/// <summary>
/// Performs the Depth First Search start from specified vertex.
/// </summary>
/// <param name="s">The depth first search start vertex.</param>
public void PerformDFS(Vertex s)
{
// White marks vertices that have yet to be discovered.
foreach (var u in _graph.Vertices) {
u.Mark = VertexMarks.White;
}
// if there is a starting vertex, start from it:
if (s != null) {
VisitDFS(s);
}
// process each vertex
foreach (var u in _graph.Vertices) {
if (u.Mark == VertexMarks.White) {
VisitDFS(u);
}
}
}
/// <summary>
/// Performs the Breadth First Search start from specified vertex.
/// </summary>
/// <param name="s">The s.</param>
public void PerformBFS(Vertex s)
{
}
private void VisitDFS(Vertex u)
{
if (u == null)
throw new ArgumentNullException("u", "Vertex cannot be null!");
// Gray marks a vertex that is discovered
// but still has vertices adjacent to it that are undiscovered.
u.Mark = VertexMarks.Gray;
Vertex v = null;
for (var edge = u.FirstOut; edge != null; edge = edge.NextOut) {
v = edge.In;
if (v.Mark == VertexMarks.White) {
VisitDFS(v);
edge.Type = EdgeType.TreeEdge;
}
else if (v.Mark == VertexMarks.Gray) {
edge.Type = EdgeType.BackEdge;
}
else {
edge.Type = EdgeType.ForwardEdge;
}
}
// Black marks vertex is discovered vertex that is not adjacent to any white vertices.
u.Mark = VertexMarks.Black;
}
/// <summary>
/// Adds a new <see cref="Edge" /> with the out and in vertices to the graph and returns it.
/// </summary>
/// <param name="out">The out vertex to create edge.</param>
/// <param name="in">The in vertex to create edge.</param>
/// <returns>
/// The new edge added to the graph.
/// </returns>
public Edge AddEdge(Vertex @out, Vertex @in)
{
bool exist = false;
foreach (var edge in _edgeList) {
if (edge.Out == @out && edge.In == @in) {
exist = true;
break;
}
}
if (!exist) {
// create edge
var edge = _factory.NewEdge(@out, @in);
_edgeList.Add(edge);
return edge;
}
return null;
}
/// <summary>
/// Removes the <see cref="Vertex" /> from the graph.
/// </summary>
/// <param name="v">The vertex.</param>
public void RemoveVertex(Vertex v)
{
if (!_vertexList.Contains(v)) {
_vertexList.Remove(v);
}
}
/// <summary>
/// Adds a new <see cref="Vertex" /> to the graph and returns it.
/// </summary>
/// <param name="v">The vertex.</param>
public void AddVertex(Vertex v)
{
if (!_vertexList.Contains(v)) {
_vertexList.Add(v);
}
}