[prvak]

I use Minizinc in a personal toy project (https://gitlab.com/dustin-space/meal-scheduler), and GECODE or Google's ortools solver at the backend. It's used for meal planning. Unfortunately it's way way slower than I'd hope. I suspect I just have the domain not modeled efficiently. Maybe if I had a few days to put into it, and learn how to properly debug the CSP solver step by step, it might help...

[mzl]

Fun problem. When solving with Gecode, you might want to add the annotation `:: domain_propagation` to the `all_different` constraint (https://www.minizinc.org/doc-2.6.2/en/lib-stdlib-annotations...). Sometimes a good idea, sometimes not.

If you can extract some instances you could send in your problem to the MiniZinc challenge (https://www.minizinc.org/challenge2022/challenge.html), preferably with several instances with varying complexity. The benefit for you is that it is a good way to ensure that your particular problem is tested for a lot of solvers, and may be used for improvments of solvers in the future. The deadline for this years challenge problem submission is 6th of May.

[prvak]

Thanks for the tips!