no code implementations • 2 Oct 2023 • Joan Espasa, Ian P. Gent, Ian Miguel, Peter Nightingale, András Z. Salamon, Mateu Villaret
We report on progress in modelling and solving Puzznic, a video game requiring the player to plan sequences of moves to clear a grid by matching blocks.
no code implementations • 2 Oct 2023 • Joan Espasa, Ian Miguel, Peter Nightingale, András Z. Salamon, Mateu Villaret
We study a planning problem based on Plotting, a tile-matching puzzle video game published by Taito in 1989.
1 code implementation • 18 Jul 2023 • Felix Ulrich-Oltean, Peter Nightingale, James Alfred Walker
We show that it is possible to select encodings effectively using a standard set of features for constraint problems; however we obtain better performance with a new set of features specifically designed for the pseudo-Boolean and linear constraints.
1 code implementation • 29 May 2022 • Nguyen Dang, Özgür Akgün, Joan Espasa, Ian Miguel, Peter Nightingale
This separation presents an opportunity for automated approaches to generate instance data that define instances that are graded (solvable at a certain difficulty level for a solver) or can discriminate between two solving approaches.
no code implementations • 26 Feb 2022 • Özgür Akgün, Ian P. Gent, Christopher Jefferson, Zeynep Kiziltan, Ian Miguel, Peter Nightingale, András Z. Salamon, Felix Ulrich-Oltean
The performance of a constraint model can often be improved by converting a subproblem into a single table constraint.
no code implementations • 12 Nov 2021 • Peter Nightingale
We describe the constraint modelling tool Savile Row, its input language and its main features.
no code implementations • 1 Nov 2021 • Özgür Akgün, Alan M. Frisch, Ian P. Gent, Christopher Jefferson, Ian Miguel, Peter Nightingale, András Z. Salamon
The Essence language allows a user to specify a constraint problem at a level of abstraction above that at which constraint modelling decisions are made.
no code implementations • 15 Oct 2021 • Miquel Bofill, Jordi Coll, Peter Nightingale, Josep Suy, Felix Ulrich-Oltean, Mateu Villaret
When solving a combinatorial problem using propositional satisfiability (SAT), the encoding of the problem is of vital importance.
no code implementations • 29 Mar 2018 • Ian P. Gent, Ciaran McCreesh, Ian Miguel, Neil C. A. Moore, Peter Nightingale, Patrick Prosser, Chris Unsworth
As multicore computing is now standard, it seems irresponsible for constraints researchers to ignore the implications of it.
no code implementations • 12 Jan 2016 • Peter Nightingale, Andrea Rendl
A description of the Essence' language as used by the tool Savile Row.
no code implementations • 22 Apr 2015 • James Caldwell, Ian P. Gent, Peter Nightingale
One key concept in constraint programming is propagation: reasoning on a constraint or set of constraints to derive new facts, typically to remove values from the domains of decision variables.
no code implementations • 4 Feb 2014 • Peter Nightingale, Ian Philip Gent, Christopher Jefferson, Ian Miguel
We also introduce a variant algorithm HaggisGAC-Stable, which is adapted to avoid work on backtracking and in some cases can be faster and have significant reductions in memory use.