public static void Apply(PotvinEncoding solution, PotvinPDShiftMove move, IVRPProblemInstance problemInstance) {
bool newTour = false;
if (move.Tour >= solution.Tours.Count) {
solution.Tours.Add(new Tour());
newTour = true;
}
Tour tour = solution.Tours[move.Tour];
Tour oldTour = solution.Tours.Find(t => t.Stops.Contains(move.City));
oldTour.Stops.Remove(move.City);
if (problemInstance is IPickupAndDeliveryProblemInstance) {
IPickupAndDeliveryProblemInstance pdp = problemInstance as IPickupAndDeliveryProblemInstance;
int location = pdp.GetPickupDeliveryLocation(move.City);
Tour oldTour2 = solution.Tours.Find(t => t.Stops.Contains(location));
oldTour2.Stops.Remove(location);
solution.InsertPair(tour, move.City, location, problemInstance);
} else {
int place = solution.FindBestInsertionPlace(tour, move.City);
tour.Stops.Insert(place, move.City);
}
if (newTour) {
List<int> vehicles = new List<int>();
for (int i = move.Tour; i < problemInstance.Vehicles.Value; i++) {
vehicles.Add(solution.GetVehicleAssignment(i));
}
double bestQuality = double.MaxValue;
int bestVehicle = -1;
int originalVehicle = solution.GetVehicleAssignment(move.Tour);
foreach (int vehicle in vehicles) {
solution.VehicleAssignment[move.Tour] = vehicle;
double quality = problemInstance.EvaluateTour(tour, solution).Quality;
if (quality < bestQuality) {
bestQuality = quality;
bestVehicle = vehicle;
}
}
solution.VehicleAssignment[move.Tour] = originalVehicle;
int index = -1;
for (int i = move.Tour; i < solution.VehicleAssignment.Length; i++) {
if (solution.VehicleAssignment[i] == bestVehicle) {
index = i;
break;
}
}
solution.VehicleAssignment[index] = originalVehicle;
solution.VehicleAssignment[move.Tour] = bestVehicle;
}
solution.Repair();
}
public static void Apply(PotvinEncoding solution, PotvinPDRearrangeMove move, IVRPProblemInstance problemInstance)
{
Tour tour = solution.Tours[move.Tour];
int position = tour.Stops.IndexOf(move.City);
IPickupAndDeliveryProblemInstance pdp = problemInstance as IPickupAndDeliveryProblemInstance;
if (pdp != null)
{
int location = pdp.GetPickupDeliveryLocation(move.City);
Tour tour2 = solution.Tours.Find(t => t.Stops.Contains(location));
int position2 = tour2.Stops.IndexOf(location);
tour.Stops.Remove(move.City);
tour2.Stops.Remove(location);
solution.InsertPair(tour, move.City, location, problemInstance, position, position2);
}
else
{
tour.Stops.Remove(move.City);
int place = solution.FindBestInsertionPlace(tour, move.City, position);
tour.Stops.Insert(place, move.City);
}
solution.Repair();
}
public static void Apply(PotvinEncoding solution, PotvinPDExchangeMove move, IVRPProblemInstance problemInstance) {
if (move.Tour >= solution.Tours.Count)
solution.Tours.Add(new Tour());
Tour tour = solution.Tours[move.Tour];
Tour oldTour = solution.Tours.Find(t => t.Stops.Contains(move.City));
oldTour.Stops.Remove(move.City);
if (problemInstance is IPickupAndDeliveryProblemInstance) {
IPickupAndDeliveryProblemInstance pdp = problemInstance as IPickupAndDeliveryProblemInstance;
int location = pdp.GetPickupDeliveryLocation(move.City);
Tour oldTour2 = solution.Tours.Find(t => t.Stops.Contains(location));
oldTour2.Stops.Remove(location);
location = pdp.GetPickupDeliveryLocation(move.Replaced);
oldTour2 = solution.Tours.Find(t => t.Stops.Contains(location));
oldTour2.Stops.Remove(location);
tour.Stops.Remove(move.Replaced);
solution.InsertPair(tour, move.City, pdp.GetPickupDeliveryLocation(move.City), problemInstance);
solution.InsertPair(oldTour, move.Replaced, pdp.GetPickupDeliveryLocation(move.Replaced), problemInstance);
} else {
tour.Stops.Remove(move.Replaced);
int place = solution.FindBestInsertionPlace(tour, move.City);
tour.Stops.Insert(place, move.City);
place = solution.FindBestInsertionPlace(oldTour, move.Replaced);
oldTour.Stops.Insert(place, move.Replaced);
}
solution.Repair();
}
public static void Apply(PotvinEncoding solution, PotvinPDExchangeMove move, IVRPProblemInstance problemInstance)
{
if (move.Tour >= solution.Tours.Count)
{
solution.Tours.Add(new Tour());
}
Tour tour = solution.Tours[move.Tour];
Tour oldTour = solution.Tours.Find(t => t.Stops.Contains(move.City));
oldTour.Stops.Remove(move.City);
if (problemInstance is IPickupAndDeliveryProblemInstance)
{
IPickupAndDeliveryProblemInstance pdp = problemInstance as IPickupAndDeliveryProblemInstance;
int location = pdp.GetPickupDeliveryLocation(move.City);
Tour oldTour2 = solution.Tours.Find(t => t.Stops.Contains(location));
oldTour2.Stops.Remove(location);
location = pdp.GetPickupDeliveryLocation(move.Replaced);
oldTour2 = solution.Tours.Find(t => t.Stops.Contains(location));
oldTour2.Stops.Remove(location);
tour.Stops.Remove(move.Replaced);
solution.InsertPair(tour, move.City, pdp.GetPickupDeliveryLocation(move.City), problemInstance);
solution.InsertPair(oldTour, move.Replaced, pdp.GetPickupDeliveryLocation(move.Replaced), problemInstance);
}
else
{
tour.Stops.Remove(move.Replaced);
int place = solution.FindBestInsertionPlace(tour, move.City);
tour.Stops.Insert(place, move.City);
place = solution.FindBestInsertionPlace(oldTour, move.Replaced);
oldTour.Stops.Insert(place, move.Replaced);
}
solution.Repair();
}
protected override int Improve(PotvinEncoding solution) {
int evaluatedSolutions = 0;
var rand = RandomParameter.ActualValue;
var instance = ProblemInstance;
int sampleSize = SampleSizeParameter.Value.Value;
int attempts = ImprovementAttemptsParameter.Value.Value;
int customers = instance.Cities.Value;
// store city-to-tour assignment and position of the city within the tour
var tours = new Dictionary<int, Tour>();
var position = new Dictionary<int, int>();
foreach (Tour tour in solution.Tours) {
for (int stop = 0; stop < tour.Stops.Count; stop++) {
int city = tour.Stops[stop];
tours[city] = tour;
position[city] = stop;
}
}
for (int attempt = 0; attempt < attempts; attempt++) {
for (int sample = 0; sample < sampleSize; sample++) {
int chosenCust = 1 + rand.Next(customers);
var custTour = tours[chosenCust];
double beforeQuality = instance.EvaluateTour(custTour, solution).Quality;
evaluatedSolutions++;
custTour.Stops.RemoveAt(position[chosenCust]);
int place = solution.FindBestInsertionPlace(custTour, chosenCust);
evaluatedSolutions += custTour.Stops.Count;
custTour.Stops.Insert(place, chosenCust);
if (place != position[chosenCust]) {
double afterQuality = instance.EvaluateTour(custTour, solution).Quality;
if (afterQuality > beforeQuality) {
// revert move
custTour.Stops.RemoveAt(place);
custTour.Stops.Insert(position[chosenCust], chosenCust);
} else {
// accept move and update positions of the cities within the tour
for (int stop = 0; stop < custTour.Stops.Count; stop++) {
int city = custTour.Stops[stop];
position[city] = stop;
}
break;
}
}
}
}
return evaluatedSolutions;
}
public static void Apply(PotvinEncoding solution, PotvinCustomerRelocationMove move, IVRPProblemInstance problemInstance) {
if (move.Tour >= solution.Tours.Count)
solution.Tours.Add(new Tour());
Tour tour = solution.Tours[move.Tour];
Tour oldTour = solution.Tours.Find(t => t.Stops.Contains(move.City));
oldTour.Stops.Remove(move.City);
/*if (oldTour.Stops.Count == 0)
solution.Tours.Remove(oldTour);*/
int place = solution.FindBestInsertionPlace(tour, move.City);
tour.Stops.Insert(place, move.City);
solution.Repair();
}
public static void Apply(PotvinEncoding solution, PotvinCustomerRelocationMove move, IVRPProblemInstance problemInstance)
{
if (move.Tour >= solution.Tours.Count)
{
solution.Tours.Add(new Tour());
}
Tour tour = solution.Tours[move.Tour];
Tour oldTour = solution.Tours.Find(t => t.Stops.Contains(move.City));
oldTour.Stops.Remove(move.City);
/*if (oldTour.Stops.Count == 0)
* solution.Tours.Remove(oldTour);*/
int place = solution.FindBestInsertionPlace(tour, move.City);
tour.Stops.Insert(place, move.City);
solution.Repair();
}
public static void Apply(PotvinEncoding solution, PotvinPDRearrangeMove move, IVRPProblemInstance problemInstance) {
Tour tour = solution.Tours[move.Tour];
int position = tour.Stops.IndexOf(move.City);
IPickupAndDeliveryProblemInstance pdp = problemInstance as IPickupAndDeliveryProblemInstance;
if (pdp != null) {
int location = pdp.GetPickupDeliveryLocation(move.City);
Tour tour2 = solution.Tours.Find(t => t.Stops.Contains(location));
int position2 = tour2.Stops.IndexOf(location);
tour.Stops.Remove(move.City);
tour2.Stops.Remove(location);
solution.InsertPair(tour, move.City, location, problemInstance, position, position2);
} else {
tour.Stops.Remove(move.City);
int place = solution.FindBestInsertionPlace(tour, move.City, position);
tour.Stops.Insert(place, move.City);
}
solution.Repair();
}
public static PotvinEncoding CreateSolution(IVRPProblemInstance instance, IRandom random, bool adhereTimeWindows) {
PotvinEncoding result = new PotvinEncoding(instance);
IPickupAndDeliveryProblemInstance pdp = instance as IPickupAndDeliveryProblemInstance;
List<int> customers = new List<int>();
for (int i = 1; i <= instance.Cities.Value; i++)
if (pdp == null || pdp.GetDemand(i) >= 0)
customers.Add(i);
customers.Sort((city1, city2) => {
double angle1 = CalculateAngleToDepot(instance, city1);
double angle2 = CalculateAngleToDepot(instance, city2);
return angle1.CompareTo(angle2);
});
Tour currentTour = new Tour();
result.Tours.Add(currentTour);
int j = random.Next(customers.Count);
for (int i = 0; i < customers.Count; i++) {
int index = (i + j) % customers.Count;
int stopIdx = 0;
if (currentTour.Stops.Count > 0)
stopIdx = result.FindBestInsertionPlace(currentTour, customers[index]);
currentTour.Stops.Insert(stopIdx, customers[index]);
if (pdp != null) {
stopIdx = result.FindBestInsertionPlace(currentTour, pdp.GetPickupDeliveryLocation(customers[index]));
currentTour.Stops.Insert(stopIdx, pdp.GetPickupDeliveryLocation(customers[index]));
}
CVRPEvaluation evaluation = instance.EvaluateTour(currentTour, result) as CVRPEvaluation;
if (result.Tours.Count < instance.Vehicles.Value &&
((adhereTimeWindows && !instance.Feasible(evaluation)) || ((!adhereTimeWindows) && evaluation.Overload > double.Epsilon))) {
currentTour.Stops.Remove(customers[index]);
if (pdp != null)
currentTour.Stops.Remove(pdp.GetPickupDeliveryLocation(customers[index]));
if (currentTour.Stops.Count == 0)
result.Tours.Remove(currentTour);
currentTour = new Tour();
result.Tours.Add(currentTour);
currentTour.Stops.Add(customers[index]);
if (pdp != null) {
currentTour.Stops.Add(pdp.GetPickupDeliveryLocation(customers[index]));
}
}
}
if (currentTour.Stops.Count == 0)
result.Tours.Remove(currentTour);
return result;
}
public static PotvinEncoding CreateSolution(IVRPProblemInstance instance, IRandom random, bool adhereTimeWindows)
{
PotvinEncoding result = new PotvinEncoding(instance);
IPickupAndDeliveryProblemInstance pdp = instance as IPickupAndDeliveryProblemInstance;
List <int> customers = new List <int>();
for (int i = 1; i <= instance.Cities.Value; i++)
{
if (pdp == null || pdp.GetDemand(i) >= 0)
{
customers.Add(i);
}
}
customers.Sort((city1, city2) => {
double angle1 = CalculateAngleToDepot(instance, city1);
double angle2 = CalculateAngleToDepot(instance, city2);
return(angle1.CompareTo(angle2));
});
Tour currentTour = new Tour();
result.Tours.Add(currentTour);
int j = random.Next(customers.Count);
for (int i = 0; i < customers.Count; i++)
{
int index = (i + j) % customers.Count;
int stopIdx = 0;
if (currentTour.Stops.Count > 0)
{
stopIdx = result.FindBestInsertionPlace(currentTour, customers[index]);
}
currentTour.Stops.Insert(stopIdx, customers[index]);
if (pdp != null)
{
stopIdx = result.FindBestInsertionPlace(currentTour, pdp.GetPickupDeliveryLocation(customers[index]));
currentTour.Stops.Insert(stopIdx, pdp.GetPickupDeliveryLocation(customers[index]));
}
CVRPEvaluation evaluation = instance.EvaluateTour(currentTour, result) as CVRPEvaluation;
if (result.Tours.Count < instance.Vehicles.Value &&
((adhereTimeWindows && !instance.Feasible(evaluation)) || ((!adhereTimeWindows) && evaluation.Overload > double.Epsilon)))
{
currentTour.Stops.Remove(customers[index]);
if (pdp != null)
{
currentTour.Stops.Remove(pdp.GetPickupDeliveryLocation(customers[index]));
}
if (currentTour.Stops.Count == 0)
{
result.Tours.Remove(currentTour);
}
currentTour = new Tour();
result.Tours.Add(currentTour);
currentTour.Stops.Add(customers[index]);
if (pdp != null)
{
currentTour.Stops.Add(pdp.GetPickupDeliveryLocation(customers[index]));
}
}
}
if (currentTour.Stops.Count == 0)
{
result.Tours.Remove(currentTour);
}
return(result);
}
public static void Apply(PotvinEncoding solution, PotvinPDShiftMove move, IVRPProblemInstance problemInstance)
{
bool newTour = false;
if (move.Tour >= solution.Tours.Count)
{
solution.Tours.Add(new Tour());
newTour = true;
}
Tour tour = solution.Tours[move.Tour];
Tour oldTour = solution.Tours.Find(t => t.Stops.Contains(move.City));
oldTour.Stops.Remove(move.City);
if (problemInstance is IPickupAndDeliveryProblemInstance)
{
IPickupAndDeliveryProblemInstance pdp = problemInstance as IPickupAndDeliveryProblemInstance;
int location = pdp.GetPickupDeliveryLocation(move.City);
Tour oldTour2 = solution.Tours.Find(t => t.Stops.Contains(location));
oldTour2.Stops.Remove(location);
solution.InsertPair(tour, move.City, location, problemInstance);
}
else
{
int place = solution.FindBestInsertionPlace(tour, move.City);
tour.Stops.Insert(place, move.City);
}
if (newTour)
{
List <int> vehicles = new List <int>();
for (int i = move.Tour; i < problemInstance.Vehicles.Value; i++)
{
vehicles.Add(solution.GetVehicleAssignment(i));
}
double bestQuality = double.MaxValue;
int bestVehicle = -1;
int originalVehicle = solution.GetVehicleAssignment(move.Tour);
foreach (int vehicle in vehicles)
{
solution.VehicleAssignment[move.Tour] = vehicle;
double quality = problemInstance.EvaluateTour(tour, solution).Quality;
if (quality < bestQuality)
{
bestQuality = quality;
bestVehicle = vehicle;
}
}
solution.VehicleAssignment[move.Tour] = originalVehicle;
int index = -1;
for (int i = move.Tour; i < solution.VehicleAssignment.Length; i++)
{
if (solution.VehicleAssignment[i] == bestVehicle)
{
index = i;
break;
}
}
solution.VehicleAssignment[index] = originalVehicle;
solution.VehicleAssignment[move.Tour] = bestVehicle;
}
solution.Repair();
}
