCounts.Add(vertex3, this.testGraph.Graph.OutDegree(vertex3));
}
IVertexEnumerator enumerator4 = this.TestGraph.Graph.get_Vertices().GetEnumerator();
while (enumerator4.MoveNext())
{
IVertex vertex4 = enumerator4.get_Current();
this.states.Add(vertex4, null);
}
}
public CompareTopo(VertexIntDictionary topological_ordering)
{
m_vid = topological_ordering;
}
// return adjacent vertices to "v" sorted in topological order
private ArrayList TopoSortAdjVertices( IVertex v, IIncidenceGraph g, VertexIntDictionary topo_ordering )
{
IEdgeEnumerator it = g.OutEdges(v).GetEnumerator();
bool valid = false;
ArrayList adj = new ArrayList();
while(it.MoveNext()) {
valid = true;
adj.Add(it.Current.Target);
}
if(!valid) // no outgoing edges
return adj;
CompareTopo ctopo = new CompareTopo(topo_ordering);
SwapTopo stopo = new SwapTopo();
QuickSorter qs = new QuickSorter(ctopo, stopo);
qs.Sort(adj);
return adj;
}
internal void ComputeComponents()
{
if (this.components == null)
{
this.components = new VertexIntDictionary();
}
new StrongComponentsAlgorithm(this.VisitedGraph, this.components).Compute();
}
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;
}
private bool IsOptimal(MaximumFlowAlgorithm maxFlow)
{
// check if mincut is saturated...
FilteredVertexListGraph residualGraph = new FilteredVertexListGraph(
maxFlow.VisitedGraph,
new ReversedResidualEdgePredicate(maxFlow.ResidualCapacities, maxFlow.ReversedEdges)
);
BreadthFirstSearchAlgorithm bfs = new BreadthFirstSearchAlgorithm(residualGraph);
VertexIntDictionary distances = new VertexIntDictionary();
DistanceRecorderVisitor vis = new DistanceRecorderVisitor(distances);
bfs.RegisterDistanceRecorderHandlers(vis);
bfs.Compute(sink);
return distances[source] >= maxFlow.VisitedGraph.VerticesCount;
}
/// <summary>
/// Computes the strong components.
/// </summary>
/// <remarks>
/// <para>
/// Thread safe.
/// </para>
/// </remarks>
/// <param name="g">graph to explore</param>
/// <param name="components">component map where results are recorded</param>
/// <returns>number of strong components</returns>
public static int StrongComponents(
IVertexListGraph g,
VertexIntDictionary components)
{
StrongComponentsAlgorithm strong =
new StrongComponentsAlgorithm(g,components);
return strong.Compute();
}
private IVertex FirstNotInChain( ArrayList adj_topo_vertices, VertexIntDictionary vertices_in_a_chain )
// Return the first adjacent vertex which is not already present in any of the chains
{
if(adj_topo_vertices == null)
throw new ArgumentNullException("Argument <adj_topo_vertices> in function FirstNotInChain cannot be null");
if( adj_topo_vertices.Count == 0 )
return null;
foreach( IVertex v in adj_topo_vertices )
if(vertices_in_a_chain[v] == 0)
return v;
return null;
}
public void Create(IMutableVertexAndEdgeListGraph tc)
{
if (tc == null)
{
throw new ArgumentNullException("tc");
}
CondensationGraphAlgorithm algorithm = new CondensationGraphAlgorithm(this.VisitedGraph);
algorithm.Create(this.cg);
ArrayList vertices = new ArrayList(this.cg.get_VerticesCount());
new TopologicalSortAlgorithm(this.cg, vertices).Compute();
VertexIntDictionary dictionary = new VertexIntDictionary();
VertexIntDictionary dictionary2 = new VertexIntDictionary();
for (int i = 0; i < vertices.Count; i++)
{
IVertex vertex = (IVertex) vertices[i];
dictionary2.Add(vertex, i);
if (!dictionary.Contains(vertex))
{
dictionary.Add(vertex, 0);
}
}
VertexListMatrix chains = new VertexListMatrix();
int num2 = -1;
Label_0112:
foreach (IVertex vertex2 in vertices)
{
if (dictionary.get_Item(vertex2) == 0)
{
num2 = chains.AddRow();
IVertex vertex3 = vertex2;
while (true)
{
chains[num2].Add(vertex3);
dictionary.set_Item(vertex3, 1);
ArrayList list2 = this.TopoSortAdjVertices(vertex3, this.cg, dictionary2);
vertex3 = this.FirstNotInChain(list2, dictionary);
if (vertex3 == null)
{
goto Label_0112;
}
}
}
}
VertexIntDictionary dictionary3 = new VertexIntDictionary();
VertexIntDictionary dictionary4 = new VertexIntDictionary();
this.SetChainPositions(chains, dictionary3, dictionary4);
VertexListMatrix matrix2 = new VertexListMatrix();
matrix2.CreateObjectMatrix(this.cg.get_VerticesCount(), chains.RowCount, 0x7fffffff);
if (vertices.Count > 0)
{
for (int j = vertices.Count - 1; j > -1; j--)
{
IVertex v = (IVertex) vertices[j];
foreach (IVertex vertex5 in this.TopoSortAdjVertices(v, this.cg, dictionary2))
{
if (dictionary2.get_Item(vertex5) < ((int) matrix2[v.get_ID()][dictionary3.get_Item(vertex5)]))
{
this.LeftUnion(matrix2[v.get_ID()], matrix2[vertex5.get_ID()]);
matrix2[v.get_ID()][dictionary3.get_Item(vertex5)] = dictionary2.get_Item(vertex5);
}
}
}
}
ArrayList list3 = new ArrayList();
IEdgeEnumerator enumerator = this.cg.get_Edges().GetEnumerator();
while (enumerator.MoveNext())
{
IEdge edge = enumerator.get_Current();
list3.Add(edge);
}
foreach (IEdge edge2 in list3)
{
this.cg.RemoveEdge(edge2);
}
IVertexEnumerator enumerator5 = this.cg.get_Vertices().GetEnumerator();
while (enumerator5.MoveNext())
{
IVertex vertex6 = enumerator5.get_Current();
int num4 = vertex6.get_ID();
for (int k = 0; k < chains.RowCount; k++)
{
int num6 = (int) matrix2[num4][k];
if (num6 < 0x7fffffff)
{
IVertex vertex7 = (IVertex) vertices[num6];
for (int m = dictionary4.get_Item(vertex7); m < chains[k].Count; m++)
{
this.cg.AddEdge(vertex6, (IVertex) chains[k][m]);
}
}
}
}
this.graphTransitiveClosures = new VertexVertexDictionary();
IVertexEnumerator enumerator6 = this.visitedGraph.get_Vertices().GetEnumerator();
while (enumerator6.MoveNext())
{
IVertex vertex8 = enumerator6.get_Current();
if (!this.graphTransitiveClosures.Contains(vertex8))
{
IVertex vertex9 = tc.AddVertex();
this.OnInitTransitiveClosureVertex(new TransitiveClosureVertexEventArgs(vertex8, vertex9));
this.graphTransitiveClosures.Add(vertex8, vertex9);
}
}
IVertexCollection vertexs = null;
IVertexEnumerator enumerator7 = this.cg.get_Vertices().GetEnumerator();
while (enumerator7.MoveNext())
{
IVertex vertex10 = enumerator7.get_Current();
vertexs = (IVertexCollection) algorithm.SCCVerticesMap[vertex10.get_ID()];
if (vertexs.Count > 1)
{
IVertexEnumerator enumerator8 = vertexs.GetEnumerator();
while (enumerator8.MoveNext())
{
IVertex vertex11 = enumerator8.get_Current();
IVertexEnumerator enumerator9 = vertexs.GetEnumerator();
while (enumerator9.MoveNext())
{
IVertex vertex12 = enumerator9.get_Current();
this.OnExamineEdge(tc.AddEdge(this.graphTransitiveClosures.get_Item(vertex11), this.graphTransitiveClosures.get_Item(vertex12)));
}
}
}
IEdgeEnumerator enumerator10 = this.cg.OutEdges(vertex10).GetEnumerator();
while (enumerator10.MoveNext())
{
IVertex vertex13 = enumerator10.get_Current().get_Target();
IVertexEnumerator enumerator11 = ((IVertexCollection) algorithm.SCCVerticesMap[vertex10.get_ID()]).GetEnumerator();
while (enumerator11.MoveNext())
{
IVertex vertex14 = enumerator11.get_Current();
IVertexEnumerator enumerator12 = ((IVertexCollection) algorithm.SCCVerticesMap[vertex13.get_ID()]).GetEnumerator();
while (enumerator12.MoveNext())
{
IVertex vertex15 = enumerator12.get_Current();
this.OnExamineEdge(tc.AddEdge(this.graphTransitiveClosures.get_Item(vertex14), this.graphTransitiveClosures.get_Item(vertex15)));
}
}
}
}
}
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;
}
private ArrayList TopoSortAdjVertices(IVertex v, IIncidenceGraph g, VertexIntDictionary topo_ordering)
{
IEdgeEnumerator enumerator = g.OutEdges(v).GetEnumerator();
bool flag = false;
ArrayList list = new ArrayList();
while (enumerator.MoveNext())
{
flag = true;
list.Add(enumerator.get_Current().get_Target());
}
if (flag)
{
CompareTopo topo = new CompareTopo(topo_ordering);
SwapTopo topo2 = new SwapTopo();
new QuickSorter(topo, topo2).Sort(list);
}
return list;
}
/// <summary>
/// Computes the connected components.
/// </summary>
/// <param name="g">graph to explore</param>
/// <param name="components">component map where results are recorded</param>
/// <returns>number of components</returns>
public static int ConnectedComponents(
IVertexListGraph g,
VertexIntDictionary components)
{
ConnectedComponentsAlgorithm conn =
new ConnectedComponentsAlgorithm(g,components);
return conn.Compute();
}
/// <summary>
/// Default constructor
/// </summary>
public TimeStamperVisitor()
{
m_DiscoverTimes = new VertexIntDictionary();
m_FinishTimes = new VertexIntDictionary();
m_Time = 0;
}
/// <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;
}
/// <summary>
/// Compute the transitive closure and store it in the supplied graph 'tc'
/// </summary>
/// <param name="tc">
/// Mutable Graph instance to store the transitive closure
/// </param>
/// <exception cref="ArgumentNullException">
/// <paramref name="tc"/> is a <null/>.
/// </exception>
public void Create( IMutableVertexAndEdgeListGraph tc )
{
if (tc==null)
throw new ArgumentNullException("tc");
CondensationGraphAlgorithm cgalgo = new CondensationGraphAlgorithm(VisitedGraph);
cgalgo.Create(cg);
ArrayList topo_order = new ArrayList(cg.VerticesCount);
TopologicalSortAlgorithm topo = new TopologicalSortAlgorithm(cg, topo_order);
topo.Compute();
VertexIntDictionary in_a_chain= new VertexIntDictionary();
VertexIntDictionary topo_number = new VertexIntDictionary();
for( int order=0; order<topo_order.Count; order++ ) {
IVertex v = (IVertex)topo_order[order];
topo_number.Add( v, order );
if(!in_a_chain.Contains(v)) // Initially no vertex is present in a chain
in_a_chain.Add(v, 0);
}
VertexListMatrix chains = new VertexListMatrix();
int position = -1;
foreach( IVertex v in topo_order )
{
if(in_a_chain[v]==0) {
// Start a new chain
position = chains.AddRow();
IVertex next = v;
for(;;) {
chains[position].Add(next);
in_a_chain[next] = 1;
// Get adjacent vertices ordered by topological number
// Extend the chain by choosing the adj vertex with lowest topo#
ArrayList adj = TopoSortAdjVertices(next, cg, topo_number);
if( (next = FirstNotInChain(adj, in_a_chain)) == null )
break;
}
}
}
VertexIntDictionary chain_number = new VertexIntDictionary();
VertexIntDictionary pos_in_chain = new VertexIntDictionary();
// Record chain positions of vertices
SetChainPositions(chains, chain_number, pos_in_chain);
VertexListMatrix successors = new VertexListMatrix();
successors.CreateObjectMatrix(cg.VerticesCount, chains.RowCount, int.MaxValue);
if(topo_order.Count > 0)
{
for( int rtopo=topo_order.Count-1; rtopo>-1; rtopo--)
{
IVertex u = (IVertex) topo_order[rtopo];
foreach( IVertex v in TopoSortAdjVertices(u, cg, topo_number) )
{
if(topo_number[v] < (int)successors[u.ID][chain_number[v]])
{
// {succ(u)} = {succ(u)} U {succ(v)}
LeftUnion(successors[u.ID], successors[v.ID]);
// {succ(u)} = {succ(u)} U {v}
successors[u.ID][chain_number[v]] = topo_number[v];
}
}
}
}
// Create transitive closure of condensation graph
// Remove existing edges in CG & rebuild edges for TC from
// successor set (to avoid duplicating parallel edges)
ArrayList edges = new ArrayList();
foreach( IEdge e in cg.Edges )
edges.Add(e);
foreach(IEdge e in edges)
cg.RemoveEdge(e);
foreach(IVertex u in cg.Vertices)
{
int i = u.ID;
for(int j=0; j<chains.RowCount; j++)
{
int tnumber = (int) successors[i][j];
if(tnumber < int.MaxValue)
{
IVertex v = (IVertex) topo_order[tnumber];
for(int k=pos_in_chain[v]; k<chains[j].Count; k++)
{
cg.AddEdge( u, (IVertex)chains[j][k]);
}
}
}
}
// Maps a vertex in input graph to it's transitive closure graph
graphTransitiveClosures = new VertexVertexDictionary();
// Add vertices to transitive closure graph
foreach(IVertex v in visitedGraph.Vertices)
{
if(!graphTransitiveClosures.Contains(v))
{
IVertex vTransform = tc.AddVertex();
OnInitTransitiveClosureVertex(
new TransitiveClosureVertexEventArgs(
v, vTransform)
);
// Fire the TC Vertex Event
graphTransitiveClosures.Add(v, vTransform);
}
}
//Add edges connecting vertices within SCC & adjacent
// SCC (strongly connected component)
IVertexCollection scc_vertices = null;
foreach(IVertex s_tccg in cg.Vertices)
{
scc_vertices = (IVertexCollection)cgalgo.SCCVerticesMap[s_tccg.ID];
if(scc_vertices.Count > 1)
{
foreach(IVertex u in scc_vertices)
foreach(IVertex v in scc_vertices)
OnExamineEdge(tc.AddEdge(graphTransitiveClosures[u], graphTransitiveClosures[v]));
}
foreach(IEdge adj_edge in cg.OutEdges(s_tccg))
{
IVertex t_tccg = adj_edge.Target;
foreach(IVertex s in (IVertexCollection)cgalgo.SCCVerticesMap[s_tccg.ID])
{
foreach(IVertex t in (IVertexCollection)cgalgo.SCCVerticesMap[t_tccg.ID])
OnExamineEdge(tc.AddEdge(graphTransitiveClosures[s], graphTransitiveClosures[t]));
}
}
}
}
internal void ComputeComponents()
{
if( components == null )
components = new VertexIntDictionary();
// components is a MAP containing vertex number as key & component_id as value. It maps every vertex in input graph to SCC vertex ID which contains it
StrongComponentsAlgorithm algo = new StrongComponentsAlgorithm(
VisitedGraph,
this.components
);
algo.Compute();
}
// Return the first adjacent vertex which is not already present in any of the chains
private IVertex FirstNotInChain( ArrayList adj_topo_vertices, VertexIntDictionary vertices_in_a_chain )
{
if(adj_topo_vertices == null)
throw new ArgumentNullException("Argument <adj_topo_vertices> in function FirstNotInChain cannot be null");
if( adj_topo_vertices.Count == 0 )
return null;
foreach( IVertex v in adj_topo_vertices )
if(vertices_in_a_chain[v] == 0)
return v;
return null;
}
private void menuItem8_Click(object sender, System.EventArgs e)
{
if (this.netronPanel.Graph==null)
throw new Exception("Generate a graph first");
if (this.netronPanel.Populator==null)
throw new Exception("Populator should not be null.");
ResetVertexAndEdgeColors();
// create algorithm
this.vertexCounts = new VertexIntDictionary();
this.edgeCounts = new EdgeIntDictionary();
foreach(IVertex vertex in this.netronPanel.Graph.Vertices)
this.vertexCounts[vertex]=0;
foreach(IEdge edge in this.netronPanel.Graph.Edges)
this.edgeCounts[edge]=0;
this.edgeWeights =new EdgeDoubleDictionary();
foreach(IEdge edge in this.netronPanel.Graph.Edges)
edgeWeights[edge]=1;
WeightedMarkovEdgeChain chain = new WeightedMarkovEdgeChain(edgeWeights);
RandomWalkAlgorithm walker = new RandomWalkAlgorithm(
this.netronPanel.Graph
);
walker.TreeEdge+=new EdgeEventHandler(walker_WeightedTreeEdge);
LayoutAlgorithmTraverVisitor tracer = new LayoutAlgorithmTraverVisitor(this.netronPanel.Populator);
walker.TreeEdge +=new EdgeEventHandler(tracer.TreeEdge);
Thread thread = new Thread(new ThreadStart(walker.Generate));
thread.Start();
}
// Record chain number and position in chain of each vertex in chains
private void SetChainPositions( VertexListMatrix chains, VertexIntDictionary chain_number, VertexIntDictionary pos_in_chain )
{
if (chain_number == null)
throw new ArgumentNullException("chain_number");
if (pos_in_chain == null)
throw new ArgumentNullException("pos_in_chain");
for(int i=0; i<chains.RowCount; i++) {
for( int j=0;j<chains[i].Count; j++) {
IVertex v = (IVertex) chains[i][j];
if(! chain_number.ContainsKey(v))
chain_number.Add(v, i);
if(! pos_in_chain.ContainsKey(v))
pos_in_chain.Add(v,j);
}
}
}
