// Compute distance from startVertex to all other vertices
public void ComputeAllFromVertex(TVertex startVertex)
{
ComputedCosts[startVertex] = 0.0;
ComputedPaths[startVertex] = startVertex;
var remainingVertices = new HashSet <TVertex>(Graph.VertexIterator());
while (remainingVertices.Count > 0)
{
var currentVertex = popShortestRemaining(remainingVertices);
// Cost to get to current vertex
var cummulativeCost = ComputedCosts[currentVertex];
foreach (TEdge edgeToNeighbor in Graph.EdgeIterator(currentVertex))
{
var neighbor = edgeToNeighbor.End;
var neighborEdgeCost = EdgeCosts[edgeToNeighbor];
var neighborComputedCost = ComputedCosts[neighbor];
var costFromCurrent = cummulativeCost + neighborEdgeCost;
// Cost to neighbor is either what it already was, or the cost
// to get here plus the cost of the edge
if (costFromCurrent < neighborComputedCost)
{
ComputedCosts[neighbor] = costFromCurrent;
ComputedPaths[neighbor] = currentVertex;
}
}
}
}
public DijkstraShortestPath(AdjacencyListGraph <TVertex, TEdge> graph, Dictionary <TEdge, double> edgeCosts)
{
this.Graph = graph;
this.EdgeCosts = edgeCosts;
ComputedCosts = new Dictionary <TVertex, double>();
// The absence of a route entry in ComputedPaths means it's unreachable
ComputedPaths = new Dictionary <TVertex, TVertex>();
// Start every distance to infinity
foreach (TVertex vertex in Graph.VertexIterator())
{
ComputedCosts.Add(vertex, float.PositiveInfinity);
}
}
