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 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);
}