protected override void visit(EdgeWeightedGraph graph, int v)
{
marked[v] = true;
foreach (Edge edge in graph.Adj(v))
{
int w = edge.Other(v);
if (marked[w]) continue;
if (edge.Weight < diestTo[w])
{
edgeTo[w] = edge;
diestTo[w] = edge.Weight;
if (pq.Contains(w))
{
pq.Change(w, diestTo[w]);
}
else
{
pq.Insert(w, diestTo[w]);
}
}
}
}
public void MinPQTest()
{
string[] graphItems = {
"4 5 0.35",
"4 7 0.37",
"5 7 0.28",
"0 7 0.16",
"1 5 0.32",
"0 4 0.38",
"2 3 0.17",
"1 7 0.19",
"0 2 0.26",
"1 2 0.36",
"1 3 0.29",
"2 7 0.34",
"6 2 0.40",
"3 6 0.52",
"6 0 0.58",
"6 4 0.93"
};
var graph = new EdgeWeightedGraph(8, 16, graphItems);
var pq = new MinPQ<Edge>();
foreach (Edge edge in graph.Edges())
{
pq.insert(edge);
}
while (pq.isEmpty() == false)
{
pq.delMin();
}
}
public void PrimMSTTest()
{
string[] graphItems = {
"4 5 0.35",
"4 7 0.37",
"5 7 0.28",
"0 7 0.16",
"1 5 0.32",
"0 4 0.38",
"2 3 0.17",
"1 7 0.19",
"0 2 0.26",
"1 2 0.36",
"1 3 0.29",
"2 7 0.34",
"6 2 0.40",
"3 6 0.52",
"6 0 0.58",
"6 4 0.93"
};
var graph = new EdgeWeightedGraph(8, 16, graphItems);
MST mst = new PrimMST(graph);
var builder = new StringBuilder();
foreach (Edge edge in mst.edges())
{
builder.AppendFormat("Edge {0}", edge);
}
Assert.AreEqual(1.81, mst.Weight);
}
protected override void visit(EdgeWeightedGraph graph, int v)
{
marked[v] = true;
foreach (Edge edge in graph.Adj(v))
{
if (!marked[edge.Other(v)]) pq.insert(edge);
}
}
public LazyPrimMST(EdgeWeightedGraph graph)
{
pq = new MinPQ<Edge>();
marked = new bool[graph.V];
mst = new Queue<Edge>();
visit(graph, 0);
while (!pq.isEmpty())
{
Edge e = pq.delMin();
int v = e.Either, w = e.Other(v);
if (marked[v] && marked[w]) continue;
mst.Enqueue(e);
if (!marked[v]) visit(graph, v);
if (!marked[w]) visit(graph, w);
}
}
public PrimMST(EdgeWeightedGraph graph)
{
edgeTo = new Edge[graph.V];
diestTo = new double[graph.V];
marked = new bool[graph.V];
for (int v = 0; v < graph.V; v++)
{
diestTo[v] = double.MaxValue;
}
pq = new IndexMinPq<double>(graph.V);
diestTo[0] = 0;
pq.Insert(0, 0);
while (!pq.IsEmpty())
{
visit(graph, pq.DelMin());
}
}
protected abstract void visit(EdgeWeightedGraph graph, int v);