public KruskalNode Root()
{
if (this.parent == null)
{
return(this);
}
KruskalNode newNode = this.parent.Root();
this.parent = newNode;
return(newNode);
}
private void Visualize_Click(object sender, EventArgs e)
{
kruskalTextLabel.Text = "";
ParseResults parsedResult = KruskalTextParser.ParseText(kruskalTextBox.Text);
points = new Point[parsedResult.numberOfVertices];
if (parsedResult.numberOfVertices > 0)
{
double angle = 360 / parsedResult.numberOfVertices;
points[0] = new Point(60, anchor.Y);
for (int i = 1; i < parsedResult.numberOfVertices; i++)
{
points[i] = RotatePoint(points[0], anchor, angle * i);
}
}
allEdges = parsedResult.allEdges;
try
{
Graph graph = new Graph(parsedResult.numberOfVertices);
foreach (Edge edge in allEdges)
{
graph.AddEdge(edge.from, edge.to, edge.weight);
}
kruskalEdges = KruskalNode.Kruskal(graph);
foreach (Edge edge in kruskalEdges)
{
kruskalTextLabel.Text += "" + edge.from + " -> " + edge.to + " = " + edge.weight + "\n";
}
}
catch
{
kruskalTextLabel.Text = "Couldn't execute Kruskal algorithm.";
}
panel1.Invalidate();
}
bool Merge(KruskalNode other)
{
KruskalNode rootThis = this.Root();
KruskalNode rootOther = other.Root();
if (rootThis == rootOther)
{
return(false);
}
if (rootThis.height < rootOther.height)
{
rootThis.parent = rootOther;
}
else
{
rootOther.parent = rootThis;
if (rootThis.height == rootOther.height)
{
rootThis.height += 1;
}
}
return(true); // merge successful
}
public static List <Edge> Kruskal(Graph graph)
{
int numberofVertices = graph.GetNumberOfVertices();
List <Edge> results = new List <Edge>();
int resultEdge = 0;
int currentSortedEdge = 0;
List <Edge> sortedEdges = graph.GetSortedEdges();
KruskalNode[] subSets = new KruskalNode[numberofVertices];
for (int i = 0; i < numberofVertices; i++)
{
subSets[i] = new KruskalNode();
//subSets[i].parent = null;
subSets[i].height = 0;
}
while (resultEdge < numberofVertices - 1)
{
Edge nextEdge = sortedEdges[currentSortedEdge++];
KruskalNode firstNode = subSets[nextEdge.from].Root();
KruskalNode secondNode = subSets[nextEdge.to].Root();
if (firstNode.Merge(secondNode))
{
results.Add(nextEdge);
resultEdge++;
}
}
//Print(results);
return(results);
}
bool InSameSet(KruskalNode other)
{
return(this.Root() == other.Root());
}
public KruskalNode()
{
this.parent = null;
this.height = 0;
}