public static PotvinPDRearrangeMove Apply(PotvinEncoding individual, IVRPProblemInstance problemInstance, IRandom rand)
{
List <int> cities = new List <int>();
IPickupAndDeliveryProblemInstance pdp = problemInstance as IPickupAndDeliveryProblemInstance;
for (int i = 1; i <= individual.Cities; i++)
{
if (pdp == null || pdp.GetDemand(i) >= 0)
{
cities.Add(i);
}
}
if (cities.Count > 0)
{
int city = cities[rand.Next(cities.Count)];
int tour = individual.Tours.FindIndex(t => t.Stops.Contains(city));
return(new PotvinPDRearrangeMove(city, tour, individual));
}
else
{
return(null);
}
}
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();
}
protected override PotvinPDShiftMove[] GenerateMoves(PotvinEncoding individual, IVRPProblemInstance problemInstance)
{
List <PotvinPDShiftMove> result = new List <PotvinPDShiftMove>();
IPickupAndDeliveryProblemInstance pdp = problemInstance as IPickupAndDeliveryProblemInstance;
int max = individual.Tours.Count;
if (individual.Tours.Count >= problemInstance.Vehicles.Value)
{
max = max - 1;
}
for (int i = 0; i < individual.Tours.Count; i++)
{
for (int j = 0; j < individual.Tours[i].Stops.Count; j++)
{
for (int k = 0; k <= max; k++)
{
if (k != i)
{
int city = individual.Tours[i].Stops[j];
if (pdp == null || pdp.GetDemand(city) >= 0)
{
PotvinPDShiftMove move = new PotvinPDShiftMove(
city, i, k, individual);
result.Add(move);
}
}
}
}
}
return(result.ToArray());
}
public static PotvinPDExchangeMove Apply(PotvinEncoding individual, IVRPProblemInstance problemInstance, IRandom rand)
{
List <int> cities = new List <int>();
IPickupAndDeliveryProblemInstance pdp = problemInstance as IPickupAndDeliveryProblemInstance;
for (int i = 1; i <= individual.Cities; i++)
{
if (pdp == null || pdp.GetDemand(i) >= 0)
{
cities.Add(i);
}
}
if (cities.Count > 1 && individual.Tours.Count > 1)
{
PotvinPDExchangeMove move = null;
while (cities.Count > 1 && move == null)
{
int city = cities[rand.Next(cities.Count)];
Tour oldTour = individual.Tours.Find(t => t.Stops.Contains(city));
int oldTourIndex = individual.Tours.IndexOf(oldTour);
int max = individual.Tours.Count - 1;
int newTourIndex = rand.Next(max);
if (newTourIndex >= oldTourIndex)
{
newTourIndex++;
}
Tour newTour = individual.Tours[newTourIndex];
List <int> tourCities = new List <int>();
foreach (int stop in newTour.Stops)
{
if (pdp == null ||
(pdp.GetDemand(stop) >= 0 &&
pdp.GetPickupDeliveryLocation(stop) != pdp.GetPickupDeliveryLocation(city) &&
pdp.GetPickupDeliveryLocation(stop) != city &&
pdp.GetPickupDeliveryLocation(city) != stop))
{
tourCities.Add(stop);
}
}
if (tourCities.Count > 0)
{
int replaced = tourCities[rand.Next(tourCities.Count)];
move = new PotvinPDExchangeMove(city, oldTourIndex, newTourIndex, replaced, individual);
}
}
return(move);
}
else
{
return(null);
}
}
public override IOperation Apply()
{
IPickupAndDeliveryProblemInstance pdp = ProblemInstanceParameter.ActualValue as IPickupAndDeliveryProblemInstance;
ResultCollection results = ResultsParameter.ActualValue;
ItemArray <DoubleValue> qualities = QualityParameter.ActualValue;
ItemArray <IntValue> pickupViolations = PickupViolationsParameter.ActualValue;
double sigma = SigmaParameter.Value.Value;
double phi = PhiParameter.Value.Value;
double minPenalty = MinPenaltyFactorParameter.Value.Value;
double maxPenalty = MaxPenaltyFactorParameter.Value.Value;
for (int j = 0; j < qualities.Length; j++)
{
qualities[j].Value -= pickupViolations[j].Value * pdp.PickupViolationPenalty.Value;
}
int validCount = 0;
for (int j = 0; j < qualities.Length; j++)
{
if (pickupViolations[j].Value == 0)
{
validCount++;
}
}
double factor = 1.0 - ((double)validCount / (double)qualities.Length);
double min = pdp.PickupViolationPenalty.Value / (1 + sigma);
double max = pdp.PickupViolationPenalty.Value * (1 + phi);
pdp.CurrentPickupViolationPenalty = new DoubleValue(min + (max - min) * factor);
if (pdp.CurrentPickupViolationPenalty.Value < minPenalty)
{
pdp.CurrentPickupViolationPenalty.Value = minPenalty;
}
if (pdp.CurrentPickupViolationPenalty.Value > maxPenalty)
{
pdp.CurrentPickupViolationPenalty.Value = maxPenalty;
}
for (int j = 0; j < qualities.Length; j++)
{
qualities[j].Value += pickupViolations[j].Value * pdp.CurrentPickupViolationPenalty.Value;
}
if (!results.ContainsKey("Current Pickup Violation Penalty"))
{
results.Add(new Result("Current Pickup Violation Penalty", new DoubleValue(pdp.CurrentPickupViolationPenalty.Value)));
}
else
{
(results["Current Pickup Violation Penalty"].Value as DoubleValue).Value = pdp.CurrentPickupViolationPenalty.Value;
}
return(base.Apply());
}
protected override void Manipulate(IRandom random, PotvinEncoding individual)
{
bool allowInfeasible = AllowInfeasibleSolutions.Value.Value;
IPickupAndDeliveryProblemInstance pdp = ProblemInstance as IPickupAndDeliveryProblemInstance;
if (pdp != null)
{
ApplyManipulation(random, individual, pdp, allowInfeasible);
}
}
protected override PotvinPDExchangeMove[] GenerateMoves(PotvinEncoding individual, IVRPProblemInstance problemInstance)
{
List <PotvinPDExchangeMove> result = new List <PotvinPDExchangeMove>();
IPickupAndDeliveryProblemInstance pdp = problemInstance as IPickupAndDeliveryProblemInstance;
int max = individual.Tours.Count;
if (individual.Tours.Count < problemInstance.Vehicles.Value)
{
max = max - 1;
}
for (int i = 0; i < individual.Tours.Count; i++)
{
for (int j = 0; j < individual.Tours[i].Stops.Count; j++)
{
for (int k = 0; k <= max; k++)
{
if (k != i)
{
int city1 = individual.Tours[i].Stops[j];
if (pdp == null || pdp.GetDemand(city1) >= 0)
{
for (int l = 0; l < individual.Tours[k].Stops.Count; l++)
{
int city2 = individual.Tours[k].Stops[l];
if (pdp == null || pdp.GetDemand(city2) >= 0)
{
bool valid = pdp == null ||
(pdp.GetPickupDeliveryLocation(city2) != pdp.GetPickupDeliveryLocation(city1) &&
pdp.GetPickupDeliveryLocation(city2) != city1 &&
pdp.GetPickupDeliveryLocation(city1) != city2);
if (valid)
{
PotvinPDExchangeMove move = new PotvinPDExchangeMove(
city1, i, k, city2, individual);
result.Add(move);
}
}
}
}
}
}
}
}
return(result.ToArray());
}
protected override void Manipulate(IRandom random, PotvinEncoding individual)
{
bool allowInfeasible = AllowInfeasibleSolutions.Value.Value;
IPickupAndDeliveryProblemInstance pdp = ProblemInstance as IPickupAndDeliveryProblemInstance;
if (pdp != null)
{
PotvinEncoding result = ApplyManipulation(random, individual, pdp, allowInfeasible);
if (result != null)
{
VRPToursParameter.ActualValue = result;
}
}
}
protected override PotvinPDRearrangeMove[] GenerateMoves(PotvinEncoding individual, IVRPProblemInstance problemInstance)
{
List <PotvinPDRearrangeMove> result = new List <PotvinPDRearrangeMove>();
IPickupAndDeliveryProblemInstance pdp = problemInstance as IPickupAndDeliveryProblemInstance;
for (int i = 1; i <= problemInstance.Cities.Value; i++)
{
if (pdp == null || pdp.GetDemand(i) >= 0)
{
int tour = individual.Tours.FindIndex(t => t.Stops.Contains(i));
result.Add(new PotvinPDRearrangeMove(i, tour, individual));
}
}
return(result.ToArray());
}
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 PotvinPDShiftMove Apply(PotvinEncoding individual, IVRPProblemInstance problemInstance, IRandom rand)
{
List <int> cities = new List <int>();
IPickupAndDeliveryProblemInstance pdp = problemInstance as IPickupAndDeliveryProblemInstance;
for (int i = 1; i <= individual.Cities; i++)
{
if (pdp == null || pdp.GetDemand(i) >= 0)
{
cities.Add(i);
}
}
if (cities.Count >= 1)
{
int city = cities[rand.Next(cities.Count)];
Tour oldTour = individual.Tours.Find(t => t.Stops.Contains(city));
int oldTourIndex = individual.Tours.IndexOf(oldTour);
int max = individual.Tours.Count;
if (individual.Tours.Count >= problemInstance.Vehicles.Value)
{
max = max - 1;
}
int newTourIndex = rand.Next(max);
if (newTourIndex >= oldTourIndex)
{
newTourIndex++;
}
return(new PotvinPDShiftMove(city, oldTourIndex, newTourIndex, individual));
}
else
{
return(null);
}
}
public static void ApplyManipulation(IRandom random, PotvinEncoding individual, IPickupAndDeliveryProblemInstance pdp, bool allowInfeasible) {
int selectedIndex = SelectRandomTourBiasedByLength(random, individual, pdp);
if (selectedIndex >= 0) {
Tour route1 =
individual.Tours[selectedIndex];
int count = route1.Stops.Count;
if (count > 0) {
int i = random.Next(0, count);
int city = route1.Stops[i];
if (!PairwiseMove(individual, pdp, city, allowInfeasible))
i++;
count = route1.Stops.Count;
}
}
}
public override IOperation Apply()
{
ItemList <IItem> tabuList = TabuListParameter.ActualValue;
double moveQuality = MoveQualityParameter.ActualValue.Value;
bool useAspiration = UseAspirationCriterion.Value;
bool isTabu = false;
PotvinPDRearrangeMove move = PDRearrangeMoveParameter.ActualValue;
foreach (IItem tabuMove in tabuList)
{
PotvinPDRelocateMoveAttribute attribute = tabuMove as PotvinPDRelocateMoveAttribute;
if (attribute != null)
{
double distance = 0;
if (MoveDistanceParameter.ActualValue != null)
{
distance = MoveDistanceParameter.ActualValue.Value;
}
double overload = 0;
if (MoveOverloadParameter.ActualValue != null)
{
overload = MoveOverloadParameter.ActualValue.Value;
}
double tardiness = 0;
if (MoveTardinessParameter.ActualValue != null)
{
tardiness = MoveTardinessParameter.ActualValue.Value;
}
IVRPProblemInstance instance = ProblemInstanceParameter.ActualValue;
double quality = attribute.Distance * instance.DistanceFactor.Value;
IHomogenousCapacitatedProblemInstance cvrp = instance as IHomogenousCapacitatedProblemInstance;
if (cvrp != null)
{
quality += attribute.Overload * cvrp.OverloadPenalty.Value;
}
ITimeWindowedProblemInstance vrptw = instance as ITimeWindowedProblemInstance;
if (vrptw != null)
{
quality += attribute.Tardiness * vrptw.TardinessPenalty.Value;
}
IPickupAndDeliveryProblemInstance pdp = instance as IPickupAndDeliveryProblemInstance;
if (pdp != null)
{
quality += attribute.PickupViolations * pdp.PickupViolationPenalty.Value;
}
if (!useAspiration || moveQuality >= quality)
{
if (attribute.City == move.City && attribute.Tour == move.Tour)
{
isTabu = true;
break;
}
if (attribute.Distance == distance && attribute.Overload == overload && attribute.Tardiness == tardiness)
{
isTabu = true;
break;
}
}
}
}
MoveTabuParameter.ActualValue = new BoolValue(isTabu);
return(base.Apply());
}
public static bool PairwiseMove(PotvinEncoding individual, IVRPProblemInstance instance, int city, bool allowInfeasible)
{
bool success;
IPickupAndDeliveryProblemInstance pdp = instance as IPickupAndDeliveryProblemInstance;
if (pdp != null)
{
Tour route1 = individual.Tours.Find(t => t.Stops.Contains(city));
int i = route1.Stops.IndexOf(city);
int dest = pdp.GetPickupDeliveryLocation(city);
Tour destRoute = individual.Tours.Find(t => t.Stops.Contains(dest));
int j = destRoute.Stops.IndexOf(dest);
route1.Stops.Remove(city);
destRoute.Stops.Remove(dest);
int routeToAvoid = -1;
if (route1 == destRoute)
{
routeToAvoid = individual.Tours.IndexOf(route1);
}
int source, target;
if (instance.GetDemand(city) >= 0)
{
source = city;
target = dest;
}
else
{
source = dest;
target = city;
}
double bestQuality = double.MaxValue;
int bestTour = -1;
int bestPositionSource = -1;
int bestPositionTarget = -1;
for (int tourIdx = 0; tourIdx < individual.Tours.Count; tourIdx++)
{
if (tourIdx != routeToAvoid)
{
Tour tour = individual.Tours[tourIdx];
VRPEvaluation eval = instance.EvaluateTour(tour, individual);
individual.InsertPair(tour, source, target, instance);
VRPEvaluation evalNew = instance.EvaluateTour(tour, individual);
double delta = evalNew.Quality - eval.Quality;
if (delta < bestQuality &&
(instance.Feasible(evalNew) || allowInfeasible))
{
bestQuality = delta;
bestTour = tourIdx;
bestPositionSource = tour.Stops.IndexOf(source);
bestPositionTarget = tour.Stops.IndexOf(target);
}
tour.Stops.Remove(source);
tour.Stops.Remove(target);
}
}
if (bestTour >= 0)
{
if (bestPositionTarget < bestPositionSource)
{
individual.Tours[bestTour].Stops.Insert(bestPositionTarget, target);
individual.Tours[bestTour].Stops.Insert(bestPositionSource, source);
}
else
{
individual.Tours[bestTour].Stops.Insert(bestPositionSource, source);
individual.Tours[bestTour].Stops.Insert(bestPositionTarget, target);
}
success = true;
}
else
{
if (j < i)
{
destRoute.Stops.Insert(j, dest);
route1.Stops.Insert(i, city);
}
else
{
route1.Stops.Insert(i, city);
destRoute.Stops.Insert(j, dest);
}
success = false;
}
}
else
{
success = false;
}
return(success);
}
public static PotvinEncoding ApplyManipulation(IRandom random, PotvinEncoding individual, IPickupAndDeliveryProblemInstance pdp, bool allowInfeasible) {
PotvinEncoding result = null;
int selectedIndex = SelectRandomTourBiasedByLength(random, individual, pdp);
if (selectedIndex >= 0) {
bool performed = false;
Tour route1 = individual.Tours[selectedIndex];
if (route1.Stops.Count > 0) {
//randomize customer selection
Permutation perm = new Permutation(PermutationTypes.Absolute, route1.Stops.Count, random);
int customer1Position = 0;
while (customer1Position < route1.Stops.Count) {
performed = false;
int customer1 = route1.Stops[perm[customer1Position]];
int customer2 = -1;
for (int i = 0; i < individual.Tours.Count; i++) {
if (i != selectedIndex) {
Tour tour = individual.Tours[i];
for (int customer2Position = 0; customer2Position < tour.Stops.Count; customer2Position++) {
customer2 = tour.Stops[customer2Position];
if (pdp.GetPickupDeliveryLocation(customer1) != customer2) {
result = ReplacePair(individual, pdp, customer2, customer1, allowInfeasible);
if (result != null) {
individual = result;
route1 = individual.Tours[selectedIndex];
performed = true;
break;
}
}
}
}
if (performed) {
break;
}
}
if (!performed)
customer1Position++;
else
break;
}
}
}
return result;
}
public static void ApplyManipulation(IRandom random, PotvinEncoding individual, IPickupAndDeliveryProblemInstance pdp, bool allowInfeasible)
{
int selectedIndex = SelectRandomTourBiasedByLength(random, individual, pdp);
if (selectedIndex >= 0)
{
Tour route1 =
individual.Tours[selectedIndex];
int count = route1.Stops.Count;
if (count > 0)
{
int i = random.Next(0, count);
int city = route1.Stops[i];
if (!PairwiseMove(individual, pdp, city, allowInfeasible))
{
i++;
}
count = route1.Stops.Count;
}
}
}
protected override void EvaluateTour(VRPEvaluation eval, IVRPProblemInstance instance, Tour tour, IVRPEncoding solution)
{
TourInsertionInfo tourInfo = new TourInsertionInfo(solution.GetVehicleAssignment(solution.GetTourIndex(tour)));
eval.InsertionInfo.AddTourInsertionInfo(tourInfo);
double originalQuality = eval.Quality;
IHomogenousCapacitatedProblemInstance cvrpInstance = instance as IHomogenousCapacitatedProblemInstance;
DoubleArray demand = instance.Demand;
ITimeWindowedProblemInstance vrptw = instance as ITimeWindowedProblemInstance;
DoubleArray dueTime = vrptw.DueTime;
DoubleArray readyTime = vrptw.ReadyTime;
DoubleArray serviceTimes = vrptw.ServiceTime;
IPickupAndDeliveryProblemInstance pdp = instance as IPickupAndDeliveryProblemInstance;
IntArray pickupDeliveryLocation = pdp.PickupDeliveryLocation;
double capacity = cvrpInstance.Capacity.Value;
double time = 0.0;
double waitingTime = 0.0;
double serviceTime = 0.0;
double tardiness = 0.0;
double overweight = 0.0;
double distance = 0.0;
double currentLoad = 0.0;
Dictionary <int, bool> stops = new Dictionary <int, bool>();
int pickupViolations = 0;
double tourStartTime = readyTime[0];
time = tourStartTime;
//simulate a tour, start and end at depot
for (int i = 0; i <= tour.Stops.Count; i++)
{
int start = 0;
if (i > 0)
{
start = tour.Stops[i - 1];
}
int end = 0;
if (i < tour.Stops.Count)
{
end = tour.Stops[i];
}
//drive there
double currentDistace = vrptw.GetDistance(start, end, solution);
time += currentDistace;
distance += currentDistace;
double arrivalTime = time;
//check if it was serviced on time
if (time > dueTime[end])
{
tardiness += time - dueTime[end];
}
//wait
double currentWaitingTime = 0.0;
if (time < readyTime[end])
{
currentWaitingTime = readyTime[end] - time;
}
double waitTime = readyTime[end] - time;
waitingTime += currentWaitingTime;
time += currentWaitingTime;
double spareTime = dueTime[end] - time;
//service
double currentServiceTime = serviceTimes[end];
serviceTime += currentServiceTime;
time += currentServiceTime;
//Pickup / deliver
double arrivalSpareCapacity = capacity - currentLoad;
bool validPickupDelivery =
validPickupDelivery =
((demand[end] >= 0) ||
(stops.ContainsKey(pickupDeliveryLocation[end])));
if (validPickupDelivery)
{
currentLoad += demand[end];
}
else
{
pickupViolations++;
}
if (currentLoad > capacity)
{
overweight += currentLoad - capacity;
}
double spareCapacity = capacity - currentLoad;
CVRPPDTWInsertionInfo stopInfo = new CVRPPDTWInsertionInfo(start, end, spareCapacity, tourStartTime,
arrivalTime, time, spareTime, waitTime, new List <int>(stops.Keys), arrivalSpareCapacity);
tourInfo.AddStopInsertionInfo(stopInfo);
stops.Add(end, true);
}
eval.Quality += instance.FleetUsageFactor.Value;
eval.Quality += instance.DistanceFactor.Value * distance;
eval.Distance += distance;
eval.VehicleUtilization += 1;
(eval as CVRPEvaluation).Overload += overweight;
double tourPenalty = 0;
double penalty = overweight * cvrpInstance.OverloadPenalty.Value;
eval.Penalty += penalty;
eval.Quality += penalty;
tourPenalty += penalty;
(eval as CVRPTWEvaluation).Tardiness += tardiness;
(eval as CVRPTWEvaluation).TravelTime += time;
penalty = tardiness * vrptw.TardinessPenalty.Value;
eval.Penalty += penalty;
eval.Quality += penalty;
tourPenalty += penalty;
(eval as CVRPPDTWEvaluation).PickupViolations += pickupViolations;
penalty = pickupViolations * pdp.PickupViolationPenalty.Value;
eval.Penalty += penalty;
tourPenalty += penalty;
eval.Quality += penalty;
eval.Quality += time * vrptw.TimeFactor.Value;
tourInfo.Penalty = tourPenalty;
tourInfo.Quality = eval.Quality - originalQuality;
}
protected override double GetTourInsertionCosts(IVRPProblemInstance instance, IVRPEncoding solution, TourInsertionInfo tourInsertionInfo, int index, int customer,
out bool feasible)
{
CVRPPDTWInsertionInfo insertionInfo = tourInsertionInfo.GetStopInsertionInfo(index) as CVRPPDTWInsertionInfo;
double costs = 0;
feasible = tourInsertionInfo.Penalty < double.Epsilon;
bool tourFeasible = true;
ICapacitatedProblemInstance cvrp = instance as ICapacitatedProblemInstance;
double overloadPenalty = cvrp.OverloadPenalty.Value;
ITimeWindowedProblemInstance vrptw = instance as ITimeWindowedProblemInstance;
DoubleArray dueTime = vrptw.DueTime;
DoubleArray readyTime = vrptw.ReadyTime;
DoubleArray serviceTimes = vrptw.ServiceTime;
double tardinessPenalty = vrptw.TardinessPenalty.Value;
IPickupAndDeliveryProblemInstance pdp = instance as IPickupAndDeliveryProblemInstance;
IntArray pickupDeliveryLocation = pdp.PickupDeliveryLocation;
double pickupPenalty = pdp.PickupViolationPenalty.Value;
double distance = instance.GetDistance(insertionInfo.Start, insertionInfo.End, solution);
double newDistance =
instance.GetDistance(insertionInfo.Start, customer, solution) +
instance.GetDistance(customer, insertionInfo.End, solution);
costs += instance.DistanceFactor.Value * (newDistance - distance);
double demand = instance.Demand[customer];
if (demand > insertionInfo.ArrivalSpareCapacity)
{
tourFeasible = feasible = false;
if (insertionInfo.ArrivalSpareCapacity >= 0)
{
costs += (demand - insertionInfo.ArrivalSpareCapacity) * overloadPenalty;
}
else
{
costs += demand * overloadPenalty;
}
}
int destination = pickupDeliveryLocation[customer];
bool validPickup = true;
if (demand < 0 && !insertionInfo.Visited.Contains(destination))
{
tourFeasible = feasible = false;
validPickup = false;
costs += pickupPenalty;
}
double time = 0;
double tardiness = 0;
if (index > 0)
{
time = (tourInsertionInfo.GetStopInsertionInfo(index - 1) as CVRPTWInsertionInfo).LeaveTime;
}
else
{
time = insertionInfo.TourStartTime;
}
time += instance.GetDistance(insertionInfo.Start, customer, solution);
if (time > dueTime[customer])
{
tardiness += time - dueTime[customer];
}
if (time < readyTime[customer])
{
time += readyTime[customer] - time;
}
time += serviceTimes[customer];
time += instance.GetDistance(customer, insertionInfo.End, solution);
double additionalTime = time - (tourInsertionInfo.GetStopInsertionInfo(index) as CVRPTWInsertionInfo).ArrivalTime;
for (int i = index; i < tourInsertionInfo.GetStopCount(); i++)
{
CVRPTWInsertionInfo nextStop = tourInsertionInfo.GetStopInsertionInfo(i) as CVRPTWInsertionInfo;
if (demand >= 0)
{
if (nextStop.End == destination)
{
demand = 0;
costs -= pickupPenalty;
if (tourInsertionInfo.Penalty == pickupPenalty && tourFeasible)
{
feasible = true;
}
}
else if (nextStop.SpareCapacity < 0)
{
costs += demand * overloadPenalty;
}
else if (nextStop.SpareCapacity < demand)
{
tourFeasible = feasible = false;
costs += (demand - nextStop.SpareCapacity) * overloadPenalty;
}
}
else if (validPickup)
{
if (nextStop.SpareCapacity < 0)
{
costs += Math.Max(demand, nextStop.SpareCapacity) * overloadPenalty;
}
}
if (additionalTime < 0)
{
//arrive earlier than before
//wait probably
if (nextStop.WaitingTime < 0)
{
double wait = nextStop.WaitingTime - additionalTime;
if (wait > 0)
{
additionalTime += wait;
}
}
else
{
additionalTime = 0;
}
//check due date, decrease tardiness
if (nextStop.SpareTime < 0)
{
costs += Math.Max(nextStop.SpareTime, additionalTime) * tardinessPenalty;
}
}
else
{
//arrive later than before, probably don't have to wait
if (nextStop.WaitingTime > 0)
{
additionalTime -= Math.Min(additionalTime, nextStop.WaitingTime);
}
//check due date
if (nextStop.SpareTime > 0)
{
double spare = nextStop.SpareTime - additionalTime;
if (spare < 0)
{
tardiness += -spare;
}
}
else
{
tardiness += additionalTime;
}
}
}
costs += additionalTime * vrptw.TimeFactor.Value;
if (tardiness > 0)
{
tourFeasible = feasible = false;
}
costs += tardiness * tardinessPenalty;
return(costs);
}
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 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);
}
private static PotvinEncoding ReplacePair(PotvinEncoding individual, IVRPProblemInstance instance, int replaced, int replacing, bool allowInfeasible)
{
individual = individual.Clone() as PotvinEncoding;
IPickupAndDeliveryProblemInstance pdp = instance as IPickupAndDeliveryProblemInstance;
int replacedDest = pdp.GetPickupDeliveryLocation(replaced);
int replacedSource, replacedTarget;
if (pdp.GetDemand(replaced) >= 0)
{
replacedSource = replaced;
replacedTarget = replacedDest;
}
else
{
replacedSource = replacedDest;
replacedTarget = replaced;
}
Tour replacedSourceTour = individual.Tours.Find(t => t.Stops.Contains(replacedSource));
Tour replacedTargetTour = individual.Tours.Find(t => t.Stops.Contains(replacedTarget));
int replacingDest = pdp.GetPickupDeliveryLocation(replacing);
int replacingSource, replacingTarget;
if (pdp.GetDemand(replacing) >= 0)
{
replacingSource = replacing;
replacingTarget = replacingDest;
}
else
{
replacingSource = replacingDest;
replacingTarget = replacing;
}
Tour replacingSourceTour = individual.Tours.Find(t => t.Stops.Contains(replacingSource));
Tour replacingTargetTour = individual.Tours.Find(t => t.Stops.Contains(replacingTarget));
replacingSourceTour.Stops.Remove(replacingSource);
replacingTargetTour.Stops.Remove(replacingTarget);
replacedSourceTour.Stops[replacedSourceTour.Stops.IndexOf(replacedSource)] = replacingSource;
if (!allowInfeasible && !instance.TourFeasible(replacedSourceTour, individual))
{
return(null);
}
replacedTargetTour.Stops[replacedTargetTour.Stops.IndexOf(replacedTarget)] = replacingTarget;
if (!allowInfeasible && !instance.TourFeasible(replacedTargetTour, individual))
{
return(null);
}
double bestQuality = double.MaxValue;
int bestTour = -1;
int bestPositionSource = -1;
int bestPositionTarget = -1;
int routeToAvoid = individual.Tours.IndexOf(replacingSourceTour);
for (int tourIdx = 0; tourIdx < individual.Tours.Count; tourIdx++)
{
if (tourIdx != routeToAvoid)
{
Tour tour = individual.Tours[tourIdx];
VRPEvaluation eval = instance.EvaluateTour(tour, individual);
individual.InsertPair(tour, replacedSource, replacedTarget, instance);
VRPEvaluation evalNew = instance.EvaluateTour(tour, individual);
double delta = evalNew.Quality - eval.Quality;
if (delta < bestQuality &&
(instance.Feasible(evalNew) || allowInfeasible))
{
bestQuality = delta;
bestTour = tourIdx;
bestPositionSource = tour.Stops.IndexOf(replacedSource);
bestPositionTarget = tour.Stops.IndexOf(replacedTarget);
}
tour.Stops.Remove(replacedSource);
tour.Stops.Remove(replacedTarget);
}
}
if (bestTour != -1)
{
if (bestPositionTarget < bestPositionSource)
{
individual.Tours[bestTour].Stops.Insert(bestPositionTarget, replacedTarget);
individual.Tours[bestTour].Stops.Insert(bestPositionSource, replacedSource);
}
else
{
individual.Tours[bestTour].Stops.Insert(bestPositionSource, replacedSource);
individual.Tours[bestTour].Stops.Insert(bestPositionTarget, replacedTarget);
}
return(individual);
}
else
{
return(null);
}
}
public static PotvinEncoding ApplyManipulation(IRandom random, PotvinEncoding individual, IPickupAndDeliveryProblemInstance pdp, bool allowInfeasible)
{
PotvinEncoding result = null;
int selectedIndex = SelectRandomTourBiasedByLength(random, individual, pdp);
if (selectedIndex >= 0)
{
bool performed = false;
Tour route1 = individual.Tours[selectedIndex];
if (route1.Stops.Count > 0)
{
//randomize customer selection
Permutation perm = new Permutation(PermutationTypes.Absolute, route1.Stops.Count, random);
int customer1Position = 0;
while (customer1Position < route1.Stops.Count)
{
performed = false;
int customer1 = route1.Stops[perm[customer1Position]];
int customer2 = -1;
for (int i = 0; i < individual.Tours.Count; i++)
{
if (i != selectedIndex)
{
Tour tour = individual.Tours[i];
for (int customer2Position = 0; customer2Position < tour.Stops.Count; customer2Position++)
{
customer2 = tour.Stops[customer2Position];
if (pdp.GetPickupDeliveryLocation(customer1) != customer2)
{
result = ReplacePair(individual, pdp, customer2, customer1, allowInfeasible);
if (result != null)
{
individual = result;
route1 = individual.Tours[selectedIndex];
performed = true;
break;
}
}
}
}
if (performed)
{
break;
}
}
if (!performed)
{
customer1Position++;
}
else
{
break;
}
}
}
}
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();
}