This work is licensed under a Creative Commons Attribution 4.0 International License. Using constraint programming, an optimal solution with 13 hosts was found by Barbara Smith, et al. They were unable to find an optimal solution using a variety of different ILP methods. The problem is trivially infeasible with just 12 hosts.
Walser reports fast solutions time using a local search procedure and a linear 0-1 encoding.
This work is licensed under a Creative Commons Attribution 4.0 International License.