static void Main(string[] args)
{
NodeWrapper <string> ohio = new NodeWrapper <string>("Ohio");
NodeWrapper <string> nevada = new NodeWrapper <string>("Nevada");
NodeWrapper <string> losAngeles = new NodeWrapper <string>("Los Angeles");
NodeWrapper <string> canada = new NodeWrapper <string>("Canada");
NodeWrapper <string> greenland = new NodeWrapper <string>("Greenland");
NodeWrapper <string> southDakota = new NodeWrapper <string>("South Dakota");
NodeWrapper <string> denmark = new NodeWrapper <string>("Denmark");
//Americas nodes
ohio.AddNeighbor(nevada, 2);
ohio.AddNeighbor(losAngeles, 4);
losAngeles.AddNeighbor(canada, 2);
southDakota.AddNeighbor(losAngeles, 2);
nevada.AddNeighbor(canada, 3);
canada.AddNeighbor(greenland, 10);
greenland.AddNeighbor(denmark, 6);
PrintShortestRoute(ohio);
}
public Dictionary <NodeWrapper <T>, LinkedList <NodeWrapper <T> > > ShortestRouteToOthers()
{
//The dictionary that when finished will contain the shortest route to all of the Vs in the network
Dictionary <NodeWrapper <T>, LinkedList <NodeWrapper <T> > > shortestRoutes = new Dictionary <NodeWrapper <T>, LinkedList <NodeWrapper <T> > >();
//Dictionary that keeps track of Vs that have been the current
Dictionary <NodeWrapper <T>, bool> finishedVertex = new Dictionary <NodeWrapper <T>, bool>();
//Sorted list that keeps track of Vs with smallest distance from the starting V
SortedList <int, NodeWrapper <T> > next = new SortedList <int, NodeWrapper <T> >(new DuplicateKeyComparer <int>());
NodeWrapper <T> currentV = this;
LinkedList <NodeWrapper <T> > currentRoute = new LinkedList <NodeWrapper <T> >();
currentRoute.AddLast(currentV);
//O(n)
while (!finishedVertex.ContainsKey(currentV))
{
//O(n)/O(1) depending on length of Neighbors
foreach (NodeWrapper <T> v in currentV.Neighbors.Keys)
{
if (!finishedVertex.ContainsKey(v))
{
int distanceToStartV = sumOfRoute(currentRoute) + v.Neighbors[currentV];
LinkedList <NodeWrapper <T> > route = new LinkedList <NodeWrapper <T> >(currentRoute);
route.AddLast(v);
if (!shortestRoutes.ContainsKey(v))
{
//O(log(n))
next.Add(distanceToStartV, v);
//O(1)
shortestRoutes[v] = route;
}
else if (distanceToStartV < sumOfRoute(shortestRoutes[v]))
{
//O(1)
shortestRoutes[v] = route;
//O(n)
//Could be shortened to O(log(n)) by accessing next by key (by using sumOfRouteMethod)
int placementInNext = next.IndexOfValue(v);
next.RemoveAt(placementInNext);
//O(log(n))
next.Add(distanceToStartV, v);
}
}
}
//current will always be the Vertex with smallest distance to startV and therefore finished
finishedVertex[currentV] = true;
//update distanceFromStartV to distance of next Vertex
if (next.Count > 0)
{
currentV = next.First().Value;
currentRoute = shortestRoutes[currentV];
//Remove the new current from next list
next.RemoveAt(0);
}
}
return(shortestRoutes);
}
public void AddNeighbor(NodeWrapper <T> v, int distance)
{
Neighbors[v] = distance;
v.Neighbors[this] = distance;
}