private readonly Collections.Queue <EdgeW> _mst = new Collections.Queue <EdgeW>(); // edges in MST
/// <summary>
/// Compute a minimum spanning tree (or forest) of an edge-weighted graph.
/// </summary>
/// <param name="g">g the edge-weighted graph</param>
public KruskalMST(EdgeWeightedGraph g)
{
// more efficient to build heap by passing array of edges
var pq = new MinPQ <EdgeW>();
foreach (var e in g.Edges())
{
pq.Insert(e);
}
// run greedy algorithm
var uf = new UF(g.V);
while (!pq.IsEmpty() && _mst.Size() < g.V - 1)
{
var e = pq.DelMin();
var v = e.Either();
var w = e.Other(v);
if (!uf.Connected(v, w))
{ // v-w does not create a cycle
uf.Union(v, w); // merge v and w components
_mst.Enqueue(e); // add edge e to mst
_weight += e.Weight;
}
}
// check optimality conditions
//assert check(G);
}