public FlowEdge AddFlowEdge(Vertex from, Vertex to)
{
checkNullGraph(currentGraph);
FlowEdge fe = new FlowEdge(from, to, 0, 1f);
currentGraph.AddEdge(fe);
return fe;
}
public FlowEdge AddFlowEdge(Vertex from, Vertex to)
{
checkNullGraph(currentGraph);
FlowEdge fe = new FlowEdge(from, to, 0, 1f);
currentGraph.AddEdge(fe);
return(fe);
}
public void UpdateEdgeFlow(FlowEdge fe)
{
FlowEdge edge = FindEdge(fe);
if (edge != null)
{
edge.CurrentFlow = edge.CurrentFlow + fe.CurrentFlow;
}
}
public void UpdateEdgeFlow(FlowEdge fe)
{
FlowEdge edge = FindEdge(fe);
if (edge != null)
{
edge.CurrentFlow = edge.CurrentFlow + fe.CurrentFlow;
}
}
public FlowEdge FindEdge(FlowEdge fe)
{
foreach (FlowEdge flowEdge in edges)
{
if (flowEdge.Equals(fe))
{
return(flowEdge);
}
}
return(null);
}
public FlowEdge FindEdge(FlowEdge fe)
{
foreach (FlowEdge flowEdge in edges)
{
if (flowEdge.Equals(fe))
{
return flowEdge;
}
}
return null;
}
private void copyLinkedGraph(FlowNetwork to)
{
to.Clear();
for (int i = 0; i < this.GetVertices().Count; i++)
{
vertices[i].Tag = i;
Vertex v = new Vertex();
v.Tag = i;
to.AddVertex(v);
}
for (int i = 0; i < this.GetEdges().Count; i++)
{
Edge currentEdge = this.GetEdges()[i];
Vertex v1 = new Vertex();
v1.Label = currentEdge.GetFromVertex().Label;
int cd = (int)currentEdge.GetFromVertex().Tag;
if ((int)to.GetVertices()[cd].Tag == cd)
{
v1 = to.GetVertices()[cd];
}
Vertex v2 = new Vertex();
v2.Label = currentEdge.GetToVertex().Label;
int cd2 = (int)currentEdge.GetToVertex().Tag;
if ((int)to.GetVertices()[cd2].Tag == cd2)
{
v2 = to.GetVertices()[cd2];
}
FlowEdge fe = currentEdge as FlowEdge;
Edge e = new FlowEdge(v1, v2, fe.CurrentFlow, fe.Capacity);
to.AddEdge(e);
}
FlowNetwork fn = this as FlowNetwork;
if (fn != null)
{
to.SetSource(fn.GetSource());
to.SetSink(fn.GetSink());
}
}
private void copyLinkedGraph(FlowNetwork to)
{
to.Clear();
for (int i = 0; i < this.GetVertices().Count; i++)
{
vertices[i].Tag = i;
Vertex v = new Vertex();
v.Tag = i;
to.AddVertex(v);
}
for (int i = 0; i < this.GetEdges().Count; i++)
{
Edge currentEdge = this.GetEdges()[i];
Vertex v1 = new Vertex();
v1.Label = currentEdge.GetFromVertex().Label;
int cd = (int)currentEdge.GetFromVertex().Tag;
if ((int)to.GetVertices()[cd].Tag == cd)
{
v1 = to.GetVertices()[cd];
}
Vertex v2 = new Vertex();
v2.Label = currentEdge.GetToVertex().Label;
int cd2 = (int)currentEdge.GetToVertex().Tag;
if ((int)to.GetVertices()[cd2].Tag == cd2)
{
v2 = to.GetVertices()[cd2];
}
FlowEdge fe = currentEdge as FlowEdge;
Edge e = new FlowEdge(v1, v2, fe.CurrentFlow, fe.Capacity);
to.AddEdge(e);
}
FlowNetwork fn = this as FlowNetwork;
if (fn != null)
{
to.SetSource(fn.GetSource());
to.SetSink(fn.GetSink());
}
}
public static float MaximumFlow(FlowNetwork fn, int source, int sink)
{
float maxFlow = 0f;
int sourceIndex = source;
int sinkIndex = sink;
foreach (FlowEdge e in fn.GetEdges())
{
e.CurrentFlow = 0f;
}
Graph g = CreateResidualNetwork(fn);
List <Edge> augmentingPath = BreadthFirstSearch(g, sourceIndex, sinkIndex);
while (augmentingPath != null)
{
float minFlow = float.MaxValue;
//find min flow
foreach (Edge e in augmentingPath)
{
if (e.Weight < minFlow)
{
minFlow = e.Weight;
}
}
maxFlow += minFlow;
foreach (Edge e in augmentingPath)
{
//Update residual graph
Edge currentForwardResid = g.FindEdge(e);
Edge currentBackwardResid = g.FindEdge(new Edge(e.GetToVertex(), e.GetFromVertex()));
float newForwardWeight = currentForwardResid.Weight - minFlow;
if (newForwardWeight <= 0f)
{
g.RemoveEdge(currentForwardResid);
}
else
{
currentForwardResid.Weight = newForwardWeight;
}
if (currentBackwardResid != null)
{
float newBackwardWeight = currentBackwardResid.Weight + minFlow;
currentBackwardResid.Weight = newBackwardWeight;
}
else
{
currentBackwardResid = new Edge(e.GetToVertex(), e.GetFromVertex(), minFlow);
g.AddEdge(currentBackwardResid);
}
//Update flow network
FlowEdge fe = fn.FindEdge(new FlowEdge(e.GetFromVertex(), e.GetToVertex(), 0, 0));
fe.CurrentFlow = fe.CurrentFlow + minFlow;
}
augmentingPath = BreadthFirstSearch(g, sourceIndex, sinkIndex);
//augmentingPath = null;
}
return(maxFlow);
}
