private static double RunMaxFlowAlgorithm <TVertex, TEdge>(IMutableVertexAndEdgeListGraph <TVertex, TEdge> g, EdgeFactory <TVertex, TEdge> edgeFactory, TVertex source, TVertex sink) where TEdge : IEdge <TVertex>
{
TryFunc <TVertex, TEdge> flowPredecessors;
var flow = AlgorithmExtensions.MaximumFlowEdmondsKarp <TVertex, TEdge>(
g,
e => 1,
source, sink,
out flowPredecessors,
edgeFactory
);
return(flow);
}
public void UsagePresentation()
{
int verticesCount = 10;
int edgesCount = 40;
var vertices = new V[verticesCount];
for (int i = 0; i < verticesCount; i++)
{
vertices[i] = new V()
{
Name = Path.GetRandomFileName().Substring(0, 5)
}
}
;
var graph = new AdjacencyGraph <V, E>();
graph.AddVertexRange(vertices);
graph.AddEdgeRange(Enumerable.Range(1, edgesCount)
.Select(i => new E()
{
Cost = rand.Next(100), Source = vertices[rand.Next(verticesCount)], Target = vertices[rand.Next(verticesCount)]
}));
foreach (var v in graph.Vertices)
{
Console.WriteLine(v);
foreach (var edge in graph.OutEdges(v))
{
Console.WriteLine(edge);
}
}
// Visualisation
//var g = graph.ToIdentifiableGleeGraph(a => a.Name, null, null);
//var viewer = new GViewer() { Graph = g };
//viewer.Parent = this;
//viewer.Dock = DockStyle.Fill;
// ------ Dijkstra
var dijkstra = new DijkstraShortestPathAlgorithm <V, E>(graph, e => e.Cost);
dijkstra.Compute(vertices[0]);
Console.WriteLine(string.Join(", ", dijkstra.Distances.Select(d => string.Format("{0}: {1}", d.Key, d.Value))));
// ------ Maximum Flow
// we need a graph, a source and a sink
V source = vertices[0];
V sink = vertices[9];
// A function with maps an edge to its capacity
Func <E, double> capacityFunc = (edge => edge.Cost);
// A function which takes a vertex and returns the edge connecting to its predecessor in the flow network
TryFunc <V, E> flowPredecessors;
// A function used to create new edges during the execution of the algorithm. These edges are removed before the computation returns
EdgeFactory <V, E> edgeFactory = (s, t) => new E {
Source = s, Target = t
};
// computing the maximum flow using Edmonds Karp.
double flow = AlgorithmExtensions.MaximumFlowEdmondsKarp <V, E>(
graph,
capacityFunc,
source, sink,
out flowPredecessors,
edgeFactory);
Console.WriteLine(flow);
}
}