/// <summary>
/// Used internally
/// </summary>
/// <param name="sender"></param>
/// <param name="args"></param>
private void FinishVertex(Object sender, VertexEventArgs args)
{
IVertex v = args.Vertex;
foreach (IEdge e in VisitedGraph.OutEdges(v))
{
IVertex w = e.Target;
if (this.Components[w] == int.MaxValue)
{
this.Roots[v] = MinDiscoverTime(this.Roots[v], this.Roots[w]);
}
}
if (Roots[v] == v)
{
IVertex w = null;
do
{
w = (IVertex)this.stack.Peek();
this.stack.Pop();
this.Components[w] = count;
}while (w != v);
++count;
}
}
//=======================================================================
// The main purpose of this routine is to set distance[v]
// to the smallest value allowed by the valid labeling constraints,
// which are:
// distance[t] = 0
// distance[u] <= distance[v] + 1 for every residual edge (u,v)
//
private int RelabelDistance(IVertex u)
{
int minEdges = 0;
workSinceLastUpdate += beta;
int minDistance = VisitedGraph.VerticesCount;
distances[u] = minDistance;
// Examine the residual out-edges of vertex i, choosing the
// edge whose target vertex has the minimal distance.
for (int ai = 0; ai < VisitedGraph.OutDegree(u); ai++)
{
++workSinceLastUpdate;
IEdge a = VisitedGraph.OutEdges(u)[ai];
IVertex v = a.Target;
if (IsResidualEdge(a) && distances[v] < minDistance)
{
minDistance = distances[v];
minEdges = ai;
}
}
++minDistance;
if (minDistance < n)
{
distances[u] = minDistance; // this is the main action
current[u] = minEdges;
maxDistance = Math.Max(minDistance, maxDistance);
}
return(minDistance);
}
/// <summary>
/// Creates a deep copy of an object using the supplied dictionary of visited objects as
/// a source of objects already encountered in the copy traversal. The dictionary of visited
/// objects is used for holding objects that have already been copied, to avoid erroneous
/// duplication of parts of the object graph.
/// </summary>
/// <param name="instance">The object to be copied.</param>
/// <param name="visited">The graph of objects visited so far.</param>
/// <returns></returns>
private static object Clone(this object instance, VisitedGraph visited)
{
if (instance == null)
return null;
Type instanceType = instance.GetType();
if(typeof(Type).IsAssignableFrom(instanceType))
{
return instance;
}
if (instanceType.IsPointer || instanceType == typeof(Pointer) || instanceType.IsPrimitive || instanceType == typeof(string))
return instance; // Pointers, primitive types and strings are considered immutable
if (instanceType.IsArray)
{
int length = ((Array)instance).Length;
Array copied = (Array)Activator.CreateInstance(instanceType, length);
visited.Add(instance, copied);
for (int i = 0; i < length; ++i)
copied.SetValue(((Array)instance).GetValue(i).Clone(visited), i);
return copied;
}
return Clone(instance, visited, DeduceInstance(instance));
}
/// <summary>
/// Execute the EDFS starting with the vertex s
/// </summary>
/// <param name="v">Starting vertex</param>
public void Compute(IVertex v)
{
if (v == null)
{
throw new ArgumentNullException("entry point");
}
Initialize();
// start whith him:
OnStartVertex(v);
// process each out edge of v
foreach (IEdge e in VisitedGraph.InEdges(v))
{
if (EdgeColors[e] == GraphColor.White)
{
OnStartEdge(e);
Visit(e, 0);
}
}
// process the rest of the graph edges
foreach (IEdge e in VisitedGraph.Edges)
{
if (EdgeColors[e] == GraphColor.White)
{
OnStartEdge(e);
Visit(e, 0);
}
}
}
private void OnVertexFinished([NotNull] TVertex vertex)
{
foreach (TEdge edge in VisitedGraph.OutEdges(vertex))
{
TVertex target = edge.Target;
if (Components[target] == int.MaxValue)
{
Roots[vertex] = MinDiscoverTime(Roots[vertex], Roots[target]);
}
}
if (Roots[vertex].Equals(vertex))
{
TVertex w;
do
{
w = _stack.Pop();
Components[w] = ComponentCount;
ComponentsPerStep.Add(ComponentCount);
VerticesPerStep.Add(w);
++Steps;
}while (!w.Equals(vertex));
++ComponentCount;
}
}
private void GenerateSpanningTree()
{
_spanningTree = new BidirectionalGraph <TVertex, Edge <TVertex> >(false);
_spanningTree.AddVertexRange(VisitedGraph.Vertices);
IQueue <TVertex> vb = new QuikGraph.Collections.Queue <TVertex>();
vb.Enqueue(VisitedGraph.Vertices.OrderBy(v => VisitedGraph.InDegree(v)).First());
switch (Parameters.SpanningTreeGeneration)
{
case SpanningTreeGeneration.BFS:
var bfs = new BreadthFirstSearchAlgorithm <TVertex, TEdge>(VisitedGraph, vb, new Dictionary <TVertex, GraphColor>());
bfs.TreeEdge += e =>
{
ThrowIfCancellationRequested();
_spanningTree.AddEdge(new Edge <TVertex>(e.Source, e.Target));
};
bfs.Compute();
break;
case SpanningTreeGeneration.DFS:
var dfs = new DepthFirstSearchAlgorithm <TVertex, TEdge>(VisitedGraph);
dfs.TreeEdge += e =>
{
ThrowIfCancellationRequested();
_spanningTree.AddEdge(new Edge <TVertex>(e.Source, e.Target));
};
dfs.Compute();
break;
}
}
/// <inheritdoc />
protected override void InternalCompute()
{
if (VisitedGraph.VertexCount == 0)
{
return;
}
if (TryGetRootVertex(out TVertex rootVertex))
{
AssertRootInGraph(rootVertex);
// Enqueue select root only
EnqueueRoot(rootVertex);
}
else
{
// Enqueue roots
foreach (TVertex root in VisitedGraph.Roots())
{
EnqueueRoot(root);
}
}
FlushVisitQueue();
}
private void AddReversedEdges([NotNull, ItemNotNull] IEnumerable <TEdge> notReversedEdges)
{
foreach (TEdge edge in notReversedEdges)
{
if (ReversedEdges.ContainsKey(edge))
{
continue;
}
// Already been added
if (FindReversedEdge(edge, out TEdge reversedEdge))
{
ReversedEdges[edge] = reversedEdge;
continue;
}
// Need to create one
reversedEdge = EdgeFactory(edge.Target, edge.Source);
if (!VisitedGraph.AddEdge(reversedEdge))
{
throw new InvalidOperationException("Cannot add the reversed edge, this should not arrive...");
}
_augmentedEdges.Add(reversedEdge);
ReversedEdges[edge] = reversedEdge;
ReversedEdges[reversedEdge] = edge;
OnReservedEdgeAdded(reversedEdge);
}
}
private bool TryGetSuccessor([NotNull] IDictionary <TEdge, int> visited, [NotNull] TVertex vertex, out TEdge successor)
{
IEnumerable <TEdge> outEdges = VisitedGraph.OutEdges(vertex);
IEnumerable <TEdge> edges = outEdges.Where(edge => !visited.ContainsKey(edge));
return(EdgeChain.TryGetSuccessor(edges, vertex, out successor));
}
private void FirstWalk([NotNull] TVertex vertex)
{
Debug.Assert(vertex != null);
BalloonData data = _data[vertex];
_visitedVertices.Add(vertex);
data.D = 0;
float s = 0;
foreach (TEdge edge in VisitedGraph.OutEdges(vertex))
{
TVertex otherVertex = edge.Target;
BalloonData otherData = _data[otherVertex];
if (!_visitedVertices.Contains(otherVertex))
{
FirstWalk(otherVertex);
data.D = Math.Max(data.D, otherData.R);
otherData.A = (float)Math.Atan((float)otherData.R / (data.D + otherData.R));
s += otherData.A;
}
}
AdjustChildren(data, s);
SetRadius(data);
}
private IEdgeEnumerable SelectOutEdgesNotInCircuit(IVertex v)
{
return(new FilteredEdgeEnumerable(
VisitedGraph.OutEdges(v),
new NotInCircuitEdgePredicate(Circuit, TemporaryCircuit)
));
}
static object Clone(object instance, VisitedGraph visited, object clone)
{
if (visited.ContainsKey(instance))
{
return(visited[instance]);
}
visited.Add(instance, clone);
Type type = instance.GetType();
while (type != null)
{
var ta = TypeAccessor.GetAccessor(type);
foreach (FieldInfo field in type.GetFields(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance))
{
object value = ta.GetField(field.Name, instance);
object cloneValue = visited.ContainsKey(value) ? visited[value] : Clone(value, visited);
ta.SetField(field.Name, clone, cloneValue);
}
type = type.BaseType;
}
return(clone);
}
protected virtual void GenerateSpanningTree(CancellationToken cancellationToken)
{
SpanningTree = new BidirectionalGraph <TVertex, Edge <TVertex> >(false);
SpanningTree.AddVertexRange(VisitedGraph.Vertices.OrderBy(v => VisitedGraph.InDegree(v)));
EdgeAction <TVertex, TEdge> action = e =>
{
cancellationToken.ThrowIfCancellationRequested();
SpanningTree.AddEdge(new Edge <TVertex>(e.Source, e.Target));
};
switch (Parameters.SpanningTreeGeneration)
{
case SpanningTreeGeneration.BFS:
var bfsAlgo = new BreadthFirstSearchAlgorithm <TVertex, TEdge>(VisitedGraph);
bfsAlgo.TreeEdge += action;
bfsAlgo.Compute();
break;
case SpanningTreeGeneration.DFS:
var dfsAlgo = new DepthFirstSearchAlgorithm <TVertex, TEdge>(VisitedGraph);
dfsAlgo.TreeEdge += action;
dfsAlgo.ForwardOrCrossEdge += action;
dfsAlgo.Compute();
break;
}
}
protected void AssertRootInGraph([NotNull] TVertex root)
{
if (!VisitedGraph.ContainsVertex(root))
{
throw new VertexNotFoundException("Root vertex is not part of the graph.");
}
}
private void ComputeNoInit([NotNull] TVertex root)
{
IEnumerable <TVertex> orderedVertices = VisitedGraph.TopologicalSort();
OnDiscoverVertex(root);
foreach (TVertex vertex in orderedVertices)
{
OnStartVertex(vertex);
OnExamineVertex(vertex);
foreach (TEdge edge in VisitedGraph.OutEdges(vertex))
{
OnExamineEdge(edge);
OnDiscoverVertex(edge.Target);
bool decreased = Relax(edge);
if (decreased)
{
OnTreeEdge(edge);
}
else
{
OnEdgeNotRelaxed(edge);
}
}
OnFinishVertex(vertex);
}
}
internal void ComputeNoInit(IVertex s)
{
VertexCollection orderedVertices = new VertexCollection();
TopologicalSortAlgorithm topoSorter = new TopologicalSortAlgorithm(VisitedGraph, orderedVertices);
topoSorter.Compute();
OnDiscoverVertex(s);
foreach (IVertex v in orderedVertices)
{
OnExamineVertex(v);
foreach (IEdge e in VisitedGraph.OutEdges(v))
{
OnDiscoverVertex(e.Target);
bool decreased = Relax(e);
if (decreased)
{
OnEdgeRelaxed(e);
}
else
{
OnEdgeNotRelaxed(e);
}
}
OnFinishVertex(v);
}
}
/// <summary>
/// Used internally
/// </summary>
/// <param name="sender"></param>
/// <param name="args"></param>
public void FinishVertex(Object sender, VertexEventArgs args)
{
IVertex v = args.Vertex;
foreach (IEdge e in VisitedGraph.OutEdges(v))
{
IVertex w = e.Target;
if (Components[w] == int.MaxValue)
{
Roots[v] = MinDiscoverTime(Roots[v], Roots[w]);
}
}
if (Roots[v] == v)
{
IVertex w = null;
do
{
w = (IVertex)m_Stack.Peek();
m_Stack.Pop();
Components[w] = m_Count;
}while (w != v);
++m_Count;
}
}
protected override void InternalCompute()
{
Initialize();
// start whith him:
if (this.RootVertex != null)
{
OnStartVertex(this.RootVertex);
// process each out edge of v
foreach (Edge e in VisitedGraph.OutEdges(this.RootVertex))
{
if (EdgeColors[e] == GraphColor.White)
{
OnStartEdge(e);
Visit(e, 0);
}
}
}
// process the rest of the graph edges
foreach (Edge e in VisitedGraph.Edges)
{
if (EdgeColors[e] == GraphColor.White)
{
OnStartEdge(e);
Visit(e, 0);
}
}
}
private void FirstWalk(TVertex v)
{
var data = _datas[v];
_visitedVertices.Add(v);
data.D = 0;
float s = 0;
foreach (var edge in VisitedGraph.OutEdges(v))
{
var otherVertex = edge.Target;
var otherData = _datas[otherVertex];
if (_visitedVertices.Contains(otherVertex))
{
continue;
}
FirstWalk(otherVertex);
data.D = Math.Max(data.D, otherData.R);
otherData.A = (float)Math.Atan(((float)otherData.R) / (data.D + otherData.R));
s += otherData.A;
}
AdjustChildren(v, data, s);
SetRadius(v, data);
}
/// <inheritdoc />
protected override void Initialize()
{
base.Initialize();
FoundNegativeCycle = false;
// Initialize colors and distances
VerticesColors.Clear();
foreach (TVertex vertex in VisitedGraph.Vertices)
{
VerticesColors[vertex] = GraphColor.White;
SetVertexDistance(vertex, double.PositiveInfinity);
OnInitializeVertex(vertex);
}
if (!TryGetRootVertex(out TVertex root))
{
// Try to fallback on first vertex, will throw if the graph is empty
root = VisitedGraph.Vertices.First();
}
else if (!VisitedGraph.ContainsVertex(root))
{
throw new VertexNotFoundException("Root vertex is not part of the graph.");
}
SetVertexDistance(root, 0);
}
private void SecondWalk([NotNull] TVertex vertex, double x, double y, float l, float t)
{
Debug.Assert(vertex != null);
var position = new Point(x, y);
VerticesPositions[vertex] = position;
_visitedVertices.Add(vertex);
BalloonData data = _data[vertex];
float dd = l * data.D;
float p = (float)(t + Math.PI);
int degree = VisitedGraph.OutDegree(vertex);
float fs = degree == 0 ? 0 : data.F / degree;
float pr = 0;
foreach (TEdge edge in VisitedGraph.OutEdges(vertex))
{
TVertex otherVertex = edge.Target;
if (_visitedVertices.Contains(otherVertex))
{
continue;
}
BalloonData otherData = _data[otherVertex];
float aa = data.C * otherData.A;
float rr = (float)(data.D * Math.Tan(aa) / (1 - Math.Tan(aa)));
p += pr + aa + fs;
float xx = (float)((l * rr + dd) * Math.Cos(p));
float yy = (l * rr + dd) * Math.Sign(p);
pr = aa;
SecondWalk(otherVertex, x + xx, y + yy, l * data.C, p);
}
}
/// <inheritdoc />
protected override void InternalCompute()
{
while (_heap.Count != 0)
{
ThrowIfCancellationRequested();
TVertex vertex = _heap.Dequeue();
if (InDegrees[vertex] != 0)
{
throw new NonAcyclicGraphException();
}
_sortedVertices.Add(vertex);
OnVertexAdded(vertex);
// Update the count of its adjacent vertices
foreach (TEdge edge in VisitedGraph.OutEdges(vertex))
{
--InDegrees[edge.Target];
Debug.Assert(InDegrees[edge.Target] >= 0);
_heap.Update(edge.Target);
}
}
SortedVertices = _sortedVertices.ToArray();
}
private void OnVertexFinished([NotNull] TVertex vertex)
{
foreach (TVertex target in VisitedGraph.OutEdges(vertex).Select(edge => edge.Target))
{
if (Components[target] == int.MaxValue)
{
Roots[vertex] = MinDiscoverTime(Roots[vertex], Roots[target]);
}
}
if (EqualityComparer <TVertex> .Default.Equals(Roots[vertex], vertex))
{
TVertex w;
do
{
w = _stack.Pop();
Components[w] = ComponentCount;
ComponentsPerStep.Add(ComponentCount);
VerticesPerStep.Add(w);
++Steps;
}while (!EqualityComparer <TVertex> .Default.Equals(w, vertex));
++ComponentCount;
}
}
private void FirstWalk(TVertex v)
{
var data = datas[v];
visitedVertices.Add(v);
data.d = 0;
float s = 0;
foreach (var edge in VisitedGraph.OutEdges(v))
{
var otherVertex = edge.Target;
var otherData = datas[otherVertex];
if (!visitedVertices.Contains(otherVertex))
{
FirstWalk(otherVertex);
data.d = Math.Max(data.d, otherData.r);
otherData.a = (float)Math.Atan(((float)otherData.r) / (data.d + otherData.r));
s += otherData.a;
}
}
AdjustChildren(v, data, s);
SetRadius(v, data);
}
private void SecondWalk(TVertex v, TVertex r, double x, double y, float l, float t)
{
Point pos = new Point(x, y);
VertexPositions[v] = pos;
visitedVertices.Add(v);
BalloonData data = datas[v];
float dd = l * data.d;
float p = (float)(t + Math.PI);
int degree = VisitedGraph.OutDegree(v);
float fs = (degree == 0 ? 0 : data.f / degree);
float pr = 0;
foreach (var edge in VisitedGraph.OutEdges(v))
{
var otherVertex = edge.Target;
if (visitedVertices.Contains(otherVertex))
{
continue;
}
var otherData = datas[otherVertex];
float aa = data.c * otherData.a;
float rr = (float)(data.d * Math.Tan(aa) / (1 - Math.Tan(aa)));
p += pr + aa + fs;
float xx = (float)((l * rr + dd) * Math.Cos(p));
float yy = (float)((l * rr + dd) * Math.Sign(p));
pr = aa;;
SecondWalk(otherVertex, v, x + xx, y + yy, l * data.c, p);
}
}
private bool FindAdjacentOddVertex(
TVertex u,
ICollection <TVertex> oddVertices,
EdgeFactory <TVertex, TEdge> edgeFactory,
out bool foundAdjacent)
{
bool found = false;
foundAdjacent = false;
foreach (TEdge edge in VisitedGraph.OutEdges(u))
{
TVertex v = edge.Target;
if (!EqualityComparer <TVertex> .Default.Equals(v, u) && oddVertices.Contains(v))
{
foundAdjacent = true;
// Check that v does not have an out-edge towards u
if (HasEdgeToward(u, v))
{
continue;
}
// Add temporary edge
AddTemporaryEdge(u, v, oddVertices, edgeFactory);
// Set u to null
found = true;
break;
}
}
return(found);
}
private void ExpandNode(
[NotNull] TVertex n,
[NotNull] IDictionary <TEdge, GraphColor> operators,
double cost,
[NotNull] BinaryHeap <double, TVertex> open)
{
// Skip self-edges
foreach (TEdge edge in VisitedGraph.OutEdges(n).Where(e => !e.IsSelfEdge()))
{
bool hasColor = operators.TryGetValue(edge, out GraphColor edgeColor);
if (!hasColor || edgeColor == GraphColor.White)
{
double weight = _edgeWeights(edge);
double nCost = _distanceRelaxer.Combine(cost, weight);
// (7) For each neighboring node of n' mark the operator from n to n' as used
// (8) For each node n', if there is no copy of n' in Open add it
// else save in open on the copy of n' with lowest cost. Mark as used all operators
// as used in any of the copies
operators[edge] = GraphColor.Gray;
if (open.MinimumUpdate(nCost, edge.Target))
{
OnTreeEdge(edge);
}
}
else
{
Debug.Assert(edgeColor == GraphColor.Gray);
// Edge already seen, remove it
operators.Remove(edge);
}
}
}
/// <inheritdoc />
protected override void InternalCompute()
{
if (!TryGetRootVertex(out TVertex root))
{
throw new InvalidOperationException("Root vertex not set.");
}
// Start with root vertex
OnStartVertex(root);
ICancelManager cancelManager = Services.CancelManager;
// Process each out edge of the root one
foreach (TEdge edge in VisitedGraph.OutEdges(root))
{
if (cancelManager.IsCancelling)
{
return;
}
if (!EdgesColors.ContainsKey(edge))
{
OnStartEdge(edge);
Visit(edge, 0);
}
}
}
private bool FindAdjacentOddVertex(
[NotNull] TVertex u,
[NotNull, ItemNotNull] List <TVertex> oddVertices,
[NotNull, InstantHandle] EdgeFactory <TVertex, TEdge> edgeFactory,
out bool foundAdjacent)
{
bool found = false;
foundAdjacent = false;
foreach (TEdge edge in VisitedGraph.OutEdges(u))
{
TVertex v = edge.Target;
if (!v.Equals(u) && oddVertices.Contains(v))
{
foundAdjacent = true;
// Check that v does not have an out-edge towards u
if (HasEdgeToward(u, v))
{
continue;
}
// Add temporary edge
AddTemporaryEdge(u, v, oddVertices, edgeFactory);
// Set u to null
found = true;
break;
}
}
return(found);
}
/// <inheritdoc />
protected override void Initialize()
{
base.Initialize();
if (!_reverserAlgorithm.Augmented)
{
throw new InvalidOperationException(
$"The graph has not been augmented yet.{Environment.NewLine}" +
$"Call {nameof(ReversedEdgeAugmentorAlgorithm<int, Edge<int>>)}.{nameof(ReversedEdgeAugmentorAlgorithm<int, Edge<int>>.AddReversedEdges)}() before running this algorithm.");
}
if (Source == null)
{
throw new InvalidOperationException("Source is not specified.");
}
if (Sink == null)
{
throw new InvalidOperationException("Sink is not specified.");
}
if (!VisitedGraph.ContainsVertex(Source))
{
throw new VertexNotFoundException("Source vertex is not part of the graph.");
}
if (!VisitedGraph.ContainsVertex(Sink))
{
throw new VertexNotFoundException("Sink vertex is not part of the graph.");
}
}
private void ExploreAdjacentEdges([NotNull] TVertex u)
{
foreach (TEdge edge in VisitedGraph.AdjacentEdges(u))
{
bool reversed = edge.Target.Equals(u);
TVertex v = reversed ? edge.Source : edge.Target;
OnExamineEdge(edge);
GraphColor vColor = VerticesColors[v];
if (vColor == GraphColor.White)
{
OnTreeEdge(edge, reversed);
VerticesColors[v] = GraphColor.Gray;
OnDiscoverVertex(v);
_vertexQueue.Enqueue(v);
}
else
{
OnNonTreeEdge(edge, reversed);
if (vColor == GraphColor.Gray)
{
OnGrayTarget(edge, reversed);
}
else
{
OnBlackTarget(edge, reversed);
}
}
}
}
/// <summary>
/// Creates a deep copy of an object using the supplied dictionary of visited objects as
/// a source of objects already encountered in the copy traversal. The dictionary of visited
/// objects is used for holding objects that have already been copied, to avoid erroneous
/// duplication of parts of the object graph.
/// </summary>
/// <param name="instance">The object to be copied.</param>
/// <param name="visited">The graph of objects visited so far.</param>
/// <returns></returns>
private static object Clone(this object instance, VisitedGraph visited)
{
if (instance == null)
return null;
Type instanceType = instance.GetType();
if (instanceType.IsValueType || instanceType == typeof(string))
return instance; // Value types and strings are immutable
else if (instanceType.IsArray)
{
int length = ((Array)instance).Length;
Array copied = (Array)Activator.CreateInstance(instanceType, length);
visited.Add(instance, copied);
for (int i = 0; i < length; ++i)
copied.SetValue(((Array)instance).GetValue(i).Clone(visited), i);
return copied;
}
else
return Clone(instance, visited, InstanceCreator.GetInstance(instanceType));
}
private static object Clone(this object instance, VisitedGraph visited, object copy)
{
if (visited.ContainsKey(instance))
return visited[instance];
else
visited.Add(instance, copy);
Type type = instance.GetType();
while (type != null)
{
foreach (FieldInfo field in type.GetFields(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance))
{
object value = field.GetValue(instance);
if (visited.ContainsKey(value))
field.SetValue(copy, visited[value]);
else
field.SetValue(copy, value.Clone(visited));
}
type = type.BaseType;
}
return copy;
}
private static object Clone(this object instance, VisitedGraph visited, object copy)
{
visited.Add(instance, copy);
var type = instance.GetType();
foreach (var field in GetTypeCopyableFieldList(type))
{
object value = field.Getter(instance);
object cloned;
if (value == null)
cloned = null;
else if (!visited.TryGetValue(value, out cloned))
cloned = value.Clone(visited);
field.Setter(copy, cloned);
}
return copy;
}
