These are the official rules for the MiniZinc Challenge 2018.
Version 2.1.7.
These rules were last updated on 8 March 2018.
The MiniZinc Challenge 2018 will test solvers on problems written in MiniZinc 2.1.7.
Let name be the name of the solver system in what follows.
The results will be announced at CP2018. Entrants are encouraged to physically attend CP2018, but are not required to in order to participate or win.
There will be at most five competition CLASSES depending on how many solvers are entered in each of them:
The CLASSES file included in the entry must specify which competition CLASS(es) the entry is to be entered in.
The problem format will be MiniZinc 2.1.7.
There will be some restrictions on the problems tested in MiniZinc challenge.
array[1..3] of set of 1..3: a = [{1,2}, {3}, {1,3}];
var 1..3: i;
constraint card(a[i]) > 1;
var 0..100: x;
var 0..100: y;
constraint x + y < 144;
constraint symmetry_breaking_constraint(x <= y);
and redundant constraints in a predicate "redundant_constraint", e.g.,
array[1..4] of var 0..20: start;
array[1..4] of int: duration = [3, 4, 6, 7];
array[1..4] of int: usage = [6, 3, 5, 3];
constraint cumulative(start, duration, usage, 10);
constraint redundant_constraint(start[1] + dur[1] <= start[3] \/ start[3] + dur[3] <= start[1]);
var 1..5: x;
var 1..5: y;
var 1..5: z;
constraint x <= y /\ y <= z;
solve :: int_search([x, y, z], input_order, indomain_min, complete)
satisfy;
is correct but not
solve :: int_search([x,z], input_order, indomain_min, complete)
satisfy;
even though most FD solvers would know the second was satisfiable.
var 1..5: x;
var 1..10: objective;
constraint x > 1 -> objective > 7;
constraint x = 1 -> objective < 3;
solve :: int_search([x, objective], first_fail, indomain_min, complete)
maximize objective;
will first label x = 1
and find maximum value objective = 2
eventually on
backtracking to the choice x = 1
, then setting x >= 2
in most FD
solvers will have domains for x :: 2..5
and objective :: 8..10
and this time objective
will be selected as the next variable to label.
A full specification of the available choices is given in the
FlatZinc 1.6 specification.
Output from entries must conform to the FlatZinc 1.6 specification. For optimization problems, if the time limit is exceeded before the final solution is printed then the last complete approximate solution printed will be considered to be the solution for that entry. Note that is important that entries flush the output stream after printing each approximate solution.
The benchmarks for MiniZinc Challenge 2018 (as well as for the qualification rounds) will be selected by the judges to try to examine some of the breadth of characteristics of FD solvers:
To obtain benchmarks of suitable difficulty we will select only such instances that can be solved by at least one of the participating solvers in a sensible time-frame. For the qualification rounds no such restriction applies.
In order to collect good benchmarks each entrant is
strongly encouraged to submit
one or two MiniZinc 2.1.5 models, making use of only the global constraints
included in the MiniZinc 2.1.5 library, as well as some (preferably 20)
instance files for each model.
The instances should range from easy (about a minute)
to hard (about 15 minutes) if possible.
Note that the model must conform to the problem format restrictions above.
Submitted benchmarks must be placed in the public domain.
There will be an initial submission round, which will provide the organizers with an opportunity to provide feedback on entries' compatibility with the competition hardware, compliance with the FlatZinc specification and any other matters that may arise. Submission in the initial round is not required in order to qualify for the final round, but it is strongly encouraged.
The challenge will require solvers to process 100 MiniZinc models
with a run-time limit of 20 minutes (process time) per problem.
NOTE that the MiniZinc to FlatZinc/XML-FlatZinc time
will be included in this time.
Each solver s is run on problem p and the following information is collected.
There three different scoring procedure: complete, incomplete, and area. Which one is used for ranking the solver for prices is TBA.
The scoring calculations will be done once for each run class: FD search, Free search, Parallel search, Open class, and Local search. Note that if too few solvers are entered in a class then the challenge won't be run for that class.
The organizers may well run entrants in the FD search class on a series of smaller problems to test that they indeed are following the given search strategy. These problems will not accrue points, but may disqualify an entry from the FD search class.
The solvers will be ranked on total points awarded. There will be prizes for the solvers with the highest scores in each of the run classes: FD search, Free search, Parallel search, Open class, and Local search. The organizers may also award prizes to the best solvers on a particular category of problems. Note that if too few solvers are entered in a class then the challenge won't be run for that class and no prizes will be awarded for that class.
The organizers reserve the right to enter their own systems--or other systems of interest--to the competition, but these will not be eligible for prizes, but still will modify the scoring results. In addition, the organizers reserve the right not to run the challenge on classes with insufficient number of solver entrants.
Return to the MiniZinc Challenge 2018 home page.