public E AddEdge(V sourceVertex, V targetVertex)
{
AssertVertexExist(sourceVertex);
AssertVertexExist(targetVertex);
// TODO::review, since ContainsEdge calles GetEdge which calls ContainsVertex,
// and we have called AssertVertexExist already
if (ContainsEdge(sourceVertex, targetVertex))
{
return(default(E));
}
if (sourceVertex.Equals(targetVertex))
{
throw new ArgumentException(ErrorMessages.LoopsNotAllowed);
}
var edge = _edgeFactory.CreateEdge(sourceVertex, targetVertex);
_edges.Add(edge);
if (_vertexEdgeMap[sourceVertex] == null)
{
_vertexEdgeMap[sourceVertex] = new HashSet <E>();
}
_vertexEdgeMap[sourceVertex].Add(edge);
if (_vertexEdgeMap[targetVertex] == null)
{
_vertexEdgeMap[targetVertex] = new HashSet <E>();
}
_vertexEdgeMap[targetVertex].Add(edge);
return(edge);
}
public void MergeVertex(TVertex v, IEdgeFactory <TVertex, TEdge> edgeFactory)
{
GraphContracts.AssumeInVertexSet(this, v, "v");
GraphContracts.AssumeNotNull(edgeFactory, "edgeFactory");
// storing edges in local array
EdgeList inedges = this.vertexInEdges[v];
EdgeList outedges = this.vertexOutEdges[v];
// remove vertex
this.RemoveVertex(v);
// add edges from each source to each target
foreach (TEdge source in inedges)
{
//is it a self edge
if (source.Source.Equals(v))
{
continue;
}
foreach (TEdge target in outedges)
{
if (v.Equals(target.Target))
{
continue;
}
// we add an new edge
this.AddEdge(edgeFactory.CreateEdge(source.Source, target.Target));
}
}
}
public static void Create <TVertex, TEdge>(
IMutableVertexAndEdgeListGraph <TVertex, TEdge> g,
IVertexFactory <TVertex> vertexFactory,
IEdgeFactory <TVertex, TEdge> edgeFactory,
Random rnd,
int vertexCount,
int edgeCount,
bool selfEdges
) where TEdge : IEdge <TVertex>
{
if (g == null)
{
throw new ArgumentNullException("g");
}
if (vertexFactory == null)
{
throw new ArgumentNullException("vertexFactory");
}
if (edgeFactory == null)
{
throw new ArgumentNullException("edgeFactory");
}
if (rnd == null)
{
throw new ArgumentNullException("random generator");
}
for (int i = 0; i < vertexCount; ++i)
{
g.AddVertex(vertexFactory.CreateVertex());
}
TVertex a;
TVertex b;
int j = 0;
while (j < edgeCount)
{
a = GetVertex(g, rnd);
do
{
b = GetVertex(g, rnd);
}while (selfEdges == false && a.Equals(b));
if (g.AddEdge(edgeFactory.CreateEdge(a, b)))
{
++j;
}
}
}
public void CreateEdgeFactory()
{
IEdgeFactory <Foo, Edge <Foo> > factory = FactoryCompiler.GetEdgeFactory <Foo, Edge <Foo> >();
Assert.IsNotNull(factory);
Foo source = new Foo();
Foo target = new Foo();
Edge <Foo> edge = factory.CreateEdge(source, target);
Assert.IsNotNull(edge);
Assert.IsNotNull(edge.Source);
Assert.IsNotNull(edge.Target);
}
/// <summary>
/// Adds temporary edges to the graph to make all vertex even.
/// </summary>
/// <param name="g"></param>
/// <returns></returns>
public List <TEdge> AddTemporaryEdges(IEdgeFactory <TVertex, TEdge> edgeFactory)
{
// first gather odd edges.
List <TVertex> oddVertices = AlgoUtility.OddVertices(this.VisitedGraph);
// check that there are an even number of them
if (oddVertices.Count % 2 != 0)
{
throw new Exception("number of odd vertices in not even!");
}
// add temporary edges to create even edges:
this.temporaryEdges = new List <TEdge>();
bool found, foundbe, foundadjacent;
while (oddVertices.Count > 0)
{
TVertex u = oddVertices[0];
// find adjacent odd vertex.
found = false;
foundadjacent = false;
foreach (var e in this.VisitedGraph.OutEdges(u))
{
TVertex v = e.Target;
if (!v.Equals(u) && oddVertices.Contains(v))
{
foundadjacent = true;
// check that v does not have an out-edge towards u
foundbe = false;
foreach (var be in this.VisitedGraph.OutEdges(v))
{
if (be.Target.Equals(u))
{
foundbe = true;
break;
}
}
if (foundbe)
{
continue;
}
// add temporary edge
TEdge tempEdge = edgeFactory.CreateEdge(v, u);
if (!this.VisitedGraph.AddEdge(tempEdge))
{
throw new InvalidOperationException();
}
// add to collection
temporaryEdges.Add(tempEdge);
// remove u,v from oddVertices
oddVertices.Remove(u);
oddVertices.Remove(v);
// set u to null
found = true;
break;
}
}
if (!foundadjacent)
{
// pick another vertex
if (oddVertices.Count < 2)
{
throw new Exception("Eulerian trail failure");
}
TVertex v = oddVertices[1];
TEdge tempEdge = edgeFactory.CreateEdge(u, v);
if (!this.VisitedGraph.AddEdge(tempEdge))
{
throw new InvalidOperationException();
}
// add to collection
temporaryEdges.Add(tempEdge);
// remove u,v from oddVertices
oddVertices.Remove(u);
oddVertices.Remove(v);
// set u to null
found = true;
}
if (!found)
{
oddVertices.Remove(u);
oddVertices.Add(u);
}
}
return(this.temporaryEdges);
}
