/// <summary>
/// Draw a new edge.
/// </summary>
private void Vertex_MouseDown_DrawEdge(object sender, MouseEventArgs e)
{
if (selectedTool == "buttonEdge")
{
(sender as Vertex).SetDraggable(false);
if (vStart == null)
{
vStart = (sender as Vertex);
}
else
{
vFinish = (sender as Vertex);
if (isDirected)
{
vStart.SetEdge(vFinish);
mapMatrix.SetDirectedEdge(vStart.GetNumberIndex(), vFinish.GetNumberIndex());
mapList.SetDirectedEdge(vStart.GetNumberIndex(), vFinish.GetNumberIndex());
}
else
{
vStart.SetEdge(vFinish);
vFinish.SetEdge(vStart);
mapMatrix.SetUndirectedEdge(vStart.GetNumberIndex(), vFinish.GetNumberIndex());
mapList.SetUndirectedEdge(vStart.GetNumberIndex(), vFinish.GetNumberIndex());
}
vStart.SetSelected(false);
vFinish.SetSelected(false);
vStart.Refresh();
vFinish.Refresh();
ResetBoard();
vStart = null;
vFinish = null;
}
}
}
// Trees (Group A) are implemented here.
// Graph/Tree Traversal (Group A) is implemented here.
// Complex user-defined algorithm (Group A) is implemented here.
/// <summary>
/// Returns the the Minimum Spanning Tree of the graph, in the form of adjacency list, using Kruskal's algorithm.
/// </summary>
public AdjacencyList Kruskal_GetTree_List()
{
if (!CheckUndirectedGraph())
{
MessageBox.Show("Error in finding the Minimum Spanning Tree: \nThe graph is not undirected!");
return(null);
}
else
{
AdjacencyList outputMST = new AdjacencyList();
int count = 0;
InitialiseEdges();
InitialiseUnionFind();
QuickSort(edges, 0, edges.Count - 1);
while (count < Count() - 1)
{
if (Find(edges[0].vStart).GetLeader() != Find(edges[0].vFinish).GetLeader())
{
count++;
outputMST.SetUndirectedEdge(edges[0].vStart, edges[0].vFinish, edges[0].weight);
Union(Find(edges[0].vStart).GetLeader(), Find(edges[0].vFinish).GetLeader());
}
edges.RemoveAt(0);
}
return(outputMST);
}
}
// Trees (Group A) are implemented here.
// Graph/Tree Traversal (Group A) is implemented here.
// Complex user-defined algorithm (Group A) is implemented here.
/// <summary>
/// Returns the the Minimum Spanning Tree of the graph, in the form of adjacency list, using Prim's algorithm.
/// </summary>
/// <param name="vStart">The starting vertex.</param>
public AdjacencyList Prim_GetTree_List(int vStart)
{
if (!CheckUndirectedGraph())
{
MessageBox.Show("Error in finding the Minimum Spanning Tree: \nThe graph is not undirected!");
return(null);
}
else
{
List <int> visitedVertices = new List <int>();
List <int> remainingVertices = new List <int>();
AdjacencyList outputMST = new AdjacencyList();
for (int i = 0; i < this.GetSize(); i++)
{
if (this.IsVertexExisting(i))
{
remainingVertices.Add(i);
}
}
visitedVertices.Add(vStart);
remainingVertices.Remove(vStart);
while (remainingVertices.Any())
{
double min = Double.MaxValue;
int newVStart = -1, newVFinish = -1;
foreach (int i in visitedVertices)
{
foreach (int j in remainingVertices)
{
if (ContainsEdge(i, j) && GetEdge(i, j) < min)
{
min = GetEdge(i, j);
newVStart = i;
newVFinish = j;
}
}
}
visitedVertices.Add(newVFinish);
remainingVertices.Remove(newVFinish);
outputMST.SetUndirectedEdge(newVStart, newVFinish, min);
}
return(outputMST);
}
}