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MiniZinc Challenge 2015 Results


The entrants for this year (with their descriptions, when provided):

In addition, the challenge organisers entered the following FlatZinc and MiniZinc implementations:

  • chuffed (description). A C++ FD solver using lazy clause generation.
  • MZN/CPLEX. Translates to MIP, uses CPLEX Optimizer version 12.6.1.
  • G12/FD. A Mercury FD solver (the G12 FlatZinc interpreter's default solver).
  • Gecode (description). A C++ FD solver.
  • MZN/Gurobi. Translates to MIP, uses Gurobi Optimizer version 6.0.4.
  • sunny-cp (description). A multi-threaded CP portfolio solver using 13 different CP and MIP solvers incl. chuffed, G12 solvers, Gecode.

As per the challenge rules, these entries are not eligible for prizes, but do modify the scoring results. Furthermore, entries in the FD search category (JaCoP) were automatically included in the free search category, while entries in the free search category (Concrete, chuffed, G12/FD, MinisatID, MinisatID-MP, Mistral, Opturion CPX, OscaR/CBLS, Picat CP, Picat SAT and promoted FD entries) were automatically included in the parallel search category. Lastly, all entries in the parallel search category and promoted entries into that category were automatically included in the open search category.

Summary of Results

The results for the MiniZinc Challenge 2015 were

FixedOpturion CPXOR-ToolsJaCoP
FreeOpturion CPXiZplusOR-Tools
ParallelOR-ToolsOpturion CPXChoco
Opensunny-cp——OR-ToolsOpturion CPX

Description of Results

All times are given in milliseconds.

A score of 0.0 indicates a worse answer in quality (worse objective, no proof of optimality, or no answer for satisfaction problems), 1.0 a better solution in quality. When the quality is the same, the 1.0 purse is split with respect to time used.

If a promoted entry does not recognize an option (or states that it is just ignored), times and solutions from the previous category are used for scoring. The suffixes -fd, -free, -par or -open (for the parallel portfolio solver entered) at the end of the solvers names indicate which configuration the solvers were run with.

mzn2fzn was run with the same time and memory limits as the solvers.

In the Status column:

  • S indicates that a solution was found,
  • C indicates that the search was complete,
  • UNK indicates an incorrect answer OR
  • UNK indicates that flattening aborted (time-out or out-of-memory) OR
  • UNK indicates that no answer was returned in the time limit or the solver aborted.

Download all problems

All problems are available in a zipped tar-ball here.


Select a list of solvers and benchmarks and click on “Compute Results” to score the solvers against each other on the selected benchmarks. The entrants for each of the fd search, free search and parallel search categories can be selected with the corresponding buttons.

Solver selection: Problem selection:


Total per problem:

Solver Score Score Incomplete
Problem Solver Score Score Incomplete

Individual results:

Problem Instance Solver Status Time Objective Score Score Incomplete

Global constraint per model

The following table lists the global constraints used by each model in this year's challenge. In addition, the columns RC and SBC respectively indicates whether the model contains redundant or/and symmetry breaking constraints.

ProblemTypeKindRCSBCMiniZinc Globals
gfd-schedulecombiminnvalue, at_most
isrealmincircuit, table
mappingrealminbin_packing_load, count, maximum, network_flow_cost
p1fcombiminall_different, inverse, lex_less
rostercombiminat_least, at_most, exactly

The files on this page are for MiniZinc version 2.0.4.