/// <summary>
/// Get path from @from to @to
/// </summary>
/// <param name="from">Start node</param>
/// <param name="to">End node</param>
/// <returns>Value with path</returns>
public virtual IShortestPathResult Process(uint from, uint to)
{
var result = new DijkstraResult(from, to);
Graph[from].Distance = 0;
var q = new SortedSet <INode <T, TEdgeCustom> >(new[] { Graph[from] }, new NodeComparer <T, TEdgeCustom>());
var current = new HashSet <uint>();
while (q.Count > 0)
{
INode <T, TEdgeCustom> u = q.Deque();
current.Remove(u.Key);
if (u.Key == to)
{
result.Distance = u.Distance;
break;
}
u.EachChild((in Edge <T, TEdgeCustom> e) =>
{
if (e.Node.Distance > u.Distance + e.Cost)
{
if (current.Contains(e.Node.Key))
{
q.Remove(e.Node);
}
e.Node.Distance = u.Distance + e.Cost;
q.Add(e.Node);
current.Add(e.Node.Key);
result.Path[e.Node.Key] = u.Key;
}
});
//calculates the shorted path
public static void shortest(TextBox cost, TextBox arrayTimeBox, TextBox heapTimeBox, TextBox xspeedupBox, int startingIndex, List <PointF> points
, List <HashSet <int> > connections, int stopIndex, Graphics graphics, bool compare)
{
DijkstraResult heapResult = dijkstra(startingIndex, points, connections, PriorityQueueFactory.QueueType.Heap);
//Grabbing the results of dijkstra
List <int> prev = heapResult.getPrev();
List <double> dist = heapResult.getDist();
int currentIndex = stopIndex;
bool isPath = true;
//iterating through the result to make sure a complete path exists and to draw the path
while (currentIndex != startingIndex)
{
//if the path doesn't exist then there is no reason to continue, and the cost is unreachable
if (currentIndex != startingIndex && prev[currentIndex] == -1)
{
isPath = false;
break;
}
PointF previousNode = points[prev[currentIndex]];
PointF currentNode = points[currentIndex];
graphics.DrawLine(Pens.Black, currentNode, previousNode);
double distance = dist[currentIndex] - dist[prev[currentIndex]];
graphics.DrawString(String.Format("{0}", (int)distance), SystemFonts.DefaultFont, Brushes.Black, midpoint(currentNode, previousNode));
currentIndex = prev[currentIndex];
}
if (isPath)
{
//if the user wants to compare the array to the binary heap times we have to do dijkstras with the array
if (compare)
{
DijkstraResult arrayResult = dijkstra(startingIndex, points, connections, PriorityQueueFactory.QueueType.Array);
arrayTimeBox.Text = String.Format("{0}", arrayResult.getTime());
xspeedupBox.Text = String.Format("{0}", arrayResult.getTime() / heapResult.getTime());
}
cost.Text = String.Format("{0}", (int)dist.Last());
heapTimeBox.Text = String.Format("{0}", heapResult.getTime());
}
else
{
cost.Text = "Unreachable";
}
}
