public int FindBestInsertionPlace(Tour tour, int city, int positionToAvoid = -1)
{
if (tour.Stops.Count == 0)
{
return(0);
}
int place = -1;
double minQuality = -1;
VRPEvaluation eval = ProblemInstance.EvaluateTour(tour, this);
for (int i = 0; i <= tour.Stops.Count; i++)
{
if (positionToAvoid != i)
{
bool feasible;
double quality = ProblemInstance.GetInsertionCosts(eval, this, city, 0, i, out feasible);
if (place < 0 || quality < minQuality)
{
place = i;
minQuality = quality;
}
}
}
if (place == -1)
{
place = 0;
}
return(place);
}
private bool FindRouteInsertionPlace(
PotvinEncoding individual,
Tour tour,
int city, bool allowInfeasible, out int place)
{
place = -1;
if (tour.Stops.Contains(city))
{
return(false);
}
if (tour.Stops.Count == 0)
{
place = 0;
return(true);
}
double minDetour = 0;
VRPEvaluation eval = ProblemInstance.EvaluateTour(tour, individual);
bool originalFeasible = ProblemInstance.Feasible(eval);
for (int i = 0; i <= tour.Stops.Count; i++)
{
bool feasible;
double detour = ProblemInstance.GetInsertionCosts(eval, individual, city, 0, i, out feasible);
if (feasible || allowInfeasible)
{
if (place < 0 || detour < minDetour)
{
place = i;
minDetour = detour;
}
}
}
return(place >= 0);
}
public override List <Tour> GetTours()
{
List <Tour> result = new List <Tour>();
int cities = ProblemInstance.Cities.Value;
//Split permutation into vector P
int[] P = new int[cities + 1];
for (int i = 0; i <= cities; i++)
{
P[i] = -1;
}
double[] V = new double[cities + 1];
V[0] = 0;
for (int i = 1; i <= cities; i++)
{
V[i] = double.MaxValue;
}
for (int i = 1; i <= cities; i++)
{
int j = i;
Tour tour = new Tour();
bool feasible = true;
do
{
tour.Stops.Add(this[j - 1] + 1);
VRPEvaluation eval =
ProblemInstance.EvaluateTour(tour, this);
double cost = eval.Quality;
feasible = ProblemInstance.Feasible(eval);
if (feasible || j == i)
{
if (V[i - 1] + cost < V[j])
{
V[j] = V[i - 1] + cost;
P[j] = i - 1;
}
j++;
}
} while (j <= cities && feasible);
}
//extract VRP solution from vector P
int index = 0;
int index2 = cities;
Tour trip = null;
do
{
index = P[index2];
trip = new Tour();
for (int k = index + 1; k <= index2; k++)
{
trip.Stops.Add(this[k - 1] + 1);
}
if (trip.Stops.Count > 0)
{
result.Add(trip);
}
index2 = index;
} while (index != 0);
//if there are too many vehicles - repair
while (result.Count > ProblemInstance.Vehicles.Value)
{
Tour tour = result[result.Count - 1];
//find predecessor / successor in permutation
int predecessorIndex = Array.IndexOf(this.array, tour.Stops[0] - 1) - 1;
if (predecessorIndex >= 0)
{
int predecessor = this[predecessorIndex] + 1;
foreach (Tour t in result)
{
int insertPosition = t.Stops.IndexOf(predecessor) + 1;
if (insertPosition != -1)
{
t.Stops.InsertRange(insertPosition, tour.Stops);
break;
}
}
}
else
{
int successorIndex = Array.IndexOf(this.array,
tour.Stops[tour.Stops.Count - 1] - 1) + 1;
int successor = this[successorIndex] + 1;
foreach (Tour t in result)
{
int insertPosition = t.Stops.IndexOf(successor);
if (insertPosition != -1)
{
t.Stops.InsertRange(insertPosition, tour.Stops);
break;
}
}
}
result.Remove(tour);
}
return(result);
}