private void Run()
{
Func <Node, Node, double> cost = (u, v) => (Graph.Arcs(u, v, ArcFilter.Forward).Any() ? 1 : 10);
IEnumerable <Node> tour = null;
double minimumTourCost = Graph.NodeCount();
// Use the insertion tsp combined with 2-OPT heuristic.
InsertionTsp <Node> insertionTsp = new InsertionTsp <Node>(Graph.Nodes(), cost);
insertionTsp.Run();
if (insertionTsp.TourCost == minimumTourCost)
{
tour = insertionTsp.Tour;
}
else
{
Opt2Tsp <Node> opt2Tsp = new Opt2Tsp <Node>(cost, insertionTsp.Tour, insertionTsp.TourCost);
opt2Tsp.Run();
if (opt2Tsp.TourCost == minimumTourCost)
{
tour = opt2Tsp.Tour;
}
}
// convert the tour (node sequence) into a path (arc sequence connecting two nodes)
if (tour == null)
{
Cycle = null;
}
else
{
var cycle = new Path(Graph);
if (tour.Any())
{
Node prev = Node.Invalid;
foreach (var n in tour)
{
if (prev == Node.Invalid)
{
cycle.Begin(n);
}
else
{
cycle.AddLast(Graph.Arcs(prev, n, ArcFilter.Forward).First());
}
prev = n;
}
cycle.AddLast(Graph.Arcs(prev, tour.First(), ArcFilter.Forward).First());
} // if tour is not empty
Cycle = cycle;
}
}
private void Run()
{
Func <Node, Node, double> cost = (Node u, Node v) => (double)(Graph.Arcs(u, v, ArcFilter.Forward).Any() ? 1 : 10);
IEnumerable <Node> enumerable = null;
double num = (double)Graph.NodeCount();
InsertionTsp <Node> insertionTsp = new InsertionTsp <Node>(Graph.Nodes(), cost, TspSelectionRule.Farthest);
insertionTsp.Run();
if (insertionTsp.TourCost == num)
{
enumerable = insertionTsp.Tour;
}
else
{
Opt2Tsp <Node> opt2Tsp = new Opt2Tsp <Node>(cost, insertionTsp.Tour, insertionTsp.TourCost);
opt2Tsp.Run();
if (opt2Tsp.TourCost == num)
{
enumerable = opt2Tsp.Tour;
}
}
if (enumerable == null)
{
Cycle = null;
}
else
{
Path path = new Path(Graph);
if (enumerable.Any())
{
Node node = Node.Invalid;
foreach (Node item in enumerable)
{
if (node == Node.Invalid)
{
path.Begin(item);
}
else
{
path.AddLast(Graph.Arcs(node, item, ArcFilter.Forward).First());
}
node = item;
}
path.AddLast(Graph.Arcs(node, enumerable.First(), ArcFilter.Forward).First());
}
Cycle = path;
}
}
