michieluithetbroek/a-mdvrp

Asymmetric multi-depot vehicle routing problems: valid inequalities and a branch-and-cut algorithm

A-MDVRP

This repository provides the latest C++ implementation of the branch-and-cut framework and the valid inequalities that we used to write "Asymmetric multi-depot vehicle routing problems: valid inequalities and a branch-and-cut algorithm". The exact version as used while writing the manuscript can be found as an online supplement to the publication, see: https://doi.org/10.1287/opre.2020.2033.

If you have any questions, comments, and/or suggestions, please do not hesistate to contact us via [email protected] and [email protected]. If you found our code useful, then you can cite the work as follows:

Uit het Broek, Michiel A. J., Albert H. Schrotenboer, Bolor Jargalsaikhan, Kees Jan Roodbergen, and Leandro C. Coelho (2020). Asymmetric multi-depot routing problems: valid inequalities and a branch-and-cut algorithm. Operations Research.

For further details we refer to our Github wiki page: https://github.com/michieluithetbroek/A-MDVRP/wiki.

a-mdvrp's Issues

Make the Cut base class compatible with Gurobi

The function Cut::getCuts uses the function Cut::createIloRange to translate vector<CutReturn> into vector<IloRange> such that the valid inequalities can be used by CPLEX. We should also add a function that translates our CutReturn objects into objects that can be used by Gurobi.

Do not forget to update the wiki page that describes how to use another solver as this now explains how to use Gurobi.

Generalize the function `Cut::getCuts` such that is works for multiple solvers without the need to edit the function (use templates)

The function Cut::getCuts now returns a vector of CPLEX cuts. If one wants to use Gurobi, then one has to edit the function Cut::getCuts because 1) we need another return type, and 2) we have to call Cut::createGurobiConstraint instead of Cut::createIloRange.

We may avoid this by making Cut::getCuts a template function with two specialized template values (i.e., CPLEX and Gurobi). To avoid that the new template function breaks with the current code we can set the default value of the template to CPLEX.

The function will then be called as

auto const cuts = cut_ptr->getCuts<CPLEX>(model.d_env, model.d_x, x_val, true);