/// <summary>
/// Returns a List containing the two Vertices at either end of Edge e
/// </summary>
/// <param name="e"></param>
/// <returns></returns>
public List <Vertex> EndVertices(Edge e)
{
if (e == null || e.GetVertexA() == null || e.GetVertexB() == null)
{
return(null);
}
List <Vertex> endPoints = new List <Vertex>();
endPoints.Add(e.GetVertexA());
endPoints.Add(e.GetVertexB());
return(endPoints);
}
/// <summary>
/// Returns the origin of a directed Edge e
/// </summary>
/// <param name="e"></param>
/// <returns></returns>
public Vertex Origin(Edge e)
{
if (e == null)
{
return(null);
}
return(e.GetVertexA());
}
/// <summary>
/// Returns the opposite Vertex of Vertex v on Edge e
/// </summary>
/// <param name="v"></param>
/// <param name="e"></param>
/// <returns></returns>
public Vertex Opposite(Vertex v, Edge e)
{
if (v == null || e == null)
{
return(null);
}
if (e.GetVertexA().GetId() == v.GetId())
{
return(GetVertex(e.GetVertexB().GetId()));
}
else if (e.GetVertexB().GetId() == v.GetId())
{
return(GetVertex(e.GetVertexA().GetId()));
}
return(null);
}
/// <summary>
/// Returns whether Edge e is Directed or not
/// </summary>
/// <param name="e"></param>
/// <returns></returns>
public bool IsDirected(Edge e)
{
if (e == null)
{
return(false);
}
string other = e.GetVertexA().GetConnections().Find(id => id == e.GetVertexB().GetId());
Edge conj = e.Conjugate();
return(other == conj.GetVertexB().GetId());
}
