/// <summary>
/// Solves the problem.
/// </summary>
/// <returns></returns>
protected override IRoute DoSolve(IProblem problem)
{
bool is_round;
int first;
if (problem.First.HasValue)
{ // the first customer is set.
// test if the last customer is the same.
if (problem.Last == problem.First)
{ // the route is a round.
is_round = true;
first = problem.First.Value;
}
else
{ // the route is not a round.
is_round = false;
first = problem.First.Value;
}
}
else
{ // the first and last customer can be choosen randomly.
is_round = false;
first = -1;
}
// convert the problem to another problem with a virtual depot if needed.
IProblem converted_problem;
if (!is_round && first < 0)
{ // the end points can both vary.
converted_problem = problem.AddVirtualDepot();
}
else
{ // the problem does not need to be converted.
converted_problem = problem;
}
// do the RAI.
IRoute route = RandomizedArbitraryInsertionSolver.DoSolve(this, converted_problem, _route);
// convert the route again if needed.
if (!is_round && first < 0)
{ // the end points could both vary so a virtual one was added. Remove it again here.
List <int> route_list = new List <int>(route);
List <int> new_route_list = new List <int>();
for (int idx = 0; idx < route_list.Count; idx++)
{ // remove customer zero.
if (route_list[idx] > 0)
{
new_route_list.Add(route_list[idx] - 1);
}
}
route = DynamicAsymmetricRoute.CreateFrom(new_route_list, false);
}
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));
}