Once you have written a description of your problem, you can use Dispatcher classes to model it.

Open the example file YourDispatcherHome/examples/src/tutorial/cost1_partial.cpp in your development environment.

This problem is modeled as for a PDP, with only the creation and addition of a cost coefficient function.

Add the following code after the comment
//Create the LastVisitCostCoef function

IloNum LastVisitCostCoef(IloVisit visit) {
  IloNode node = visit.getNode();
  return ((IloInt)(node.getX()) % 5) + 1;
}

The LastVisitCostCoef is a function of the type IloSimpleVisitToNumFunction, and it creates the cost coefficient from the x-coordinate of visit.

Next, you set the vehicle cost in the createVehicles function.

Add the following code after the comment //Add the cost function.

    IloVisitToNumFunction coefFunction(_env, LastVisitCostCoef);
    vehicle.setCost(distance,
                    coefFunction,
                    vehicle.getLastVisit().getPrevVar());

These lines in createVehicles create the vehicle cost. coefFunction is created as an IloVisitToNumFunction which allows you to associate IloNum values with visits.

The member function IloVehicle::setCost is used here to associate a visit-dependent proportional cost with vehicle. The parameter vehicle.getLastVisit().getPrevVar() returns the location variable with which coefFunction calculates the cost applied to distance. Note that the visit returned by vehicle.getLastVisit().getPrevVar() corresponds to the last customer visit performed before returning to the depot.