public static List <Node> Dijkstra(Graph graph, Dictionary <Edge, double> weights, Node start, Node end)
{
var notVisited = graph.Nodes.ToList();
var track = new Dictionary <Node, DijkstraData>();
track[start] = new DijkstraData {
Price = 0, Previous = null
};
while (true)
{
Node toOpen = null;
var bestPrice = double.PositiveInfinity;
foreach (var e in notVisited)
{
if (track.ContainsKey(e) && track[e].Price < bestPrice)
{
bestPrice = track[e].Price;
toOpen = e;
}
}
if (toOpen == null)
{
return(null);
}
if (toOpen.Equals(end))
{
end = toOpen;
break;
}
foreach (var e in toOpen.IncidentEdges.Where(z => z.From == toOpen))
{
var currentPrice = track[toOpen].Price + weights[e];
var nextNode = e.OtherNode(toOpen);
if (!track.ContainsKey(nextNode) || track[nextNode].Price > currentPrice)
{
track[nextNode] = new DijkstraData {
Previous = toOpen, Price = currentPrice
};
}
}
notVisited.Remove(toOpen);
}
var result = new List <Node>();
while (end != null)
{
result.Add(end);
end = track[end].Previous;
}
result.Reverse();
return(result);
}
public static DijkstraAnswer DijkstraAlgo(Graph graph, Node start, Node end, List <Node> eliminated)
{
var notVisited = graph.Nodes.ToList();
var track = new Dictionary <Node, DijkstraData>();
track[start] = new DijkstraData {
Price = 0, Previous = null
};
while (true)
{
Node toOpen = null;
var bestPrice = double.PositiveInfinity;
foreach (var e in notVisited)
{
if (!eliminated.Contains(e) && track.ContainsKey(e) && track[e].Price < bestPrice)
{
bestPrice = track[e].Price;
toOpen = e;
}
}
if (toOpen == null)
{
return(null);
}
if (toOpen == end)
{
break;
}
foreach (var e in toOpen.IncidentEdges)
{
var currentPrice = track[toOpen].Price + e.Weight;
var nextNode = e.OtherNode(toOpen);
if (!track.ContainsKey(nextNode) || currentPrice < track[nextNode].Price)
{
track[nextNode] = new DijkstraData {
Previous = toOpen, Price = currentPrice
};
}
}
notVisited.Remove(toOpen);
}
var result = new List <Node>();
var price = track[end].Price;
while (end != null)
{
result.Add(end);
end = track[end].Previous;
}
result.Reverse();
return(new DijkstraAnswer(result, price));
}
