/// <summary>
/// Records all the vertices that are part of the out-subtree of v
/// </summary>
/// <param name="g">visited graph</param>
/// <param name="v">root vertex</param>
/// <param name="maxDepth">Maximum exploration depth</param>
/// <returns></returns>
public static VertexCollection OutVertexTree(
IVertexListGraph g,
IVertex v,
int maxDepth
)
{
if (g == null)
{
throw new ArgumentNullException("g");
}
if (v == null)
{
throw new ArgumentNullException("v");
}
DepthFirstSearchAlgorithm dfs = new DepthFirstSearchAlgorithm(g);
dfs.BackEdge += new EdgeEventHandler(dfs_BackEdge);
VertexRecorderVisitor vis = new VertexRecorderVisitor();
vis.Vertices.Add(v);
dfs.TreeEdge += new EdgeEventHandler(vis.RecordTarget);
dfs.MaxDepth = maxDepth;
dfs.Initialize();
dfs.Visit(v, 0);
return(vis.Vertices);
}
public static void CloneOutVertexTree(
IVertexListGraph g,
ISerializableVertexAndEdgeListGraph sub,
IVertex v,
int maxDepth
)
{
if (g == null)
{
throw new ArgumentNullException("g");
}
if (sub == null)
{
throw new ArgumentNullException("sub");
}
if (v == null)
{
throw new ArgumentNullException("v");
}
DepthFirstSearchAlgorithm dfs = new DepthFirstSearchAlgorithm(g);
PopulatorVisitor pop = new PopulatorVisitor(sub);
dfs.StartVertex += new VertexEventHandler(pop.StartVertex);
dfs.TreeEdge += new EdgeEventHandler(pop.TreeEdge);
dfs.MaxDepth = maxDepth;
dfs.Initialize();
dfs.Visit(v, 0);
}
/// <summary>
/// Search strict dangling vertices, for example
/// |\
/// | \
/// |__\Y_________Z
/// In the above draft, Z is a dangling vertex, but Y is not.
/// </summary>
/// <returns></returns>
public IEnumerable <CurveVertex> SearchDanglingVertices()
{
// Search none loop vertices.
var noneLoopVertices = SearchNoneLoopVertices();
// Depth first search the graph, and find all the path end vertices.
var result = new HashSet <CurveVertex>();
var observer = new VertexPredecessorPathRecorderObserver <CurveVertex, SEdge <CurveVertex> >();
var dfs = new DepthFirstSearchAlgorithm <CurveVertex, SEdge <CurveVertex> >((IVertexListGraph <CurveVertex, SEdge <CurveVertex> >)_graph);
using (observer.Attach(dfs))
{
dfs.Compute();
}
// Dangling vertex must be an end path vertex.
foreach (var curveVertex in observer.EndPathVertices)
{
if (!noneLoopVertices.Contains(curveVertex))
{
continue;
}
result.Add(curveVertex);
// Check whether this path's root point is a dangling vertex.
var root = GetRootVertex(observer.VertexPredecessors, curveVertex);
if (root != null && noneLoopVertices.Contains(root.Value))
{
result.Add(root.Value);
}
}
return(result);
}
public IEnumerable <IEnumerable <SEdge <CurveVertex> > > SearchDanglingPaths()
{
// Search all none loop vertices
var noneLoopVertices = SearchNoneLoopVertices();
var danglingEdges = new List <SEdge <CurveVertex> >();
foreach (var vertex in noneLoopVertices)
{
IEnumerable <SEdge <CurveVertex> > edges = null;
if (_graph.TryGetOutEdges(vertex, out edges))
{
danglingEdges.AddRange(edges);
}
}
// Create a small graph.
var tempGraph = danglingEdges.ToAdjacencyGraph <CurveVertex, SEdge <CurveVertex> >();
// Deep first search the graph and get all its paths.
var observer = new VertexPredecessorPathRecorderObserver <CurveVertex, SEdge <CurveVertex> >();
var dfs = new DepthFirstSearchAlgorithm <CurveVertex, SEdge <CurveVertex> >((IVertexListGraph <CurveVertex, SEdge <CurveVertex> >)tempGraph);
using (observer.Attach(dfs))
{
dfs.Compute();
}
return(observer.AllPaths());
}
public void GraphWithSelfEdgesPUT1(int v, int e, bool self)
{
AdjacencyGraph g = null;
RandomGraph.Graph(g, v, e, new Random(), self);
DepthFirstSearchAlgorithm bfs = new DepthFirstSearchAlgorithm(g);
}
public void ClearRootVertex()
{
var graph = new AdjacencyGraph <int, Edge <int> >();
var algorithm = new DepthFirstSearchAlgorithm <int, Edge <int> >(graph);
ClearRootVertex_Test(algorithm);
}
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;
}
}
protected override void InternalCompute()
{
DepthFirstSearchAlgorithm <TVertex, TEdge> dfs = null;
try
{
dfs = new DepthFirstSearchAlgorithm <TVertex, TEdge>(
this,
this.VisitedGraph,
new Dictionary <TVertex, GraphColor>(this.VisitedGraph.VertexCount)
);
dfs.BackEdge += new EdgeAction <TVertex, TEdge>(this.BackEdge);
dfs.FinishVertex += new VertexAction <TVertex>(this.FinishVertex);
dfs.Compute();
}
finally
{
if (dfs != null)
{
dfs.BackEdge -= new EdgeAction <TVertex, TEdge>(this.BackEdge);
dfs.FinishVertex -= new VertexAction <TVertex>(this.FinishVertex);
}
}
}
private void TarjanOfflineLeastCommonAncestorAlgorithm <TVertex, TEdge>(
IVertexListGraph <TVertex, TEdge> g,
TVertex root,
SEquatableEdge <TVertex>[] pairs
)
where TEdge : IEdge <TVertex>
{
var lca = g.OfflineLeastCommonAncestorTarjan(root, pairs);
var predecessors = new VertexPredecessorRecorderObserver <TVertex, TEdge>();
var dfs = new DepthFirstSearchAlgorithm <TVertex, TEdge>(g);
using (predecessors.Attach(dfs))
dfs.Compute(root);
TVertex ancestor;
foreach (var pair in pairs)
{
if (lca(pair, out ancestor))
{
Assert.True(EdgeExtensions.IsPredecessor(predecessors.VertexPredecessors, root, pair.Source));
Assert.True(EdgeExtensions.IsPredecessor(predecessors.VertexPredecessors, root, pair.Target));
}
}
}
public RunPipeCollection AllTestPipes()
{
if (this.graph.VerticesCount == 1)
{
// only the root vertex
return(new RunPipeCollection());
}
DepthFirstSearchAlgorithm dfs = new DepthFirstSearchAlgorithm(
this.graph
);
// attach leaf recorder
PredecessorRecorderVisitor pred = new PredecessorRecorderVisitor();
dfs.RegisterPredecessorRecorderHandlers(pred);
dfs.Compute(this.Root);
// create pipies
RunPipeCollection pipes =
new RunPipeCollection();
foreach (EdgeCollection edges in pred.AllPaths())
{
RunPipe pipe = new RunPipe(this.Fixture);
foreach (IEdge e in edges)
{
pipe.Invokers.Add((RunInvokerVertex)e.Target);
}
pipes.Add(pipe);
}
return(pipes);
}
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 override void InternalCompute()
{
this.Components.Clear();
this.Roots.Clear();
this.DiscoverTimes.Clear();
componentCount = 0;
dfsTime = 0;
DepthFirstSearchAlgorithm <TVertex, TEdge> dfs = null;
try
{
dfs = new DepthFirstSearchAlgorithm <TVertex, TEdge>(
this,
VisitedGraph,
new Dictionary <TVertex, GraphColor>(this.VisitedGraph.VertexCount)
);
dfs.DiscoverVertex += new VertexEventHandler <TVertex>(this.DiscoverVertex);
dfs.FinishVertex += new VertexEventHandler <TVertex>(this.FinishVertex);
dfs.Compute();
}
finally
{
if (dfs != null)
{
dfs.DiscoverVertex -= new VertexEventHandler <TVertex>(this.DiscoverVertex);
dfs.FinishVertex -= new VertexEventHandler <TVertex>(this.FinishVertex);
}
}
}
protected override void InternalCompute()
{
DepthFirstSearchAlgorithm <TVertex, TEdge> dfs = null;
try
{
dfs = new DepthFirstSearchAlgorithm <TVertex, TEdge>(
this,
this.VisitedGraph,
new Dictionary <TVertex, GraphColor>(this.VisitedGraph.VertexCount)
);
dfs.BackEdge += BackEdge;
dfs.FinishVertex += VertexFinished;
dfs.DiscoverVertex += DiscoverVertex;
dfs.FinishVertex += FinishVertex;
dfs.Compute();
}
finally
{
if (dfs != null)
{
dfs.BackEdge -= BackEdge;
dfs.FinishVertex -= VertexFinished;
dfs.DiscoverVertex -= DiscoverVertex;
dfs.FinishVertex -= FinishVertex;
}
}
}
/// <inheritdoc />
protected override void InternalCompute()
{
// Shortcut for empty graph
if (VisitedGraph.IsVerticesEmpty)
{
return;
}
var dfs = new DepthFirstSearchAlgorithm <TVertex, TEdge>(VisitedGraph);
try
{
dfs.StartVertex += OnStartVertex;
dfs.TreeEdge += OnEdgeDiscovered;
dfs.ForwardOrCrossEdge += OnForwardOrCrossEdge;
dfs.Compute();
}
finally
{
dfs.StartVertex -= OnStartVertex;
dfs.TreeEdge -= OnEdgeDiscovered;
dfs.ForwardOrCrossEdge -= OnForwardOrCrossEdge;
}
}
public void FowardOrCrossEdge(Object sender, EdgeEventArgs args)
{
Assert.IsTrue(sender is DepthFirstSearchAlgorithm);
DepthFirstSearchAlgorithm algo = (DepthFirstSearchAlgorithm)sender;
Assert.AreEqual(algo.Colors[args.Edge.Target], GraphColor.Black);
}
/// <summary>
/// Computes a depth first tree.
/// </summary>
/// <typeparam name="TVertex">The type of the vertex.</typeparam>
/// <typeparam name="TEdge">The type of the edge.</typeparam>
/// <param name="visitedGraph">The visited graph.</param>
/// <param name="root">The root.</param>
/// <returns></returns>
public static TryFunc <TVertex, IEnumerable <TEdge> > TreeDepthFirstSearch <TVertex, TEdge>(
#if !NET20
this
#endif
IVertexListGraph <TVertex, TEdge> visitedGraph,
TVertex root)
where TEdge : IEdge <TVertex>
{
Contract.Requires(visitedGraph != null);
Contract.Requires(root != null);
Contract.Requires(visitedGraph.ContainsVertex(root));
Contract.Ensures(Contract.Result <TryFunc <TVertex, IEnumerable <TEdge> > >() != null);
var algo = new DepthFirstSearchAlgorithm <TVertex, TEdge>(visitedGraph);
var predecessorRecorder = new VertexPredecessorRecorderObserver <TVertex, TEdge>();
using (predecessorRecorder.Attach(algo))
algo.Compute(root);
var predecessors = predecessorRecorder.VertexPredecessors;
return(delegate(TVertex v, out IEnumerable <TEdge> edges)
{
return EdgeExtensions.TryGetPath(predecessors, v, out edges);
});
}
public void GraphWithoutSelfEdges()
{
AdjacencyGraph g = new AdjacencyGraph(
new QuickGraph.Providers.VertexAndEdgeProvider(),
true);
RandomGraph.Graph(g, 20, 100, new Random(), false);
DepthFirstSearchAlgorithm dfs = new DepthFirstSearchAlgorithm(g);
dfs.StartVertex += new VertexHandler(this.StartVertex);
dfs.DiscoverVertex += new VertexHandler(this.DiscoverVertex);
dfs.ExamineEdge += new EdgeHandler(this.ExamineEdge);
dfs.TreeEdge += new EdgeHandler(this.TreeEdge);
dfs.BackEdge += new EdgeHandler(this.BackEdge);
dfs.ForwardOrCrossEdge += new EdgeHandler(this.FowardOrCrossEdge);
dfs.FinishVertex += new VertexHandler(this.FinishVertex);
Parents.Clear();
DiscoverTimes.Clear();
FinishTimes.Clear();
m_Time = 0;
foreach (IVertex v in g.Vertices)
{
Parents[v] = v;
}
// compute
dfs.Compute();
CheckDfs(g, dfs);
}
public void SetRootVertex_Throws()
{
var graph = new AdjacencyGraph <TestVertex, Edge <TestVertex> >();
var algorithm = new DepthFirstSearchAlgorithm <TestVertex, Edge <TestVertex> >(graph);
SetRootVertex_Throws_Test(algorithm);
}
public void SolveReturnsAllSolutions()
{
var problem = new Problem();
var algorithm = new DepthFirstSearchAlgorithm();
var solutions = algorithm.Solve(problem);
}
public void ExamineEdge(Object sender, EdgeEventArgs args)
{
Assert.IsTrue(sender is DepthFirstSearchAlgorithm);
DepthFirstSearchAlgorithm algo = (DepthFirstSearchAlgorithm)sender;
Assert.AreEqual(algo.Colors[args.Edge.Source], GraphColor.Gray);
}
/// <inheritdoc />
protected override void InternalCompute()
{
DepthFirstSearchAlgorithm <TVertex, TEdge> dfs = null;
try
{
dfs = new DepthFirstSearchAlgorithm <TVertex, TEdge>(
this,
VisitedGraph,
new Dictionary <TVertex, GraphColor>(VisitedGraph.VertexCount));
dfs.BackEdge += OnBackEdge;
dfs.FinishVertex += OnVertexFinished;
dfs.DiscoverVertex += DiscoverVertex;
dfs.FinishVertex += FinishVertex;
dfs.Compute();
}
finally
{
if (dfs != null)
{
dfs.BackEdge -= OnBackEdge;
dfs.FinishVertex -= OnVertexFinished;
dfs.DiscoverVertex -= DiscoverVertex;
dfs.FinishVertex -= FinishVertex;
SortedVertices = _sortedVertices.Reverse().ToArray();
}
}
}
public void StartVertex(Object sender, VertexEventArgs args)
{
Assert.IsTrue(sender is DepthFirstSearchAlgorithm);
DepthFirstSearchAlgorithm algo = (DepthFirstSearchAlgorithm)sender;
Assert.AreEqual(algo.Colors[args.Vertex], GraphColor.White);
}
/// <inheritdoc />
protected override void InternalCompute()
{
DepthFirstSearchAlgorithm <TVertex, TEdge> dfs = null;
try
{
dfs = new DepthFirstSearchAlgorithm <TVertex, TEdge>(
this,
VisitedGraph,
new Dictionary <TVertex, GraphColor>(VisitedGraph.VertexCount));
dfs.DiscoverVertex += OnVertexDiscovered;
dfs.FinishVertex += OnVertexFinished;
dfs.Compute();
}
finally
{
if (dfs != null)
{
dfs.DiscoverVertex -= OnVertexDiscovered;
dfs.FinishVertex -= OnVertexFinished;
}
}
Debug.Assert(ComponentCount >= 0);
Debug.Assert(VisitedGraph.VertexCount >= 0 || ComponentCount == 0);
Debug.Assert(VisitedGraph.Vertices.All(v => Components.ContainsKey(v)));
Debug.Assert(VisitedGraph.VertexCount == Components.Count);
Debug.Assert(Components.Values.All(c => c <= ComponentCount));
}
private IReadOnlyCollection <IReadOnlyCollection <Identifier> > GetCyclePaths(IVertexListGraph <Identifier, SEquatableEdge <Identifier> > graph)
{
if (graph == null)
{
throw new ArgumentNullException(nameof(graph));
}
var examinedEdges = new List <IEdge <Identifier> >();
var cycles = new List <IReadOnlyCollection <Identifier> >();
var dfs = new DepthFirstSearchAlgorithm <Identifier, SEquatableEdge <Identifier> >(graph);
void onExamineEdge(SEquatableEdge <Identifier> e) => examinedEdges.Add(e);
void onCyclingEdgeFound(SEquatableEdge <Identifier> e) => OnCyclingEdgeFound(examinedEdges, cycles, e);
try
{
dfs.ExamineEdge += onExamineEdge;
dfs.BackEdge += onCyclingEdgeFound;
dfs.Compute();
return(cycles);
}
finally
{
dfs.ExamineEdge -= onExamineEdge;
dfs.BackEdge -= onCyclingEdgeFound;
}
}
//private VertexIntDictionary components;
///// <summary>
/// Initializes a new instance of the CompressNamespacesAlgorithm class.
/// </summary>
/// <param name="inputGraph"></param>
public CompressNamespacesAlgorithm(IVertexListGraph inputGraph)
{
this.visitedGraph = inputGraph;
dfs = new DepthFirstSearchAlgorithm(inputGraph);
dfs.FinishVertex += new VertexEventHandler(dfs_FinishVertex);
dfs.DiscoverVertex += new VertexEventHandler(dfs_DiscoverVertex);
dfs.TreeEdge += new EdgeEventHandler(dfs_TreeEdge);
}
public void FinishVertex(Object sender, VertexEventArgs args)
{
Assert.IsTrue(sender is DepthFirstSearchAlgorithm);
DepthFirstSearchAlgorithm algo = (DepthFirstSearchAlgorithm)sender;
Assert.AreEqual(algo.Colors[args.Vertex], GraphColor.Black);
FinishTimes[args.Vertex] = m_Time++;
}
public void TreeEdge(Object sender, EdgeEventArgs args)
{
Assert.IsTrue(sender is DepthFirstSearchAlgorithm);
DepthFirstSearchAlgorithm algo = (DepthFirstSearchAlgorithm)sender;
Assert.AreEqual(algo.Colors[args.Edge.Target], GraphColor.White);
Parents[args.Edge.Target] = args.Edge.Source;
}
public void ComputeWithRoot()
{
var graph = new AdjacencyGraph <int, Edge <int> >();
graph.AddVertex(0);
var algorithm = new DepthFirstSearchAlgorithm <int, Edge <int> >(graph);
ComputeWithRoot_Test(algorithm);
}
public void DiscoverVertex(Object sender, VertexEventArgs args)
{
Assert.IsTrue(sender is DepthFirstSearchAlgorithm);
DepthFirstSearchAlgorithm algo = (DepthFirstSearchAlgorithm)sender;
Assert.AreEqual(algo.Colors[args.Vertex], GraphColor.Gray);
Assert.AreEqual(algo.Colors[Parents[args.Vertex]], GraphColor.Gray);
DiscoverTimes[args.Vertex] = m_Time++;
}
public static IDictionary <int, double> Get(AdjacencyGraph <int, Edge <int> > g)
{
var dfs = new DepthFirstSearchAlgorithm <int, Edge <int> >(g);
var recorder = new VertexDistanceRecorderObserver <int, Edge <int> >(edgeWeights => 1.0);
using (recorder.Attach(dfs))
{
dfs.Compute();
return(recorder.Distances);
}
}
public static IDictionary <string, double> Get(AdjacencyGraph <string, TaggedEdge <string, string> > g)
{
var dfs = new DepthFirstSearchAlgorithm <string, TaggedEdge <string, string> >(g);
var recorder = new VertexDistanceRecorderObserver <string, TaggedEdge <string, string> >(edgeWeights => double.Parse(edgeWeights.Tag));
using (recorder.Attach(dfs))
{
dfs.Compute();
return(recorder.Distances);
}
}
