private void GenerateSpanningTree()
{
_spanningTree = new BidirectionalGraph <TVertex, Edge <TVertex> >(false);
_spanningTree.AddVertexRange(VisitedGraph.Vertices);
IQueue <TVertex> vb = new QuickGraph.Collections.Queue <TVertex>();
if (VisitedGraph.VertexCount > 0)
{
vb.Enqueue(VisitedGraph.Vertices.OrderBy(v => VisitedGraph.InDegree(v)).First());
}
switch (Parameters.SpanningTreeGeneration)
{
case SpanningTreeGeneration.BFS:
var bfsAlgo = new BreadthFirstSearchAlgorithm <TVertex, TEdge>(VisitedGraph, vb, new Dictionary <TVertex, GraphColor>());
bfsAlgo.TreeEdge += e => _spanningTree.AddEdge(new Edge <TVertex>(e.Source, e.Target));
bfsAlgo.Compute();
break;
case SpanningTreeGeneration.DFS:
var dfsAlgo = new DepthFirstSearchAlgorithm <TVertex, TEdge>(VisitedGraph);
dfsAlgo.TreeEdge += e => _spanningTree.AddEdge(new Edge <TVertex>(e.Source, e.Target));
dfsAlgo.Compute();
break;
}
}
/// <summary>
/// Computes the maximum flow between Source and Sink.
/// </summary>
/// <returns></returns>
protected override void InternalCompute()
{
if (this.Source == null)
{
throw new InvalidOperationException("Source is not specified");
}
if (this.Sink == null)
{
throw new InvalidOperationException("Sink is not specified");
}
if (this.Services.CancelManager.IsCancelling)
{
return;
}
var g = this.VisitedGraph;
foreach (var u in g.Vertices)
{
foreach (var e in g.OutEdges(u))
{
var capacity = this.Capacities(e);
if (capacity < 0)
{
throw new InvalidOperationException("negative edge capacity");
}
this.ResidualCapacities[e] = capacity;
}
}
this.VertexColors[Sink] = GraphColor.Gray;
while (this.VertexColors[Sink] != GraphColor.White)
{
var vis = new VertexPredecessorRecorderObserver <TVertex, TEdge>(
this.Predecessors
);
var queue = new QuickGraph.Collections.Queue <TVertex>();
var bfs = new BreadthFirstSearchAlgorithm <TVertex, TEdge>(
this.ResidualGraph,
queue,
this.VertexColors
);
using (vis.Attach(bfs))
bfs.Compute(this.Source);
if (this.VertexColors[this.Sink] != GraphColor.White)
{
this.Augment(this.Source, this.Sink);
}
} // while
this.MaxFlow = 0;
foreach (var e in g.OutEdges(Source))
{
this.MaxFlow += (this.Capacities(e) - this.ResidualCapacities[e]);
}
}
/// <summary>
/// Computes the maximum flow between <paramref name="src"/> and
/// <paramref name="sink"/>
/// </summary>
/// <param name="src"></param>
/// <param name="sink"></param>
/// <returns></returns>
protected override void InternalCompute()
{
if (this.Source == null)
{
throw new InvalidOperationException("Source is not specified");
}
if (this.Sink == null)
{
throw new InvalidOperationException("Sink is not specified");
}
foreach (TVertex u in VisitedGraph.Vertices)
{
foreach (TEdge e in VisitedGraph.OutEdges(u))
{
ResidualCapacities[e] = Capacities[e];
}
}
VertexColors[Sink] = GraphColor.Gray;
while (VertexColors[Sink] != GraphColor.White)
{
VertexPredecessorRecorderObserver <TVertex, TEdge> vis = new VertexPredecessorRecorderObserver <TVertex, TEdge>(
Predecessors
);
var Q = new QuickGraph.Collections.Queue <TVertex>();
var bfs = new BreadthFirstSearchAlgorithm <TVertex, TEdge>(
ResidualGraph,
Q,
VertexColors
);
vis.Attach(bfs);
bfs.Compute(this.Source);
vis.Detach(bfs);
if (VertexColors[this.Sink] != GraphColor.White)
{
Augment(this.Source, this.Sink);
}
} // while
this.MaxFlow = 0;
foreach (TEdge e in VisitedGraph.OutEdges(Source))
{
this.MaxFlow += (Capacities[e] - ResidualCapacities[e]);
}
}
private BidirectionalGraph <FrameworkElement, Edge> GenerateSpanningTree(BidirectionalGraph <FrameworkElement, Edge> graph)
{
var spanningTree = new BidirectionalGraph <FrameworkElement, Edge>(false);
spanningTree.AddVertexRange(graph.Vertices.ToList());
IQueue <FrameworkElement> vb = new QuickGraph.Collections.Queue <FrameworkElement>();
vb.Enqueue(graph.Vertices.OrderBy(graph.InDegree).First());
//switch (Parameters.SpanningTreeGeneration)
//{
// case SpanningTreeGeneration.BFS:
var bfsAlgo = new DepthFirstSearchAlgorithm <FrameworkElement, Edge>(graph);
bfsAlgo.TreeEdge += e => spanningTree.AddEdge(e);
bfsAlgo.Compute();
// break;
// case SpanningTreeGeneration.DFS:
// var dfsAlgo = new DepthFirstSearchAlgorithm<TVertex, TEdge>(VisitedGraph);
// dfsAlgo.TreeEdge += e => spanningTree.AddEdge(new Edge<TVertex>(e.Source, e.Target));
// dfsAlgo.Compute();
// break;
//}
return(spanningTree);
}
