public double Compute(Vertex src, Vertex sink)
{
m_ResidualEdgeCapacities = new EdgeDoubleDictionary();
// initializing
foreach(Vertex u in VisitedGraph.Vertices)
foreach(Edge e in u.OutEdges)
ResidualCapacities[e] = Capacities[e];
Colors[sink] = GraphColor.Gray;
while (Colors[sink] != GraphColor.White)
{
VertexBuffer Q = new VertexBuffer();
ResidualEdgePredicate ep = new ResidualEdgePredicate(ResidualCapacities);
BreadthFirstSearchAlgorithm bfs = new BreadthFirstSearchAlgorithm(resg,Q,Colors);
PredecessorVisitor pred = new PredecessorVisitor(Predecessors);
pred.RegisterHandlers(bfs);
bfs.Compute(src);
if (Colors[sink] != GraphColor.White)
Augment(src, sink, pred.Predecessors);
} // while
double flow = 0;
foreach(Edge e in src.OutEdges)
flow += (EdgeCapacities[e] - ResidualEdgeCapacities[e]);
return flow;
}
public void GraphWithSelfEdges(
[UsingLinear(2, 9)] int i,
[UsingLinear(0, 10)] int j
)
{
if (i == 0 && j == 0)
{
return;
}
Random rnd = new Random();
g = new AdjacencyGraph <int, Edge <int> >(true);
RandomGraphFactory.Create <int, Edge <int> >(g,
new IntVertexFactory(),
FactoryCompiler.GetEdgeFactory <int, Edge <int> >(),
rnd, i, j, true);
algo = new BreadthFirstSearchAlgorithm <int, Edge <int> >(g);
try
{
algo.InitializeVertex += new VertexEventHandler <int>(this.InitializeVertex);
algo.DiscoverVertex += new VertexEventHandler <int>(this.DiscoverVertex);
algo.ExamineEdge += new EdgeEventHandler <int, Edge <int> >(this.ExamineEdge);
algo.ExamineVertex += new VertexEventHandler <int>(this.ExamineVertex);
algo.TreeEdge += new EdgeEventHandler <int, Edge <int> >(this.TreeEdge);
algo.NonTreeEdge += new EdgeEventHandler <int, Edge <int> >(this.NonTreeEdge);
algo.GrayTarget += new EdgeEventHandler <int, Edge <int> >(this.GrayTarget);
algo.BlackTarget += new EdgeEventHandler <int, Edge <int> >(this.BlackTarget);
algo.FinishVertex += new VertexEventHandler <int>(this.FinishVertex);
parents.Clear();
distances.Clear();
currentDistance = 0;
sourceVertex = RandomGraphFactory.GetVertex(g, rnd);
foreach (int v in g.Vertices)
{
distances[v] = int.MaxValue;
parents[v] = v;
}
distances[sourceVertex] = 0;
algo.Compute(sourceVertex);
CheckBfs();
}
finally
{
algo.InitializeVertex -= new VertexEventHandler <int>(this.InitializeVertex);
algo.DiscoverVertex -= new VertexEventHandler <int>(this.DiscoverVertex);
algo.ExamineEdge -= new EdgeEventHandler <int, Edge <int> >(this.ExamineEdge);
algo.ExamineVertex -= new VertexEventHandler <int>(this.ExamineVertex);
algo.TreeEdge -= new EdgeEventHandler <int, Edge <int> >(this.TreeEdge);
algo.NonTreeEdge -= new EdgeEventHandler <int, Edge <int> >(this.NonTreeEdge);
algo.GrayTarget -= new EdgeEventHandler <int, Edge <int> >(this.GrayTarget);
algo.BlackTarget -= new EdgeEventHandler <int, Edge <int> >(this.BlackTarget);
algo.FinishVertex -= new VertexEventHandler <int>(this.FinishVertex);
}
}
public void Init()
{
this.parents = new Dictionary <int, int>();
this.distances = new Dictionary <int, int>();
this.currentDistance = 0;
this.currentVertex = 0;
this.algo = null;
this.g = null;
}
public override double Compute(IVertex src, IVertex sink)
{
if (src == null)
{
throw new ArgumentNullException("src");
}
if (sink == null)
{
throw new ArgumentNullException("sink");
}
IVertexEnumerator enumerator = base.VisitedGraph.get_Vertices().GetEnumerator();
while (enumerator.MoveNext())
{
IVertex vertex = enumerator.get_Current();
IEdgeEnumerator enumerator2 = base.VisitedGraph.OutEdges(vertex).GetEnumerator();
while (enumerator2.MoveNext())
{
IEdge edge = enumerator2.get_Current();
base.ResidualCapacities.set_Item(edge, base.Capacities.get_Item(edge));
}
}
base.Colors.set_Item(sink, 2);
while (base.Colors.get_Item(sink) != null)
{
PredecessorRecorderVisitor vis = new PredecessorRecorderVisitor(base.Predecessors);
VertexBuffer q = new VertexBuffer();
BreadthFirstSearchAlgorithm algorithm = new BreadthFirstSearchAlgorithm(this.ResidualGraph, q, base.Colors);
algorithm.RegisterPredecessorRecorderHandlers(vis);
algorithm.Compute(src);
if (base.Colors.get_Item(sink) != null)
{
this.Augment(src, sink);
}
}
double num = 0.0;
IEdgeEnumerator enumerator3 = base.VisitedGraph.OutEdges(src).GetEnumerator();
while (enumerator3.MoveNext())
{
IEdge edge2 = enumerator3.get_Current();
num += base.Capacities.get_Item(edge2) - base.ResidualCapacities.get_Item(edge2);
}
return num;
}
internal void ComputeNoInit(IVertex s)
{
m_VertexQueue = new PriorithizedVertexBuffer(m_Distances);
BreadthFirstSearchAlgorithm bfs = new BreadthFirstSearchAlgorithm(
VisitedGraph,
m_VertexQueue,
Colors
);
bfs.InitializeVertex += this.InitializeVertex;
bfs.DiscoverVertex += this.DiscoverVertex;
bfs.ExamineEdge += this.ExamineEdge;
bfs.ExamineVertex += this.ExamineVertex;
bfs.FinishVertex += this.FinishVertex;
bfs.TreeEdge += new EdgeHandler(this.TreeEdge);
bfs.GrayTarget += new EdgeHandler(this.GrayTarget);
bfs.Visit(s);
}
/// <summary>
/// Computes a set of eulerian trail, starting at <paramref name="s"/>
/// that spans the entire graph.
/// </summary>
/// <remarks>
/// <para>
/// This method computes a set of eulerian trail starting at <paramref name="s"/>
/// that spans the entire graph.The algorithm outline is as follows:
/// </para>
/// <para>
/// The algorithms iterates throught the Eulerian circuit of the augmented
/// graph (the augmented graph is the graph with additional edges to make
/// the number of odd vertices even).
/// </para>
/// <para>
/// If the current edge is not temporary, it is added to the current trail.
/// </para>
/// <para>
/// If the current edge is temporary, the current trail is finished and
/// added to the trail collection. The shortest path between the
/// start vertex <paramref name="s"/> and the target vertex of the
/// temporary edge is then used to start the new trail. This shortest
/// path is computed using the <see cref="BreadthFirstSearchAlgorithm"/>.
/// </para>
/// </remarks>
/// <param name="s">start vertex</param>
/// <returns>eulerian trail set, all starting at s</returns>
/// <exception cref="ArgumentNullException">s is a null reference.</exception>
/// <exception cref="Exception">Eulerian trail not computed yet.</exception>
public EdgeCollectionCollection Trails(IVertex s)
{
if (s==null)
throw new ArgumentNullException("s");
if (this.Circuit.Count==0)
throw new Exception("Circuit is empty");
// find the first edge in the circuit.
int i=0;
for(i=0;i<this.Circuit.Count;++i)
{
IEdge e = this.Circuit[i];
if (TemporaryEdges.Contains(e))
continue;
if (e.Source == s)
break;
}
if (i==this.Circuit.Count)
throw new Exception("Did not find vertex in eulerian trail?");
// create collections
EdgeCollectionCollection trails = new EdgeCollectionCollection();
EdgeCollection trail = new EdgeCollection();
BreadthFirstSearchAlgorithm bfs =
new BreadthFirstSearchAlgorithm(VisitedGraph);
PredecessorRecorderVisitor vis = new PredecessorRecorderVisitor();
bfs.RegisterPredecessorRecorderHandlers(vis);
bfs.Compute(s);
// go throught the edges and build the predecessor table.
int start = i;
for (;i<this.Circuit.Count;++i)
{
IEdge e = this.Circuit[i];
if (TemporaryEdges.Contains(e))
{
// store previous trail and start new one.
if(trail.Count != 0)
trails.Add(trail);
// start new trail
// take the shortest path from the start vertex to
// the target vertex
trail = vis.Path(e.Target);
}
else
trail.Add(e);
}
// starting again on the circuit
for (i=0;i<start;++i)
{
IEdge e = this.Circuit[i];
if (TemporaryEdges.Contains(e))
{
// store previous trail and start new one.
if(trail.Count != 0)
trails.Add(trail);
// start new trail
// take the shortest path from the start vertex to
// the target vertex
trail = vis.Path(e.Target);
}
else
trail.Add(e);
}
// adding the last element
if (trail.Count!=0)
trails.Add(trail);
return trails;
}
public void BreadthFirstSearch(IVertexAndEdgeListGraph<string, Edge<string>> g)
{
var bfs = new BreadthFirstSearchAlgorithm<string, Edge<string>>(g);
bfs.Compute();
}
private void RemoveIrrelevantBranches(AdjacencyGraph<IBuilder, EquatableEdge<IBuilder>> graph, IBuilder rootBuilder)
{
var bfs = new BreadthFirstSearchAlgorithm<IBuilder, EquatableEdge<IBuilder>>(graph);
var toKeep = new HashSet<EquatableEdge<IBuilder>>();
var buildersToKeep = new HashSet<IBuilder>();
bfs.TreeEdge += e => toKeep.Add(e);
bfs.NonTreeEdge += e => toKeep.Add(e);
bfs.DiscoverVertex += b => buildersToKeep.Add(b);
bfs.Compute(rootBuilder);
graph.RemoveEdgeIf(edge => !toKeep.Contains(edge));
graph.RemoveVertexIf(vertex => !buildersToKeep.Contains(vertex));
}
/// <summary>
/// Computes the maximum flow between <paramref name="src"/> and
/// <paramref name="sink"/>
/// </summary>
/// <param name="src"></param>
/// <param name="sink"></param>
/// <returns></returns>
public override double Compute(IVertex src, IVertex sink)
{
if (src==null)
throw new ArgumentNullException("src");
if (sink==null)
throw new ArgumentNullException("sink");
foreach(IVertex u in VisitedGraph.Vertices)
{
foreach(IEdge e in VisitedGraph.OutEdges(u))
{
ResidualCapacities[e] = Capacities[e];
}
}
Colors[sink] = GraphColor.Gray;
while (Colors[sink] != GraphColor.White)
{
PredecessorRecorderVisitor vis = new PredecessorRecorderVisitor(
Predecessors
);
VertexBuffer Q = new VertexBuffer();
BreadthFirstSearchAlgorithm bfs = new BreadthFirstSearchAlgorithm(
ResidualGraph,
Q,
Colors
);
bfs.RegisterPredecessorRecorderHandlers(vis);
bfs.Compute(src);
if (Colors[sink] != GraphColor.White)
Augment(src, sink);
} // while
double flow=0;
foreach(IEdge e in VisitedGraph.OutEdges(src))
flow += (Capacities[e] - ResidualCapacities[e]);
return flow;
}
private void GlobalDistanceUpdate()
{
IVertexEnumerator enumerator = this.VisitedGraph.get_Vertices().GetEnumerator();
while (enumerator.MoveNext())
{
IVertex vertex = enumerator.get_Current();
base.Colors.set_Item(vertex, 0);
this.Distances.set_Item(vertex, this.n);
}
this.Distances.set_Item(this.sink, 0);
for (int i = 0; i <= this.maxDistance; i++)
{
this.layers[i].ActiveVertices.Clear();
this.layers[i].InactiveVertices.Clear();
}
this.maxDistance = this.maxActive = 0;
this.minActive = this.n;
BreadthFirstSearchAlgorithm algorithm = new BreadthFirstSearchAlgorithm(this.ResidualGraph, new VertexBuffer(), base.Colors);
DistanceRecorderVisitor visitor = new DistanceRecorderVisitor(this.Distances);
algorithm.TreeEdge += new EdgeEventHandler(visitor, (IntPtr) this.TreeEdge);
algorithm.DiscoverVertex += new VertexEventHandler(this, (IntPtr) this.GlobalDistanceUpdateHelper);
algorithm.Compute(this.sink);
}
private void RemoveIrrelevantBranches(AdjacencyGraph<IBuilder, EquatableEdge<IBuilder>> graph, IBuilder rootBuilder)
{
var bfs = new BreadthFirstSearchAlgorithm<IBuilder, EquatableEdge<IBuilder>>(graph);
bfs.Compute(rootBuilder);
var toKeep = new HashSet<IBuilder>(bfs.VisitedGraph.Vertices);
graph.RemoveVertexIf(v => !toKeep.Contains(v));
}
protected void CheckBfs(IVertexListGraph g, BreadthFirstSearchAlgorithm bfs)
{
// All white vertices should be unreachable from the source.
foreach(IVertex v in g.Vertices)
{
if (bfs.Colors[v]==GraphColor.White)
{
//!IsReachable(start,u,g);
}
}
// The shortest path to a child should be one longer than
// shortest path to the parent.
foreach(IVertex v in g.Vertices)
{
if (Parents[v] != v) // *ui not the root of the bfs tree
Assert.AreEqual(Distances[v], Distances[Parents[v]] + 1);
}
}
public void GraphWithSelfEdges()
{
Random rnd = new Random();
for (int i = 0; i <10; ++i)
for (int j = 0; j < i*i; ++j)
{
AdjacencyGraph g = new AdjacencyGraph(
new QuickGraph.Providers.VertexProvider(),
new QuickGraph.Providers.EdgeProvider(),
true);
RandomGraph.Graph(g,i,j,rnd,true);
BreadthFirstSearchAlgorithm bfs = new BreadthFirstSearchAlgorithm(g);
bfs.InitializeVertex += new VertexEventHandler( this.InitializeVertex);
bfs.DiscoverVertex += new VertexEventHandler(this.DiscoverVertex);
bfs.ExamineEdge += new EdgeEventHandler(this.ExamineEdge);
bfs.ExamineVertex += new VertexEventHandler(this.ExamineVertex);
bfs.TreeEdge += new EdgeEventHandler(this.TreeEdge);
bfs.NonTreeEdge += new EdgeEventHandler(this.NonTreeEdge);
bfs.GrayTarget += new EdgeEventHandler(this.GrayTarget);
bfs.BlackTarget += new EdgeEventHandler(this.BlackTarget);
bfs.FinishVertex += new VertexEventHandler(this.FinishVertex);
Parents.Clear();
Distances.Clear();
m_CurrentDistance = 0;
m_SourceVertex = RandomGraph.Vertex(g, rnd);
foreach(IVertex v in g.Vertices)
{
Distances[v]=int.MaxValue;
Parents[v]=v;
}
Distances[SourceVertex]=0;
bfs.Compute(SourceVertex);
CheckBfs(g,bfs);
}
}
//=======================================================================
// This is a breadth-first search over the residual graph
// (well, actually the reverse of the residual graph).
// Would be cool to have a graph view adaptor for hiding certain
// edges, like the saturated (non-residual) edges in this case.
// Goldberg's implementation abused "distance" for the coloring.
private void GlobalDistanceUpdate()
{
foreach (IVertex u in VisitedGraph.Vertices)
{
Colors[u] = GraphColor.White;
Distances[u] = n;
}
Distances[sink] = 0;
for (int l = 0; l <= maxDistance; ++l)
{
layers[l].ActiveVertices.Clear();
layers[l].InactiveVertices.Clear();
}
maxDistance = maxActive = 0;
minActive = n;
BreadthFirstSearchAlgorithm bfs = new BreadthFirstSearchAlgorithm(
ResidualGraph,
new VertexBuffer(),
Colors
);
DistanceRecorderVisitor vis = new DistanceRecorderVisitor(Distances);
bfs.TreeEdge += new EdgeEventHandler(vis.TreeEdge);
bfs.DiscoverVertex += new VertexEventHandler(GlobalDistanceUpdateHelper);
bfs.Compute(sink);
}
static void Main(string[] args)
{
try
{
/*
VertexStringDictionary verticesNames = new VertexStringDictionary();
EdgeStringDictionary edgesNames = new EdgeStringDictionary();
EdgeDoubleDictionary edgesWeights = new EdgeDoubleDictionary();
IncidenceGraph g = new IncidenceGraph(true);
// adding vertex
Vertex u = g.AddVertex();
verticesNames[u]="u";
Vertex v = g.AddVertex();
verticesNames[v]="v";
Vertex w = g.AddVertex();
verticesNames[w]="w";
Vertex x = g.AddVertex();
verticesNames[x]="x";
Vertex y = g.AddVertex();
verticesNames[y]="y";
Vertex z = g.AddVertex();
verticesNames[z]="z";
// adding edges
Edge uv = g.AddEdge(u,v);
edgesNames[uv]="uv";
edgesWeights[uv]=1;
Edge ux = g.AddEdge(u,x);
edgesNames[ux]="ux";
edgesWeights[ux]=0.8;
Edge wu = g.AddEdge(w,u);
g.AddEdge(w,u);
edgesNames[wu]="wu";
edgesWeights[wu]=0.2;
Edge xv = g.AddEdge(x,v);
edgesNames[xv]="xv";
edgesWeights[xv]=1.1;
Edge vy = g.AddEdge(v,y);
edgesNames[vy]="vy";
edgesWeights[vy]=2.0;
Edge wy = g.AddEdge(w,y);
edgesNames[wy]="wy";
edgesWeights[wy]=1.5;
Edge yw = g.AddEdge(y,w);
edgesNames[yw]="yw";
edgesWeights[yw]=0.2;
Edge wz = g.AddEdge(w,z);
edgesNames[wz]="wz";
edgesWeights[wz]=0.1;
RandomGraph.Graph(g, 20,50,new Random(),true);
/*
// do a dfs serach
Console.WriteLine("---- DepthFirstSearch");
DepthFirstSearchAlgorithm dfs = new DepthFirstSearchAlgorithm(g);
//TestDepthFirstSearchVisitor dfsVis =
// new TestDepthFirstSearchVisitor(dfs,verticesNames);
AlgorithmTracerVisitor dfstracer = new
AlgorithmTracerVisitor(g,"dfs",".",GraphvizImageType.Png);
dfstracer.VertexLabels = verticesNames;
dfstracer.RegisterVertexHandlers(dfs);
dfstracer.RegisterEdgeHandlers(dfs);
dfs.Compute();
*/
Vertex source = u;
source = RandomGraph.Vertex(g,new Random());
Console.WriteLine("source: {0}",source.GetHashCode());
Console.WriteLine("---- BreathFirstSearch");
BreadthFirstSearchAlgorithm bfs = new BreadthFirstSearchAlgorithm(g);
TestBreadthFirstSearchVisitor bfsVis
= new TestBreadthFirstSearchVisitor(bfs,verticesNames,source);
AlgorithmTracerVisitor bfstracer = new
AlgorithmTracerVisitor(g,"bfs",".",GraphvizImageType.Png);
// bfstracer.VertexLabels = verticesNames;
bfs.RegisterTreeEdgeBuilderHandlers(bfsTracer);
bfs.RegisterVertexColorizeHandlers(bfsTracer);
bfs.Compute(source);
/*
Console.WriteLine("---- Dijkstra");
DijkstraShortestPathAlgorithm dij = new DijkstraShortestPathAlgorithm(
g,
edgesWeights
);
TestDijkstraShortestPathVisitor dijVis = new TestDijkstraShortestPathVisitor(dij,verticesNames);
AlgorithmTracerVisitor dijtracer = new
AlgorithmTracerVisitor(g,"dij",".",GraphvizImageType.Png);
dijtracer.VertexLabels = verticesNames;
dijtracer.EdgeLabels = edgesWeights;
dijtracer.RegisterVertexHandlers(dij);
// dijtracer.RegisterEdgeHandlers(dij);
dij.Compute(g.Vertex(0));
Console.WriteLine("Distance from {0}", verticesNames[g.Vertex(0)]);
foreach(DictionaryEntry de in dij.Distances)
{
Console.WriteLine("\t-> {0}, {1}",
verticesNames[(Vertex)de.Key],
de.Value.ToString()
);
}
Console.WriteLine("---- Topological sort");
VertexCollection vs = new VertexCollection();
TopologicalSortAlgorithm tps= new TopologicalSortAlgorithm(g);
tps.Compute(vs);
foreach(Vertex ve in vs)
{
Console.WriteLine("v - {0}",verticesNames[ve]);
}
Console.WriteLine("--- graphviz output");
GraphvizWriterAlgorithm gw = new GraphvizWriterAlgorithm(
g,"dotgenerator",".",GraphvizImageType.Png);
TestGraphvizVertex gv = new TestGraphvizVertex(verticesNames);
gw.WriteVertex += new VertexHandler( gv.WriteVertex );
gw.WriteEdge+= new EdgeHandler( gv.WriteEdge );
gw.Write(GraphvizImageType.Png);
gw.Write(GraphvizImageType.Svg);
gw.Write(GraphvizImageType.Svgz);
gw.Write(GraphvizImageType.Gif);
gw.Write(GraphvizImageType.Jpeg);
*/
Console.WriteLine("Test finished");
String s2=Console.ReadLine();
}
catch(Exception ex)
{
Console.WriteLine(ex.ToString());
String s=Console.ReadLine();
}
}
public EdgeCollectionCollection Trails(IVertex s)
{
if (s == null)
{
throw new ArgumentNullException("s");
}
if (this.Circuit.Count == 0)
{
throw new Exception("Circuit is empty");
}
int num = 0;
num = 0;
while (num < this.Circuit.Count)
{
IEdge edge = this.Circuit.get_Item(num);
if (!this.TemporaryEdges.Contains(edge) && (edge.get_Source() == s))
{
break;
}
num++;
}
if (num == this.Circuit.Count)
{
throw new Exception("Did not find vertex in eulerian trail?");
}
EdgeCollectionCollection collections = new EdgeCollectionCollection();
EdgeCollection edges = new EdgeCollection();
BreadthFirstSearchAlgorithm algorithm = new BreadthFirstSearchAlgorithm(this.VisitedGraph);
PredecessorRecorderVisitor vis = new PredecessorRecorderVisitor();
algorithm.RegisterPredecessorRecorderHandlers(vis);
algorithm.Compute(s);
int num2 = num;
while (num < this.Circuit.Count)
{
IEdge edge2 = this.Circuit.get_Item(num);
if (this.TemporaryEdges.Contains(edge2))
{
if (edges.Count != 0)
{
collections.Add(edges);
}
edges = vis.Path(edge2.get_Target());
}
else
{
edges.Add(edge2);
}
num++;
}
for (num = 0; num < num2; num++)
{
IEdge edge3 = this.Circuit.get_Item(num);
if (this.TemporaryEdges.Contains(edge3))
{
if (edges.Count != 0)
{
collections.Add(edges);
}
edges = vis.Path(edge3.get_Target());
}
else
{
edges.Add(edge3);
}
}
if (edges.Count != 0)
{
collections.Add(edges);
}
return collections;
}
public void RunBfs <TVertex, TEdge>(IVertexAndEdgeListGraph <TVertex, TEdge> g, TVertex sourceVertex)
where TEdge : IEdge <TVertex>
{
var parents = new Dictionary <TVertex, TVertex>();
var distances = new Dictionary <TVertex, int>();
TVertex currentVertex = default(TVertex);
int currentDistance = 0;
var algo = new BreadthFirstSearchAlgorithm <TVertex, TEdge>(g);
algo.InitializeVertex += u =>
{
Assert.AreEqual(algo.VertexColors[u], GraphColor.White);
};
algo.DiscoverVertex += u =>
{
Assert.AreEqual(algo.VertexColors[u], GraphColor.Gray);
if (u.Equals(sourceVertex))
{
currentVertex = sourceVertex;
}
else
{
Assert.IsNotNull(currentVertex);
Assert.AreEqual(parents[u], currentVertex);
Assert.AreEqual(distances[u], currentDistance + 1);
Assert.AreEqual(distances[u], distances[parents[u]] + 1);
}
};
algo.ExamineEdge += args =>
{
Assert.AreEqual(args.Source, currentVertex);
};
algo.ExamineVertex += args =>
{
var u = args;
currentVertex = u;
// Ensure that the distances monotonically increase.
Assert.IsTrue(
distances[u] == currentDistance ||
distances[u] == currentDistance + 1
);
if (distances[u] == currentDistance + 1) // new level
{
++currentDistance;
}
};
algo.TreeEdge += args =>
{
var u = args.Source;
var v = args.Target;
Assert.AreEqual(algo.VertexColors[v], GraphColor.White);
Assert.AreEqual(distances[u], currentDistance);
parents[v] = u;
distances[v] = distances[u] + 1;
};
algo.NonTreeEdge += args =>
{
var u = args.Source;
var v = args.Target;
Assert.IsFalse(algo.VertexColors[v] == GraphColor.White);
if (algo.VisitedGraph.IsDirected)
{
// cross or back edge
Assert.IsTrue(distances[v] <= distances[u] + 1);
}
else
{
// cross edge (or going backwards on a tree edge)
Assert.IsTrue(
distances[v] == distances[u] ||
distances[v] == distances[u] + 1 ||
distances[v] == distances[u] - 1
);
}
};
algo.GrayTarget += args =>
{
Assert.AreEqual(algo.VertexColors[args.Target], GraphColor.Gray);
};
algo.BlackTarget += args =>
{
Assert.AreEqual(algo.VertexColors[args.Target], GraphColor.Black);
foreach (var e in algo.VisitedGraph.OutEdges(args.Target))
{
Assert.IsFalse(algo.VertexColors[e.Target] == GraphColor.White);
}
};
algo.FinishVertex += args =>
{
Assert.AreEqual(algo.VertexColors[args], GraphColor.Black);
};
parents.Clear();
distances.Clear();
currentDistance = 0;
foreach (var v in g.Vertices)
{
distances[v] = int.MaxValue;
parents[v] = v;
}
distances[sourceVertex] = 0;
algo.Compute(sourceVertex);
// All white vertices should be unreachable from the source.
foreach (var v in g.Vertices)
{
if (algo.VertexColors[v] == GraphColor.White)
{
//!IsReachable(start,u,g);
}
}
// The shortest path to a child should be one longer than
// shortest path to the parent.
foreach (var v in g.Vertices)
{
if (!parents[v].Equals(v)) // *ui not the root of the bfs tree
{
Assert.AreEqual(distances[v], distances[parents[v]] + 1);
}
}
}
private bool IsOptimal(MaximumFlowAlgorithm maxFlow)
{
// check if mincut is saturated...
FilteredVertexListGraph residualGraph = new FilteredVertexListGraph(
maxFlow.VisitedGraph,
new ReversedResidualEdgePredicate(maxFlow.ResidualCapacities, maxFlow.ReversedEdges)
);
BreadthFirstSearchAlgorithm bfs = new BreadthFirstSearchAlgorithm(residualGraph);
VertexIntDictionary distances = new VertexIntDictionary();
DistanceRecorderVisitor vis = new DistanceRecorderVisitor(distances);
bfs.RegisterDistanceRecorderHandlers(vis);
bfs.Compute(sink);
return distances[source] >= maxFlow.VisitedGraph.VerticesCount;
}
public void GraphWithSelfEdgesPUT1(int v, int e, bool self)
{
AdjacencyGraph g = null;
RandomGraph.Graph(g, v, e, new Random(), self);
BreadthFirstSearchAlgorithm bfs = new BreadthFirstSearchAlgorithm(g);
}
public void ComputeNoInit(IVertex s)
{
this.vertexQueue = new PriorithizedVertexBuffer(this.distances);
BreadthFirstSearchAlgorithm algorithm = new BreadthFirstSearchAlgorithm(this.VisitedGraph, this.vertexQueue, this.Colors);
algorithm.InitializeVertex += this.InitializeVertex;
algorithm.DiscoverVertex += this.DiscoverVertex;
algorithm.ExamineEdge += this.ExamineEdge;
algorithm.ExamineVertex += this.ExamineVertex;
algorithm.FinishVertex += this.FinishVertex;
algorithm.TreeEdge += new EdgeEventHandler(this, (IntPtr) this.TreeEdge);
algorithm.GrayTarget += new EdgeEventHandler(this, (IntPtr) this.GrayTarget);
algorithm.Visit(s);
}
public void GraphWithSelfEdgesPUT2()
{
AdjacencyGraph g = null;
BreadthFirstSearchAlgorithm bfs = new BreadthFirstSearchAlgorithm(g);
}
private void breadthFirstSearchItem_Click(object sender, System.EventArgs e)
{
if (this.netronPanel.Graph==null)
throw new Exception("Generate a graph first");
if (this.netronPanel.Populator==null)
throw new Exception("Populator should not be null.");
ResetVertexAndEdgeColors();
// create algorithm
this.edgeColors=new EdgeColorDictionary();
foreach(IEdge edge in this.netronPanel.Graph.Edges)
this.edgeColors[edge]=GraphColor.White;
this.vertexColors = new VertexColorDictionary();
BreadthFirstSearchAlgorithm bfs = new BreadthFirstSearchAlgorithm(
this.netronPanel.Graph,
new VertexBuffer(),
this.vertexColors);
// create tracer
LayoutAlgorithmTraverVisitor tracer = new LayoutAlgorithmTraverVisitor(this.netronPanel.Populator);
// link to algo
bfs.RegisterTreeEdgeBuilderHandlers(tracer);
bfs.RegisterVertexColorizerHandlers(tracer);
bfs.TreeEdge +=new EdgeEventHandler(dfs_TreeEdge);
bfs.NonTreeEdge+=new EdgeEventHandler(dfs_BackEdge);
bfs.BlackTarget +=new EdgeEventHandler(dfs_ForwardOrCrossEdge);
// add handler to tracers
tracer.UpdateVertex +=new ShapeVertexEventHandler(tracer_UpdateVertex);
tracer.UpdateEdge +=new ConnectionEdgeEventHandler(tracer_UpdateEdge);
// running algorithm
VertexMethodCaller vm=
new VertexMethodCaller(
new ComputeVertexDelegate(bfs.Compute),
Traversal.FirstVertex(this.netronPanel.Graph)
);
Thread thread = new Thread(new ThreadStart(vm.Run));
thread.Start();
}
public void GraphWithSelfEdgesPUT(AdjacencyGraph g, int loopBound)
{
Random rnd = new Random();
Init();
for (int i = 0; i < loopBound; ++i)
{
for (int j = 0; j < i * i; ++j)
{
RandomGraph.Graph(g, i, j, rnd, true);
BreadthFirstSearchAlgorithm bfs = new BreadthFirstSearchAlgorithm(g);
bfs.InitializeVertex += new VertexHandler(this.InitializeVertex);
bfs.DiscoverVertex += new VertexHandler(this.DiscoverVertex);
bfs.ExamineEdge += new EdgeHandler(this.ExamineEdge);
bfs.ExamineVertex += new VertexHandler(this.ExamineVertex);
bfs.TreeEdge += new EdgeHandler(this.TreeEdge);
bfs.NonTreeEdge += new EdgeHandler(this.NonTreeEdge);
bfs.GrayTarget += new EdgeHandler(this.GrayTarget);
bfs.BlackTarget += new EdgeHandler(this.BlackTarget);
bfs.FinishVertex += new VertexHandler(this.FinishVertex);
Parents.Clear();
Distances.Clear();
m_CurrentDistance = 0;
m_SourceVertex = RandomGraph.Vertex(g, rnd);
var choose = PexChoose.FromCall(this);
if(choose.ChooseValue<bool>("to add a self ede"))
{
IVertex selfEdge = RandomGraph.Vertex(g, rnd);
g.AddEdge(selfEdge, selfEdge);
}
// g.RemoveEdge(RandomGraph.Edge(g, rnd));
foreach (IVertex v in g.Vertices)
{
Distances[v] = int.MaxValue;
Parents[v] = v;
}
Distances[SourceVertex] = 0;
bfs.Compute(SourceVertex);
CheckBfs(g, bfs);
}
}
}
