private void VerifyCounts(IMutableVertexAndEdgeListGraph <string, Edge <string> > g)
{
int i = 0;
foreach (string v in g.Vertices)
{
i++;
}
Assert.Equal(g.VertexCount, i);
i = 0;
foreach (string v in g.Vertices)
{
foreach (Edge <string> e in g.OutEdges(v))
{
i++;
}
}
Assert.Equal(g.EdgeCount, i);
i = 0;
foreach (Edge <string> e in g.Edges)
{
i++;
}
Assert.Equal(g.EdgeCount, i);
}
/// <summary>
/// Computes the maximum flow between <see cref="MaximumFlowAlgorithm{TVertex,TEdge}.Source"/>
/// and <see cref="MaximumFlowAlgorithm{TVertex,TEdge}.Sink"/>.
/// </summary>
protected override void InternalCompute()
{
ThrowIfCancellationRequested();
IMutableVertexAndEdgeListGraph <TVertex, TEdge> graph = VisitedGraph;
foreach (TVertex vertex in graph.Vertices)
{
foreach (TEdge edge in graph.OutEdges(vertex))
{
double capacity = Capacities(edge);
if (capacity < 0)
{
throw new NegativeCapacityException();
}
ResidualCapacities[edge] = capacity;
}
}
VerticesColors[Sink] = GraphColor.Gray;
while (VerticesColors[Sink] != GraphColor.White)
{
var verticesPredecessors = new VertexPredecessorRecorderObserver <TVertex, TEdge>(Predecessors);
var queue = new Collections.Queue <TVertex>();
var bfs = new BreadthFirstSearchAlgorithm <TVertex, TEdge>(
ResidualGraph,
queue,
VerticesColors);
using (verticesPredecessors.Attach(bfs))
bfs.Compute(Source);
if (VerticesColors[Sink] != GraphColor.White)
{
Augment(Source, Sink);
}
}
MaxFlow = 0;
foreach (TEdge edge in graph.OutEdges(Source))
{
MaxFlow += (Capacities(edge) - ResidualCapacities[edge]);
}
}
/// <summary>
/// Adds temporary edges to the graph to make all vertex even.
/// </summary>
/// <param name="g"></param>
/// <returns></returns>
public EdgeCollection AddTemporaryEdges(IMutableVertexAndEdgeListGraph g)
{
if (g==null)
throw new ArgumentNullException("g");
// first gather odd edges.
VertexCollection oddVertices = AlgoUtility.OddVertices(g);
// 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:
EdgeCollection ec = new EdgeCollection();
bool found,foundbe,foundadjacent;
while (oddVertices.Count > 0)
{
IVertex u = oddVertices[0];
// find adjacent odd vertex.
found = false;
foundadjacent = false;
foreach(IEdge e in g.OutEdges(u))
{
IVertex v = e.Target;
if (v!=u && oddVertices.Contains(v))
{
foundadjacent=true;
// check that v does not have an out-edge towards u
foundbe = false;
foreach(IEdge be in g.OutEdges(v))
{
if (be.Target==u)
{
foundbe = true;
break;
}
}
if (foundbe)
continue;
// add temporary edge
IEdge tempEdge = g.AddEdge(v,u);
// add to collection
ec.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");
IVertex v = oddVertices[1];
IEdge tempEdge = g.AddEdge(u,v);
// add to collection
ec.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);
}
}
temporaryEdges = ec;
return ec;
}
private void VerifyCounts(IMutableVertexAndEdgeListGraph<string, Edge<string>> g)
{
int i = 0;
foreach (string v in g.Vertices)
i++;
Assert.AreEqual(g.VertexCount, i);
i = 0;
foreach (string v in g.Vertices)
foreach (Edge<string> e in g.OutEdges(v))
i++;
Assert.AreEqual(g.EdgeCount, i);
i = 0;
foreach (Edge<string> e in g.Edges)
i++;
Assert.AreEqual(g.EdgeCount, i);
}
public EdgeCollection AddTemporaryEdges(IMutableVertexAndEdgeListGraph g)
{
if (g == null)
{
throw new ArgumentNullException("g");
}
VertexCollection vertexs = QuickGraph.Algorithms.AlgoUtility.OddVertices(g);
if ((vertexs.Count % 2) != 0)
{
throw new Exception("number of odd vertices in not even!");
}
EdgeCollection edges = new EdgeCollection();
while (vertexs.Count > 0)
{
IVertex vertex = vertexs.get_Item(0);
bool flag = false;
bool flag3 = false;
IEdgeEnumerator enumerator = g.OutEdges(vertex).GetEnumerator();
while (enumerator.MoveNext())
{
IVertex vertex2 = enumerator.get_Current().get_Target();
if ((vertex2 != vertex) && vertexs.Contains(vertex2))
{
flag3 = true;
bool flag2 = false;
IEdgeEnumerator enumerator2 = g.OutEdges(vertex2).GetEnumerator();
while (enumerator2.MoveNext())
{
if (enumerator2.get_Current().get_Target() == vertex)
{
flag2 = true;
break;
}
}
if (!flag2)
{
IEdge edge3 = g.AddEdge(vertex2, vertex);
edges.Add(edge3);
vertexs.Remove(vertex);
vertexs.Remove(vertex2);
flag = true;
break;
}
}
}
if (!flag3)
{
if (vertexs.Count < 2)
{
throw new Exception("Eulerian trail failure");
}
IVertex vertex3 = vertexs.get_Item(1);
IEdge edge4 = g.AddEdge(vertex, vertex3);
edges.Add(edge4);
vertexs.Remove(vertex);
vertexs.Remove(vertex3);
flag = true;
}
if (!flag)
{
vertexs.Remove(vertex);
vertexs.Add(vertex);
}
}
this.temporaryEdges = edges;
return edges;
}
/// <summary>
/// Adds temporary edges to the graph to make all vertex even.
/// </summary>
/// <param name="g"></param>
/// <returns></returns>
public EdgeCollection AddTemporaryEdges(IMutableVertexAndEdgeListGraph g)
{
if (g == null)
{
throw new ArgumentNullException("g");
}
// first gather odd edges.
VertexCollection oddVertices = AlgoUtility.OddVertices(g);
// 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:
EdgeCollection ec = new EdgeCollection();
bool found, foundbe, foundadjacent;
while (oddVertices.Count > 0)
{
IVertex u = oddVertices[0];
// find adjacent odd vertex.
found = false;
foundadjacent = false;
foreach (IEdge e in g.OutEdges(u))
{
IVertex v = e.Target;
if (v != u && oddVertices.Contains(v))
{
foundadjacent = true;
// check that v does not have an out-edge towards u
foundbe = false;
foreach (IEdge be in g.OutEdges(v))
{
if (be.Target == u)
{
foundbe = true;
break;
}
}
if (foundbe)
{
continue;
}
// add temporary edge
IEdge tempEdge = g.AddEdge(v, u);
// add to collection
ec.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");
}
IVertex v = oddVertices[1];
IEdge tempEdge = g.AddEdge(u, v);
// add to collection
ec.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);
}
}
temporaryEdges = ec;
return(ec);
}