public void InsertPair(Tour tour, int source, int target, IVRPProblemInstance problemInstance, int positionToAvoid = -1, int positionToAvoid2 = -1) { int stops = tour.Stops.Count; VRPEvaluation eval = problemInstance.EvaluateTour(tour, this); double minCosts = double.MaxValue; int sourceLocation = -1; int targetLocation = -1; for (int i = 0; i <= stops; i++) { tour.Stops.Insert(i, source); VRPEvaluation tourEval = problemInstance.EvaluateTour(tour, this); double sourceCosts = tourEval.Quality - eval.Quality; for (int j = i + 1; j <= stops + 1; j++) { if (positionToAvoid != i || positionToAvoid2 != j || stops == 0) { bool feasible; double targetCosts = problemInstance.GetInsertionCosts(tourEval, this, target, 0, j, out feasible); double costs = sourceCosts + targetCosts; if (costs < minCosts) { minCosts = costs; sourceLocation = i; targetLocation = j; } } } tour.Stops.Remove(source); } tour.Stops.Insert(sourceLocation, source); tour.Stops.Insert(targetLocation, target); }
public static PotvinEncoding CreateSolution(IVRPProblemInstance problemInstance, IRandom random, double alphaValue = 0.7, double betaValue = 0.1, double gammaValue = 0.2, double alphaVariance = 0.5, double betaVariance = 0.07, double gammaVariance = 0.14) { PotvinEncoding result = new PotvinEncoding(problemInstance); IPickupAndDeliveryProblemInstance pdp = problemInstance as IPickupAndDeliveryProblemInstance; IMultiDepotProblemInstance mdp = problemInstance as IMultiDepotProblemInstance; double alpha, beta, gamma; alpha = N(alphaValue, Math.Sqrt(alphaVariance), random); beta = N(betaValue, Math.Sqrt(betaVariance), random); gamma = N(gammaValue, Math.Sqrt(gammaVariance), random); List<int> unroutedCustomers = new List<int>(); for (int i = 1; i <= problemInstance.Cities.Value; i++) { if (pdp == null || (problemInstance.GetDemand(i) >= 0)) unroutedCustomers.Add(i); } List<int> depots = new List<int>(); if (mdp != null) { for (int i = 0; i < mdp.Depots.Value; i++) { depots.Add(i); } } else { depots.Add(0); } Dictionary<int, List<int>> vehicles = new Dictionary<int, List<int>>(); foreach (int depot in depots) { vehicles[depot] = new List<int>(); int vehicleCount = problemInstance.Vehicles.Value; if (mdp != null) { for (int vehicle = 0; vehicle < mdp.VehicleDepotAssignment.Length; vehicle++) { if (mdp.VehicleDepotAssignment[vehicle] == depot) { vehicles[depot].Add(vehicle); } } } else { for (int vehicle = 0; vehicle < vehicleCount; vehicle++) { vehicles[depot].Add(vehicle); } } } RemoveUnusedDepots(depots, vehicles); Dictionary<int, int> depotAssignment = new Dictionary<int, int>(); unroutedCustomers = SortCustomers( problemInstance, unroutedCustomers, depots, depotAssignment, alpha, beta, gamma); ///////// Tour tour = new Tour(); result.Tours.Add(tour); int currentCustomer = unroutedCustomers[0]; unroutedCustomers.RemoveAt(0); int currentDepot = depotAssignment[currentCustomer]; int currentVehicle = vehicles[currentDepot][0]; vehicles[currentDepot].RemoveAt(0); if (RemoveUnusedDepots(depots, vehicles)) { unroutedCustomers = SortCustomers( problemInstance, unroutedCustomers, depots, depotAssignment, alpha, beta, gamma); } result.VehicleAssignment[result.Tours.Count - 1] = currentVehicle; tour.Stops.Add(currentCustomer); if (pdp != null) { tour.Stops.Add(pdp.GetPickupDeliveryLocation(currentCustomer)); } //////// while (unroutedCustomers.Count > 0) { double minimumCost = double.MaxValue; int customer = -1; int indexOfMinimumCost = -1; int indexOfMinimumCost2 = -1; foreach (int unrouted in unroutedCustomers) { VRPEvaluation eval = problemInstance.EvaluateTour(tour, result); double originalCosts = eval.Quality; for (int i = 0; i <= tour.Stops.Count; i++) { tour.Stops.Insert(i, unrouted); eval = problemInstance.EvaluateTour(tour, result); double tourCost = eval.Quality - originalCosts; if (pdp != null) { for (int j = i + 1; j <= tour.Stops.Count; j++) { bool feasible; double cost = tourCost + problemInstance.GetInsertionCosts(eval, result, pdp.GetPickupDeliveryLocation(unrouted), 0, j, out feasible); if (cost < minimumCost && feasible) { customer = unrouted; minimumCost = cost; indexOfMinimumCost = i; indexOfMinimumCost2 = j; } } } else { double cost = tourCost; bool feasible = problemInstance.Feasible(eval); if (cost < minimumCost && feasible) { customer = unrouted; minimumCost = cost; indexOfMinimumCost = i; } } tour.Stops.RemoveAt(i); } } if (indexOfMinimumCost == -1 && vehicles.Count == 0) { indexOfMinimumCost = tour.Stops.Count; indexOfMinimumCost2 = tour.Stops.Count + 1; customer = unroutedCustomers[0]; } // insert customer if found if (indexOfMinimumCost != -1) { tour.Stops.Insert(indexOfMinimumCost, customer); if (pdp != null) { tour.Stops.Insert(indexOfMinimumCost2, pdp.GetPickupDeliveryLocation(customer)); } unroutedCustomers.Remove(customer); } else { // no feasible customer found tour = new Tour(); result.Tours.Add(tour); currentCustomer = unroutedCustomers[0]; unroutedCustomers.RemoveAt(0); currentDepot = depotAssignment[currentCustomer]; currentVehicle = vehicles[currentDepot][0]; vehicles[currentDepot].RemoveAt(0); if (RemoveUnusedDepots(depots, vehicles)) { unroutedCustomers = SortCustomers( problemInstance, unroutedCustomers, depots, depotAssignment, alpha, beta, gamma); } result.VehicleAssignment[result.Tours.Count - 1] = currentVehicle; tour.Stops.Add(currentCustomer); if (pdp != null) { tour.Stops.Add(pdp.GetPickupDeliveryLocation(currentCustomer)); } } } if (mdp != null) { List<int> availableVehicles = new List<int>(); for (int i = 0; i < mdp.Vehicles.Value; i++) availableVehicles.Add(i); for (int i = 0; i < result.VehicleAssignment.Length; i++) { if (result.VehicleAssignment[i] != -1) availableVehicles.Remove(result.VehicleAssignment[i]); } for (int i = 0; i < result.VehicleAssignment.Length; i++) { if (result.VehicleAssignment[i] == -1) { result.VehicleAssignment[i] = availableVehicles[0]; availableVehicles.RemoveAt(0); } } } return result; }
public static PotvinEncoding CreateSolution(IVRPProblemInstance problemInstance, IRandom random, double alphaValue = 0.7, double betaValue = 0.1, double gammaValue = 0.2, double alphaVariance = 0.5, double betaVariance = 0.07, double gammaVariance = 0.14) { PotvinEncoding result = new PotvinEncoding(problemInstance); IPickupAndDeliveryProblemInstance pdp = problemInstance as IPickupAndDeliveryProblemInstance; IMultiDepotProblemInstance mdp = problemInstance as IMultiDepotProblemInstance; double alpha, beta, gamma; alpha = N(alphaValue, Math.Sqrt(alphaVariance), random); beta = N(betaValue, Math.Sqrt(betaVariance), random); gamma = N(gammaValue, Math.Sqrt(gammaVariance), random); List <int> unroutedCustomers = new List <int>(); for (int i = 1; i <= problemInstance.Cities.Value; i++) { if (pdp == null || (problemInstance.GetDemand(i) >= 0)) { unroutedCustomers.Add(i); } } List <int> depots = new List <int>(); if (mdp != null) { for (int i = 0; i < mdp.Depots.Value; i++) { depots.Add(i); } } else { depots.Add(0); } Dictionary <int, List <int> > vehicles = new Dictionary <int, List <int> >(); foreach (int depot in depots) { vehicles[depot] = new List <int>(); int vehicleCount = problemInstance.Vehicles.Value; if (mdp != null) { for (int vehicle = 0; vehicle < mdp.VehicleDepotAssignment.Length; vehicle++) { if (mdp.VehicleDepotAssignment[vehicle] == depot) { vehicles[depot].Add(vehicle); } } } else { for (int vehicle = 0; vehicle < vehicleCount; vehicle++) { vehicles[depot].Add(vehicle); } } } RemoveUnusedDepots(depots, vehicles); Dictionary <int, int> depotAssignment = new Dictionary <int, int>(); unroutedCustomers = SortCustomers( problemInstance, unroutedCustomers, depots, depotAssignment, alpha, beta, gamma); ///////// Tour tour = new Tour(); result.Tours.Add(tour); int currentCustomer = unroutedCustomers[0]; unroutedCustomers.RemoveAt(0); int currentDepot = depotAssignment[currentCustomer]; int currentVehicle = vehicles[currentDepot][0]; vehicles[currentDepot].RemoveAt(0); if (RemoveUnusedDepots(depots, vehicles)) { unroutedCustomers = SortCustomers( problemInstance, unroutedCustomers, depots, depotAssignment, alpha, beta, gamma); } result.VehicleAssignment[result.Tours.Count - 1] = currentVehicle; tour.Stops.Add(currentCustomer); if (pdp != null) { tour.Stops.Add(pdp.GetPickupDeliveryLocation(currentCustomer)); } //////// while (unroutedCustomers.Count > 0) { double minimumCost = double.MaxValue; int customer = -1; int indexOfMinimumCost = -1; int indexOfMinimumCost2 = -1; foreach (int unrouted in unroutedCustomers) { VRPEvaluation eval = problemInstance.EvaluateTour(tour, result); double originalCosts = eval.Quality; for (int i = 0; i <= tour.Stops.Count; i++) { tour.Stops.Insert(i, unrouted); eval = problemInstance.EvaluateTour(tour, result); double tourCost = eval.Quality - originalCosts; if (pdp != null) { for (int j = i + 1; j <= tour.Stops.Count; j++) { bool feasible; double cost = tourCost + problemInstance.GetInsertionCosts(eval, result, pdp.GetPickupDeliveryLocation(unrouted), 0, j, out feasible); if (cost < minimumCost && feasible) { customer = unrouted; minimumCost = cost; indexOfMinimumCost = i; indexOfMinimumCost2 = j; } } } else { double cost = tourCost; bool feasible = problemInstance.Feasible(eval); if (cost < minimumCost && feasible) { customer = unrouted; minimumCost = cost; indexOfMinimumCost = i; } } tour.Stops.RemoveAt(i); } } if (indexOfMinimumCost == -1 && vehicles.Count == 0) { indexOfMinimumCost = tour.Stops.Count; indexOfMinimumCost2 = tour.Stops.Count + 1; customer = unroutedCustomers[0]; } // insert customer if found if (indexOfMinimumCost != -1) { tour.Stops.Insert(indexOfMinimumCost, customer); if (pdp != null) { tour.Stops.Insert(indexOfMinimumCost2, pdp.GetPickupDeliveryLocation(customer)); } unroutedCustomers.Remove(customer); } else // no feasible customer found { tour = new Tour(); result.Tours.Add(tour); currentCustomer = unroutedCustomers[0]; unroutedCustomers.RemoveAt(0); currentDepot = depotAssignment[currentCustomer]; currentVehicle = vehicles[currentDepot][0]; vehicles[currentDepot].RemoveAt(0); if (RemoveUnusedDepots(depots, vehicles)) { unroutedCustomers = SortCustomers( problemInstance, unroutedCustomers, depots, depotAssignment, alpha, beta, gamma); } result.VehicleAssignment[result.Tours.Count - 1] = currentVehicle; tour.Stops.Add(currentCustomer); if (pdp != null) { tour.Stops.Add(pdp.GetPickupDeliveryLocation(currentCustomer)); } } } if (mdp != null) { List <int> availableVehicles = new List <int>(); for (int i = 0; i < mdp.Vehicles.Value; i++) { availableVehicles.Add(i); } for (int i = 0; i < result.VehicleAssignment.Length; i++) { if (result.VehicleAssignment[i] != -1) { availableVehicles.Remove(result.VehicleAssignment[i]); } } for (int i = 0; i < result.VehicleAssignment.Length; i++) { if (result.VehicleAssignment[i] == -1) { result.VehicleAssignment[i] = availableVehicles[0]; availableVehicles.RemoveAt(0); } } } return(result); }