private IEnumerable <IBlock> ShortestPathBlocks(IBlock start, IBlock end)
{
yield return(null);
IEnumerable <DirectedEdge> path = DijkstraShortestPath.FindPath(_graph, IndexFor(start), IndexFor(end));
if (path == null)
{
yield return(null);
}
else
{
yield return(start);
foreach (DirectedEdge edge in path)
{
yield return(BlockFor(edge.To));
}
}
}
/// <summary>
/// Returns an IEnumerable of DirectedEdges representing a shortest path from the specified sourceVertex to the specified destinationVertex
/// This is more efficent than creating a new DijkstraShorestPath instance and calling PathTo( destinationVertex ) when we only
/// want a single path from Source to Destination and don't want many paths from the source to multiple different destinations.
/// </summary>
/// <param name="graph">The edge-weighted directed graph</param>
/// <param name="sourceVertex">The source vertext to find a shortest path from</param>
/// <param name="destinationVertex">The destination vertex to find a shortest path to</param>
public static IEnumerable <DirectedEdge> FindPath(EdgeWeightedDigraph graph, int sourceVertex, int destinationVertex)
{
var dijkstraShortestPath = new DijkstraShortestPath(graph, sourceVertex, destinationVertex);
return(dijkstraShortestPath.PathTo(destinationVertex));
}