The MiniZinc Challenge is an annual solver competition in the Constraint Programming (CP) community held before the International Conference on Principles and Practice of Constraint Programming. The MiniZinc Challenge 2020 is seeking interesting problem sets on which various constraint solving technologies should be compared on this year. Everyone is allowed to submit problems regardless of whether they are an entrant in the challenge.
There are no restrictions on the kind of problems, but ideally they should be of interesting nature such as practice-related problems and puzzles etc. Problem submissions with real-world instances are particulary welcome. Models for the 2020 challenge can only use integer and Boolean variables.
As in the previous years, we anticipate local search entrants in this years challenge again. Ideally a MiniZinc model should wrap symmetry breaking constraints in a predicate "symmetry_breaking_constraint" defined as
predicate symmetry_breaking_constraint(var bool: c) = c;and wrap redundant constraints in a predicate "redundant_constraint" defined similarly as
predicate redundant_constraint(var bool: c) = c;The aim of this wrapping is that local search solvers can "turn off" symmetry breaking and redundant constraints, in order to improve solving.
The problem submitter provides a MiniZinc model of the problem and at least 20 instances ranging from easy-to-solve to hard-to-solve for an “ordinary” CP system. In addition, there should be at least one "toy" instance for testing purposes. It is strongly encouraged to make use of the global constraint definitions provided in the MiniZinc 2.4 distribution. If you have an instance generator, we are more than happy to receive it. Please, follow the links below for submission instructions and requirements.