public void Repro42450()
{
var ug = new UndirectedGraph <object, Edge <object> >(true);
object v1 = "vertex1";
object v2 = "vertex2";
object v3 = "vertex3";
var e1 = new Edge <object>(v1, v2);
var e2 = new Edge <object>(v2, v3);
var e3 = new Edge <object>(v3, v1);
ug.AddVertex(v1);
ug.AddVertex(v2);
ug.AddVertex(v3);
ug.AddEdge(e1);
ug.AddEdge(e2);
ug.AddEdge(e3);
var udspa =
new UndirectedDijkstraShortestPathAlgorithm <object, QuickGraph.Edge <object> >(ug, edge => (double)1);
var observer =
new UndirectedVertexPredecessorRecorderObserver <object, Edge <object> >();
using (observer.Attach(udspa))
udspa.Compute(v1);
IEnumerable <QuickGraph.Edge <object> > path;
observer.TryGetPath(v3, out path);
}
private void UndirectedDijkstra <TVertex, TEdge>(IUndirectedGraph <TVertex, TEdge> g, TVertex root)
where TEdge : IEdge <TVertex>
{
var distances = new Dictionary <TEdge, double>();
foreach (var e in g.Edges)
{
distances[e] = g.AdjacentDegree(e.Source) + 1;
}
var algo = new UndirectedDijkstraShortestPathAlgorithm <TVertex, TEdge>(
g,
e => distances[e]
);
var predecessors = new UndirectedVertexPredecessorRecorderObserver <TVertex, TEdge>();
using (predecessors.Attach(algo))
algo.Compute(root);
Verify(algo, predecessors);
}
private static void Verify <TVertex, TEdge>(
UndirectedDijkstraShortestPathAlgorithm <TVertex, TEdge> algo,
UndirectedVertexPredecessorRecorderObserver <TVertex, TEdge> predecessors)
where TEdge : IEdge <TVertex>
{
// let's verify the result
foreach (var v in algo.VisitedGraph.Vertices)
{
TEdge predecessor;
if (!predecessors.VertexPredecessors.TryGetValue(v, out predecessor))
{
continue;
}
if (predecessor.Source.Equals(v))
{
continue;
}
double vd, vp;
bool found;
Assert.Equal(found = algo.TryGetDistance(v, out vd), algo.TryGetDistance(predecessor.Source, out vp));
//if (found)
// Assert.Equal(vd, vp + 1, 8);
}
}
