/// <summary>
/// Executes the RAI.
/// </summary>
/// <param name="problem"></param>
/// <param name="solver"></param>
/// <param name="initial_route"></param>
/// <returns></returns>
private static IRoute DoSolve(RandomizedArbitraryInsertionSolver solver, IProblem problem, IRoute initial_route)
{
// initialize a route using best-placement.
DynamicAsymmetricRoute route = null;
if (initial_route == null)
{
OsmSharp.Math.TSP.ArbitraryInsertion.ArbitraryInsertionSolver ai_solver =
new OsmSharp.Math.TSP.ArbitraryInsertion.ArbitraryInsertionSolver();
initial_route = ai_solver.Solve(problem);
}
// get/create the dynamic route.
if (initial_route is DynamicAsymmetricRoute)
{ // initial route is already the correct type.
route = initial_route as DynamicAsymmetricRoute;
}
else
{ // convert the initial route to a route of the correct type.
route = DynamicAsymmetricRoute.CreateFrom(initial_route);
}
// do the Arbitrary Insertion.
double weight = route.CalculateWeight(problem);
int try_count = 0;
while (try_count < (route.Count * route.Count))
{ // keep trying for a given number of times.
int factor = 2;
// cut out a part.
int i = OsmSharp.Math.Random.StaticRandomGenerator.Get().Generate((route.Count / factor) - 1) + 1;
int j = OsmSharp.Math.Random.StaticRandomGenerator.Get().Generate((route.Count / factor) - 1) + 1;
while (i == j)
{
j = OsmSharp.Math.Random.StaticRandomGenerator.Get().Generate((route.Count / factor) - 1) + 1;
}
if (i > j)
{
int k = j;
j = i;
i = k;
}
// cut out the i->j part.
int length = j - i;
if (length > 0)
{
// cut and remove.
DynamicAsymmetricRoute.CutResult cut_result = route.CutAndRemove(
problem, weight, i, length);
// calculate the weight that was removed.
double new_weight = cut_result.Weight;
List <int> cut_part = cut_result.CutPart;
DynamicAsymmetricRoute cut_route = cut_result.Route;
// use best placement to re-insert.
int c = OsmSharp.Math.Random.StaticRandomGenerator.Get().Generate(cut_part.Count);
while (cut_part.Count > 0)
{ // loop until it's empty.
int customer = cut_part[c];
cut_part.RemoveAt(c);
// calculate the best placement.
CheapestInsertionResult result = CheapestInsertionHelper.CalculateBestPlacement(
problem, cut_route, customer);
//cut_route.InsertAfterAndRemove(result.CustomerBefore, result.Customer, result.CustomerAfter);
cut_route.InsertAfter(result.CustomerBefore, result.Customer);
new_weight = new_weight + result.Increase;
// choose next random customer.
c = OsmSharp.Math.Random.StaticRandomGenerator.Get().Generate(cut_part.Count);
}
// descide to keep new route or not.
if (weight > new_weight)
{
route = cut_route;
weight = new_weight;
//if (this.CanRaiseIntermidiateResult())
//{
// this.RaiseIntermidiateResult(route.ToArray<int>(), weight);
//}
}
}
// increase the try count.
try_count++;
}
if (solver != null && solver.CanRaiseIntermidiateResult())
{
solver.RaiseIntermidiateResult(route.ToArray <int>());
}
return(route);
}
/// <summary>
/// Executes the RAI.
/// </summary>
/// <param name="problem"></param>
/// <param name="solver"></param>
/// <param name="initial_route"></param>
/// <returns></returns>
private static IRoute DoSolve(RandomizedArbitraryInsertionSolver solver, IProblem problem, IRoute initial_route)
{
// initialize a route using best-placement.
DynamicAsymmetricRoute route = null;
if (initial_route == null)
{
OsmSharp.Math.TSP.ArbitraryInsertion.ArbitraryInsertionSolver ai_solver =
new OsmSharp.Math.TSP.ArbitraryInsertion.ArbitraryInsertionSolver();
initial_route = ai_solver.Solve(problem);
}
// get/create the dynamic route.
if (initial_route is DynamicAsymmetricRoute)
{ // initial route is already the correct type.
route = initial_route as DynamicAsymmetricRoute;
}
else
{ // convert the initial route to a route of the correct type.
route = DynamicAsymmetricRoute.CreateFrom(initial_route);
}
// do the Arbitrary Insertion.
double weight = route.CalculateWeight(problem);
int try_count = 0;
while (try_count < (route.Count * route.Count))
{ // keep trying for a given number of times.
int factor = 2;
// cut out a part.
int i = OsmSharp.Math.Random.StaticRandomGenerator.Get().Generate((route.Count / factor) - 1) + 1;
int j = OsmSharp.Math.Random.StaticRandomGenerator.Get().Generate((route.Count / factor) - 1) + 1;
while (i == j)
{
j = OsmSharp.Math.Random.StaticRandomGenerator.Get().Generate((route.Count / factor) - 1) + 1;
}
if (i > j)
{
int k = j;
j = i;
i = k;
}
// cut out the i->j part.
int length = j - i;
if (length > 0)
{
// cut and remove.
DynamicAsymmetricRoute.CutResult cut_result = route.CutAndRemove(
problem, weight, i, length);
// calculate the weight that was removed.
double new_weight = cut_result.Weight;
List<int> cut_part = cut_result.CutPart;
DynamicAsymmetricRoute cut_route = cut_result.Route;
// use best placement to re-insert.
int c = OsmSharp.Math.Random.StaticRandomGenerator.Get().Generate(cut_part.Count);
while (cut_part.Count > 0)
{ // loop until it's empty.
int customer = cut_part[c];
cut_part.RemoveAt(c);
// calculate the best placement.
CheapestInsertionResult result = CheapestInsertionHelper.CalculateBestPlacement(
problem, cut_route, customer);
//cut_route.InsertAfterAndRemove(result.CustomerBefore, result.Customer, result.CustomerAfter);
cut_route.InsertAfter(result.CustomerBefore, result.Customer);
new_weight = new_weight + result.Increase;
// choose next random customer.
c = OsmSharp.Math.Random.StaticRandomGenerator.Get().Generate(cut_part.Count);
}
// descide to keep new route or not.
if (weight > new_weight)
{
route = cut_route;
weight = new_weight;
//if (this.CanRaiseIntermidiateResult())
//{
// this.RaiseIntermidiateResult(route.ToArray<int>(), weight);
//}
}
}
// increase the try count.
try_count++;
}
if (solver != null && solver.CanRaiseIntermidiateResult())
{
solver.RaiseIntermidiateResult(route.ToArray<int>());
}
return route;
}
/// <summary>
/// Executes the RAI.
/// </summary>
/// <param name="problem"></param>
/// <param name="initial_route"></param>
/// <returns></returns>
public static IRoute DoSolve(IProblem problem, IRoute initial_route)
{
return(RandomizedArbitraryInsertionSolver.DoSolve(null, problem, initial_route));
}
