/// <summary>
/// Merge treeFrom with treeTo (this)
/// Copy all vertices over
/// Copy all edges over
/// </summary>
/// <param name="treeFrom">tree we are merging in</param>
private void MergeTrees(AGraph <T> treeFrom)
{
foreach (Vertex <T> v in treeFrom.EnumerateVertices())
{
this.AddVertex(v.Data);
//this.AddVertexAdjustEdges(v);
}
foreach (Edge <T> e in treeFrom.GetAllEdges())
{
this.AddEdge(e.From.data, e.To.data, e.Weight);
}
}
public IGraph <T> MinimumSpanningTree()
{
//Need to create an instance of the child class within the parent class. Don't know which child to create
//Possible Solutions
//1 - Create an abstract method where the child can return an instance of itself
//2 - Use C# Reflection to return an instance of the child utilizing the GetType()
AGraph <T> aGraph = null;
List <AGraph <T> > forest = new List <AGraph <T> >();
EdgeComparer comparer = new EdgeComparer();
List <Edge <T> > liEdges = new List <Edge <T> >();
Edge <T>[] edges = this.GetAllEdges();
foreach (Edge <T> e in edges)
{
liEdges.Add(e);
}
liEdges.Sort(comparer);
foreach (Vertex <T> v in vertices)
{
aGraph = (AGraph <T>)GetType().Assembly.CreateInstance(this.GetType().FullName);
aGraph.AddVertex(v.Data);
forest.Add(aGraph);
}
//while(liEdges.Count > 0 && forest.Count > 1)
//{
foreach (Edge <T> e in liEdges)
{
int fromIndex = forest.FindIndex(g => g.vertices.Contains(e.From));
int toIndex = forest.FindIndex(g => g.vertices.Contains(e.To));
if (fromIndex != toIndex && fromIndex != -1 && toIndex != -1)
{
forest[fromIndex].MergeTrees(forest[toIndex]);
forest[fromIndex].AddEdge(e.From.Data, e.To.Data, e.Weight);
forest.RemoveAt(toIndex);
}
}
//}
if (forest.Count == 1)
{
aGraph = forest[0];
}
return(aGraph);
}
/// <summary>
/// Given the forest (array of graphs), remove the location indicated by treeCut
/// </summary>
/// <param name="treeCut">Index of item to remove</param>
/// <param name="forest">Array of graphs</param>
/// <returns></returns>
private AGraph <T> [] Timber(int treeCut, AGraph <T>[] forest)
{
AGraph <T>[] tempForest = new AGraph <T> [forest.Length - 1];
int j = 0; //Loop counter for the new forest
for (int i = 0; i < forest.Length; i++)
{
if (i != treeCut)
{
tempForest[j++] = forest[i];
}
}
return(tempForest);
}
