static void Solve(int size, int forbidden, int seed) { RoutingModel routing = new RoutingModel(size, 1); // Setting first solution heuristic (cheapest addition). routing.SetFirstSolutionStrategy(RoutingModel.ROUTING_PATH_CHEAPEST_ARC); // Setting the cost function. // Put a permanent callback to the distance accessor here. The callback // has the following signature: ResultCallback2<int64, int64, int64>. // The two arguments are the from and to node inidices. RandomManhattan distances = new RandomManhattan(size, seed); routing.SetCost(distances); // Forbid node connections (randomly). Random randomizer = new Random(); long forbidden_connections = 0; while (forbidden_connections < forbidden) { long from = randomizer.Next(size - 1); long to = randomizer.Next(size - 1) + 1; if (routing.NextVar(from).Contains(to)) { Console.WriteLine("Forbidding connection {0} -> {1}", from, to); routing.NextVar(from).RemoveValue(to); ++forbidden_connections; } } // Add dummy dimension to test API. routing.AddDimension(new ConstantCallback(), size + 1, size + 1, true, "dummy"); // Solve, returns a solution if any (owned by RoutingModel). Assignment solution = routing.Solve(); if (solution != null) { // Solution cost. Console.WriteLine("Cost = {0}", solution.ObjectiveValue()); // Inspect solution. // Only one route here; otherwise iterate from 0 to routing.vehicles() - 1 int route_number = 0; for (long node = routing.Start(route_number); !routing.IsEnd(node); node = solution.Value(routing.NextVar(node))) { Console.Write("{0} -> ", node); } Console.WriteLine("0"); } }
public override void Solve() { var pparser = new Pparser(FpatIn); int n, l; pparser.Fetch(out n, out l); var rgnode = pparser.FetchN <string>(n); rgnode.Insert(0, "X"); var model = new RoutingModel(n, 1); model.SetFirstSolutionStrategy(RoutingModel.ROUTING_GLOBAL_CHEAPEST_ARC); //model.SetMetaheuristic(RoutingModel.ROUTING_TABU_SEARCH); model.SetCost(new NodeEval(rgnode.ToArray())); model.SetDepot(0); for (int i = 0; i < n; i++) { var varI = model.NextVar(i); for (int j = 0; j < n; j++) { if (i == j) { continue; } if (!NodeEval.FMatch(rgnode[i], rgnode[j])) { varI.RemoveValue(j); } } } Console.WriteLine("solving"); Assignment solution = model.Solve(); model.UpdateTimeLimit(1000 * 60 * 3); if (solution != null) { // Solution cost. Console.WriteLine("Cost = {0}", solution.ObjectiveValue()); for (var inode = (int)model.Start(0); !model.IsEnd(inode); inode = (int)solution.Value(model.NextVar(inode))) { Console.WriteLine(rgnode[inode]); } Console.WriteLine("0"); } }
/* * Number of Vehicles: */ public static void Solve(int vehicles, string pathToXml = null) { /* * Add custom distance function */ var dist = (pathToXml == null) ? new Distance() : new XmlDistance(pathToXml); /* * Generate constraint model */ // Third argument defines depot, i.e. start-end node for round trip. var model = new RoutingModel(dist.MapSize(), vehicles, 0); model.SetCost(dist); /* * This modification forces all Vehicles to visit at least one city. */ /*for (int i = 0; i < Vehicles; i++) { * * IntVar first = model.NextVar(model.Start(i)); * first.SetMax(dist.MapSize() - 1); * } * * /* * Solve problem and display solution */ Assignment assignment = model.Solve(); if (assignment != null) { Console.WriteLine("Total Distance: " + assignment.ObjectiveValue() + "\n"); for (int i = 0; i < vehicles; i++) { /* * Display Round Trip: */ Console.WriteLine("Round Trip for Vehicle " + i + "\n"); for (long node = model.Start(i); node < model.End(i); node = model.Next(assignment, node)) { Console.Write(node + " -> "); } Console.WriteLine(model.Start(i) + "\n"); /* * Display individual Section Distances for Verification: */ var source = (int)model.Start(i); while (source < model.End(i)) { var target = (int)model.Next(assignment, source); if (source < dist.MapSize() && target < dist.MapSize()) { Console.WriteLine("From " + source + " travel to " + target + " -> distance = " + dist.Run(source, target)); } else if (source < dist.MapSize()) { Console.WriteLine("From " + source + " travel to 0 -> distance = " + dist.Run(source, 0)); } source = target; } Console.WriteLine("\n"); } } Console.ReadKey(); }
public static void Solve(int vehicles, Distance distances) { /* * 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); /* * A vehicle must not visit more than 7 cities */ //model.AddConstantDimension(1, 7, true, "count"); /* * A vehicle must visit at least 3 cities */ /*model.AddConstantDimension(1, Int32.MaxValue, true, "count"); * var count = model.GetDimensionOrDie("count"); * for (int i = 0; i < vehicles; i++) { * count.CumulVar(model.End(i)).SetMin(3); * }*/ /* * City 3 and 5 must NOT be visited by the same vehicle */ //model.solver().Add(model.VehicleVar(3) != model.VehicleVar(5)); /* * City 3 must be visited before city 5 (not necessarily by the same vehicle) */ /*model.AddConstantDimension(1, Int32.MaxValue, true, "time"); * var time = model.GetDimensionOrDie("time"); * model.solver().Add(time.CumulVar(3) < time.CumulVar(5));*/ /* * City 3 must be visited right after city 5 (not necessarily by the same vhicle) */ /*model.AddConstantDimension(1, Int32.MaxValue, true, "time"); * var time = model.GetDimensionOrDie("time"); * model.solver().Add(time.CumulVar(5) + 1 == time.CumulVar(3));*/ /* * 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 target = model.Next(assignment, source); var from = model.IndexToNode(source); var to = model.IndexToNode(target); total += distances.Run(from, to); Console.WriteLine( $" - From {distances.ToString(@from),-3} travel to {distances.ToString(to),-3} with distance: {distances.Run(@from, to),-3}"); source = target; } Console.WriteLine("Total Distance for Vehicle " + i + ": " + total + "\n"); } } Console.ReadKey(); }
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(); }