private void FindPath(EdgeWeightedDigraph digraph, int start)
{
priorityQueue.Insert(start, 0f);
while (!priorityQueue.IsEmpty)
{
Relax(digraph, priorityQueue.DeleteMax());
}
}
protected virtual void Relax(EdgeWeightedDigraph digraph, int vertex)
{
foreach (var edge in digraph.Adjacent(vertex))
{
int w = edge.W;
if (distanceTo[w] > distanceTo[vertex] + edge.Weight)
{
distanceTo[w] = distanceTo[vertex] + edge.Weight;
edgeTo[w] = edge;
}
}
}
protected SP(EdgeWeightedDigraph digraph, int start)
{
this.start = start;
edgeTo = new DirectedEdge[digraph.VertexCount];
distanceTo = new float[digraph.VertexCount];
for (int v = 0; v < digraph.VertexCount; v++)
{
distanceTo[v] = float.MaxValue;
}
distanceTo[start] = 0f;
}
protected override void Relax(EdgeWeightedDigraph digraph, int vertex)
{
foreach (var edge in digraph.Adjacent(vertex))
{
int w = edge.W;
if (distanceTo[w] > distanceTo[vertex] + edge.Weight)
{
distanceTo[w] = distanceTo[vertex] + edge.Weight;
edgeTo[w] = edge;
if (priorityQueue.Contains(w))
{
priorityQueue.Change(w, distanceTo[w]);
}
else
{
priorityQueue.Insert(w, distanceTo[w]);
}
}
}
}
private static EdgeWeightedDigraph CreateGraph()
{
EdgeWeightedDigraph digraph = new EdgeWeightedDigraph(8);
digraph.AddEdge(4, 5, 35f);
digraph.AddEdge(5, 4, 35f);
digraph.AddEdge(4, 7, 37f);
digraph.AddEdge(5, 7, 28f);
digraph.AddEdge(7, 5, 28f);
digraph.AddEdge(5, 1, 32f);
digraph.AddEdge(0, 4, 38f);
digraph.AddEdge(0, 2, 26f);
digraph.AddEdge(7, 3, 39f);
digraph.AddEdge(1, 3, 29f);
digraph.AddEdge(2, 7, 34f);
digraph.AddEdge(6, 2, 40f);
digraph.AddEdge(3, 6, 52f);
digraph.AddEdge(6, 0, 58f);
digraph.AddEdge(6, 4, 93f);
return(digraph);
}
public Dijkstra(EdgeWeightedDigraph digraph, int start) : base(digraph, start)
{
priorityQueue = new IndexPriorityQueue <float>(digraph.VertexCount);
FindPath(digraph, start);
}