/// <summary>
/// Performs a BFT of the graph with the given visitor and starting at the given vertex number.
/// </summary>
/// <param name="visitor"></param>
/// <param name="start"></param>
public virtual void BreadthFirstTraversal(IPrePostVisitor visitor, int start)
{
bool[] flags = new bool[mNumberOfVertices];
for (int i = 0; i < mNumberOfVertices; i++)
{
flags[i] = false;
}
IQueue queue = new QueueAsLinkedList();
queue.Enqueue(vertex[start]);
flags[start] = true;
while (!(queue.IsEmpty || visitor.IsDone))
{
IVertex vertex1 = (IVertex)queue.Dequeue();
visitor.PreVisit(vertex1);
Console.WriteLine("being in " + vertex1.Number);
IEnumerator iEnumerator = vertex1.Successors.GetEnumerator();
try
{
while (iEnumerator.MoveNext())
{
IVertex vertex2 = (IVertex)iEnumerator.Current;
if (!flags[vertex2.Number])
{
queue.Enqueue(vertex2);
visitor.Visit(vertex2);
Console.WriteLine("engueueing " + vertex2.Number);
flags[vertex2.Number] = true;
}
}
}
finally
{
IDisposable iDisposable = iEnumerator as IDisposable;
if (iDisposable != null)
{
iDisposable.Dispose();
}
}
visitor.PostVisit(vertex1);
}
}
/// <summary>
///
/// </summary>
/// <param name="tree"></param>
public static void BreadthFirstTraversal(ITree tree)
{
IQueue queue = new QueueAsLinkedList();
if (!tree.IsEmpty)
{
queue.Enqueue(tree);
}
while (!queue.IsEmpty)
{
ITree tree2 = (ITree)queue.Dequeue();
Console.WriteLine(tree2.Key);
for (int i = 0; i < tree2.Degree; i++)
{
ITree tree3 = tree2.GetSubtree(i);
if (!tree3.IsEmpty)
{
queue.Enqueue(tree3);
}
}
}
}
/// <summary>
/// Performs a BFT of the tree
/// </summary>
/// <param name="visitor"></param>
public virtual void BreadthFirstTraversal(IVisitor visitor)
{
QueueAsLinkedList queue = new QueueAsLinkedList();
if (!base.IsEmpty)
{
queue.Enqueue(this);
}
while (!queue.IsEmpty && !visitor.IsDone)
{
ITree tree1 = (ITree)queue.Dequeue();
visitor.Visit(tree1.Key);
for (int i = 0; i < tree1.Degree; i++)
{
ITree tree2 = tree1.GetSubtree(i);
if (!tree2.IsEmpty)
{
queue.Enqueue(tree2);
}
}
}
}
/// <summary>
/// This traversal visits the nodes of a directed graph in the order specified by a topological sort.
/// Informally, a topological sort is a list of the vertices of a (directed) graph in which all the successors
/// of any given vertex appear in the sequence after that vertex.
/// </summary>
/// <param name="visitor"></param>
public virtual void TopologicalOrderTraversal(IVisitor visitor)
{
int[] nums1 = new int[(uint)mNumberOfVertices];
for (int i1 = 0; i1 < mNumberOfVertices; i1++)
{
nums1[i1] = 0;
}
IEnumerator iEnumerator = Edges.GetEnumerator();
try
{
while (iEnumerator.MoveNext())
{
int[] nums2;
int k;
IVertex vertex1 = ((IEdge)iEnumerator.Current).V1;
(nums2 = nums1)[k = vertex1.Number]++;
}
}
finally
{
IDisposable iDisposable = iEnumerator as IDisposable;
if (iDisposable != null)
{
iDisposable.Dispose();
}
}
IQueue queue = new QueueAsLinkedList();
// a cyclic graph might not have an entry point without in-edges
//Thanks to Morton Mertner to fix this [email protected]
int inEdges = 0;
while (queue.IsEmpty || inEdges > mNumberOfEdges)
{
for (int j = 0; j < mNumberOfVertices; j++)
{
bool selectionCriteria = nums1[j] == inEdges;
if (inEdges > 0) // cyclic graph - add nodes with cyclic refs first
{
foreach (IEdge e in vertex[j].EmanatingEdges)
{
selectionCriteria &= e.V0.Number == e.V1.Number;
}
}
if (selectionCriteria)
{
queue.Enqueue(vertex[j]);
}
}
inEdges++;
}
while (!(queue.IsEmpty || visitor.IsDone))
{
IVertex vertex2 = (IVertex)queue.Dequeue();
visitor.Visit(vertex2);
iEnumerator = vertex2.Successors.GetEnumerator();
try
{
while (iEnumerator.MoveNext())
{
int[] nums2;
int k;
IVertex vertex3 = (IVertex)iEnumerator.Current;
if ((nums2 = nums1)[k = vertex3.Number]-- == 0)
{
queue.Enqueue(vertex3);
}
}
}
catch (Exception exc)
{
System.Diagnostics.Trace.WriteLine(exc.Message, "AbstractGraph.TopologicalOrderTraversal");
}
finally
{
IDisposable iDisposable = iEnumerator as IDisposable;
if (iDisposable != null)
{
iDisposable.Dispose();
}
}
}
}
internal Enumerator(QueueAsLinkedList queue)
{
this.queue = queue;
}