square23

benchmark_suitable set_partitioning general_linear

Submitter	Variables	Constraints	Density	Status	Group	Objective	MPS File
Sascha Kurz	11660	7887	9.7737e-03	easy	square	13	square23.mps.gz

Squaring the square For a given integer n, determine the minimum number of squares in a tiling of an \(n\times n\) square using using only integer sided squares of smaller size. (Although the models get quite large even for moderate n, they can be solved to optimality for all \(n \le 61\), while challenging the MIP solver, especially the presolver.)

Location of instance in collection

Instance Statistics

Detailed explanation of the following tables can be found here.

Size Related Properties
	Original	Presolved
Variables	11660	4345
Constraints	7887	572
Binaries	11638	4323
Integers	22	22
Continuous	0	0
Implicit Integers	0	0
Fixed Variables	0	0
Nonzero Density	0.0097737	0.1084950
Nonzeroes	898813	269646

Constraint Classification Properties
	Original	Presolved
Total	7887	572
Empty	0	0
Free	0	0
Singleton	7315	0
Aggregations	0	0
Precedence	0	0
Variable Bound	0	0
Set Partitioning	529	529
Set Packing	0	0
Set Covering	0	0
Cardinality	0	0
Invariant Knapsack	0	0
Equation Knapsack	0	0
Bin Packing	0	0
Knapsack	0	0
Integer Knapsack	0	0
Mixed Binary	0	0
General Linear	43	43
Indicator	0	0

Structure

Available nonzero structure and decomposition information. Further information can be found here.

Nonzero entries of original problem

Nonzero entries after trivial presolving

Decomposed structure of original problem (dec-file)

Decomposed structure after trivial presolving (dec-file)

	value	min	median	mean	max
Components	0.301030
Constraint %		92.4825	92.4825	92.4825	92.4825
Variable %		99.4937	99.4937	99.4937	99.4937
Score	0.004683

Best Known Solution(s)

Find solutions below. Download the archive containing all solutions from the Download page.

ID	Objective	Exact	Int. Viol	Cons. Viol	Obj. Viol	Submitter	Date	Description
1	13	13	0	0	0	-	2018-10-13	Solution found during MIPLIB2017 problem selection.

Similar instances in collection

The following instances are most similar to square23 in the collection. This similarity analysis is based on 100 scaled instance features describing properties of the variables, objective function, bounds, constraints, and right hand sides.

Instance	Status	Variables	Binaries	Integers	Constraints	Nonz.	Submitter	Group	Objective	Tags
square31	easy	28860	28830	30	19435	3937200	Sascha Kurz	square	15	benchmark_suitable set_partitioning general_linear
square37	easy	49320	49284	36	33150	9475672	Sascha Kurz	square	14.9999997973	benchmark_suitable set_partitioning general_linear
square41	easy	62234	62197	37	40160	13566426	Sascha Kurz	square	15	benchmark benchmark_suitable set_partitioning general_linear
square47	easy	95030	94987	43	61591	27329856	Sascha Kurz	square	15.9999999997877	benchmark benchmark_suitable set_partitioning general_linear
mod010	easy	2655	2655	0	146	11203	MIPLIB submission pool	mod	6548	binary set_partitioning cardinality binpacking

Reference

@article{kurz2012squaring,
  title={Squaring the square with integer linear programming},
  author={Kurz, Sascha},
  journal={Journal of Information Processing},
  volume={20},
  number={3},
  pages={680--685},
  year={2012},
}