protected override void Manipulate(IRandom random, GVREncoding individual) {
int customer = random.Next(1, individual.Cities + 1);
Tour tour;
int position;
individual.FindCustomer(customer, out tour, out position);
tour.Stops.RemoveAt(position);
//with a probability of 1/(2*V) create a new tour, else insert at another position
if (individual.GetTours().Count > 0 &&
individual.GetTours().Count < ProblemInstance.Vehicles.Value &&
random.Next(individual.GetTours().Count * 2) == 0) {
Tour newTour = new Tour();
newTour.Stops.Add(customer);
individual.Tours.Add(newTour);
} else {
Tour newTour = individual.Tours[random.Next(individual.Tours.Count)];
int newPosition = random.Next(newTour.Stops.Count + 1);
newTour.Stops.Insert(newPosition, customer);
}
if (tour.Stops.Count == 0)
individual.Tours.Remove(tour);
}
protected override void Manipulate(IRandom random, GVREncoding individual) {
int customer1 = random.Next(1, individual.Cities + 1);
int customer2 = random.Next(1, individual.Cities + 1);
Tour tour1;
int pos1;
individual.FindCustomer(customer1, out tour1, out pos1);
Tour tour2;
int pos2;
individual.FindCustomer(customer2, out tour2, out pos2);
int temp = tour1.Stops[pos1];
tour1.Stops[pos1] = tour2.Stops[pos2];
tour2.Stops[pos2] = temp;
}
protected override void Manipulate(IRandom random, GVREncoding individual)
{
int customer = random.Next(1, individual.Cities + 1);
Tour tour;
int position;
individual.FindCustomer(customer, out tour, out position);
tour.Stops.RemoveAt(position);
//with a probability of 1/(2*V) create a new tour, else insert at another position
if (individual.GetTours().Count > 0 &&
individual.GetTours().Count < ProblemInstance.Vehicles.Value &&
random.Next(individual.GetTours().Count * 2) == 0)
{
Tour newTour = new Tour();
newTour.Stops.Add(customer);
individual.Tours.Add(newTour);
}
else
{
Tour newTour = individual.Tours[random.Next(individual.Tours.Count)];
int newPosition = random.Next(newTour.Stops.Count + 1);
newTour.Stops.Insert(newPosition, customer);
}
if (tour.Stops.Count == 0)
{
individual.Tours.Remove(tour);
}
}
protected override void Manipulate(IRandom random, GVREncoding individual)
{
int customer1 = random.Next(1, individual.Cities + 1);
int customer2 = random.Next(1, individual.Cities + 1);
Tour tour1;
int pos1;
individual.FindCustomer(customer1, out tour1, out pos1);
Tour tour2;
int pos2;
individual.FindCustomer(customer2, out tour2, out pos2);
int temp = tour1.Stops[pos1];
tour1.Stops[pos1] = tour2.Stops[pos2];
tour2.Stops[pos2] = temp;
}
private GVREncoding Crossover(IRandom random, GVREncoding parent1, GVREncoding parent2)
{
GVREncoding child = parent1.Clone() as GVREncoding;
Tour tour = parent2.Tours[random.Next(parent2.Tours.Count)];
int breakPoint1 = random.Next(tour.Stops.Count);
int length = random.Next(1, tour.Stops.Count - breakPoint1 + 1);
List <int> subroute = tour.Stops.GetRange(breakPoint1, length);
//remove duplicates
List <Tour> toBeRemoved = new List <Tour>();
foreach (Tour route in child.Tours)
{
foreach (int city in subroute)
{
route.Stops.Remove(city);
}
if (route.Stops.Count == 0)
{
toBeRemoved.Add(route);
}
}
foreach (Tour route in toBeRemoved)
{
child.Tours.Remove(route);
}
//choose nearest customer
double minDistance = -1;
int customer = -1;
for (int i = 1; i <= ProblemInstance.Cities.Value; i++)
{
if (!subroute.Contains(i))
{
double distance = ProblemInstance.GetDistance(subroute[0], i, child);
if (customer == -1 || distance < minDistance)
{
customer = i;
minDistance = distance;
}
}
}
//insert
if (customer != -1)
{
Tour newTour;
int newPosition;
child.FindCustomer(customer, out newTour, out newPosition);
newTour.Stops.InsertRange(newPosition + 1, subroute);
}
else
{
//special case -> only one tour, whole tour has been chosen as subroute
child = parent1.Clone() as GVREncoding;
}
return(child);
}