public static void Solve(int vehicles, int capacity, Distance distances, Demands demands)
{
/*
* Generate constraint model
*/
// Third argument defines depot, i.e. start-end node for round trip.
var model = new RoutingModel(distances.MapSize(), vehicles, 0);
// Node costs vs. Arc Costs
model.SetArcCostEvaluatorOfAllVehicles(distances);
/*
* Capacity Constraints
*/
if (distances.MapSize() != demands.MapSize())
{
throw new ArgumentException("Define demand for each city.");
}
model.AddDimension(demands, 0, capacity, true, "capacity");
/*
* Solve problem and display solution
*/
Assignment assignment = model.Solve();
if (assignment != null)
{
Console.WriteLine("Depot: " + model.GetDepot());
Console.WriteLine("Total Distance: " + assignment.ObjectiveValue() + "\n");
for (int i = 0; i < vehicles; i++)
{
/*
* Display Trips:
*/
Console.WriteLine("Round Trip for Vehicle " + i + ":");
long total = 0;
var source = model.Start(i);
while (!model.IsEnd(source))
{
var s = model.IndexToNode(source);
var t = model.IndexToNode(model.Next(assignment, source));
total += distances.Run(s, t);
Console.WriteLine(String.Format(" - From {0,-2} (demand: {1,-1}) travel to {2,-2} (demand: {3,-1}) with distance: {4,-2}",
distances.ToString(s),
demands.Demand(s),
distances.ToString(t),
demands.Demand(t),
distances.Run(s, t)));
source = model.Next(assignment, source);
}
Console.WriteLine("Total Distance for Vehicle " + i + ": " + total + "\n");
}
}
Console.ReadKey();
}
