public EdgeDS[] KruskalMST()
{
// This will store the resultant MST
EdgeDS[] mstEdges = new EdgeDS[myGraph.V - 1];
for (int i = 0; i < myGraph.V - 1; i++)
{
mstEdges[0] = new EdgeDS();
}
// Step 1: Sort all the edges in non-decreasing order of their weight.
// If we are not allowed to change the given graph, we can create a copy of array of edges.
Array.Sort(myGraph.Edges);
// Step 2: Allocate memory for creating V ssubsets
SubsetDS[] subsets = new SubsetDS[myGraph.V];
for (int i = 0; i < myGraph.V; i++)
{
subsets[i] = new SubsetDS(i, 0);
}
// Step 3: Number of Edges to be taken is V - 1
int edgesCounter = 0;
int nERequired = 0;
while (nERequired < myGraph.V - 1)
{
// Step 4: Pick the smallest edge. And increment the index for next iteration
EdgeDS edge = new EdgeDS();
edge = myGraph.Edges[edgesCounter++];
int xRoot = myGraph.FindRoot(subsets, edge.Src);
int yRoot = myGraph.FindRoot(subsets, edge.Dest);
// Step 5: If including this edge does't cause cycle, include it in result and increment the index of result for next edge
if (xRoot != yRoot)
{
mstEdges[nERequired++] = edge;
myGraph.DoUnion(subsets, xRoot, yRoot);
}
}
return(mstEdges);
}
public bool HasCycle()
{
SubsetDS[] subsets = new SubsetDS[this.V];
for (int i = 0; i < this.V; i++)
{
subsets[i] = new SubsetDS(i, 0);
}
for (int i = 0; i < this.E; i++)
{
int xRoot = FindRoot(subsets, this.Edges[i].Src);
int yRoot = FindRoot(subsets, this.Edges[i].Dest);
if (xRoot == yRoot)
{
return(true);
}
DoUnion(subsets, xRoot, yRoot);
}
return(false);
}
