Saving constraint checks in maintaining coarse-grained generalized arc consistency
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Constraint check plays a central role in establishing generalized arc consistency which is widely used to solve constraint satisfaction problems. In this paper, we propose a new generalized arc consistency algorithm, called GTR, which ensures that the tuples that have been checked to be allowed by a constraint will never be checked again. For each constraint, GTR maintains a dynamic list of the tuples that were checked to be allowed by this constraint and check their validities to identify some values with supports. It is equipped with a mechanism avoiding redundant validity checks. The basic GAC3 algorithm is employed to find a support for the rest values and to add new tuples to the dynamic list. The experiments show that maintaining GTR during search saves a number of constraint checks. It also brings some improvements over cpu time while solving some CSPs with tight constraints.
KeywordsConstraint satisfaction Local consistency Backtracking
This work was supported by the Fundamental Research Funds for the Central Universities (NO. 2412016KJ034), the Education Department of Jilin Province (Project NO. JJKH20170911KJ) and Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education, Jilin University (NO.93K172017K06).
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Conflict of interests
The authors declare that they have no conflicts of interest.
- 2.Bessière C, Fargier H, Lecoutre C (2013) Global inverse consistency for interactive constraint satisfaction Proceedings of CP’13, pp 159–174Google Scholar
- 4.Bessière C, Régin JC (1997) Arc consistency for general constraint networks: preliminary results Proceedings of IJCAI’97, pp 398–404Google Scholar
- 6.Boussemart F, Hemery F, Lecoutre C, Sais L (2004) Boosting systematic search by weighting constraints Proceedings of ECAI’04, pp 146–150Google Scholar
- 7.Gomes C, Selman B, Kautz H (1998) Boosting combinatorial search through randomization Proceedings of AAAI’98, pp 431–437Google Scholar
- 9.Lecoutre C, Boussemart F, Hemery F (2003) Exploiting multidirectionality in coarsegrained arc consistency algorithms Proceedings of CP’03, pp 480–494Google Scholar
- 10.Lecoutre C, Hemery F (2007) A study of residual supports in arc consistency Proceedings of IJCAI’07, pp 125–130Google Scholar
- 11.Lecoutre C, Likitvivatanavong C, Shannon S, Yap R, Zhang Y (2008) Maintaining arc consistency with multiple residues. Constraint Program Lett 2:3–19Google Scholar
- 12.Li H (2017) Narrowing support searching range in maintaining arc consistency for solving constraint satisfaction problems. IEEE access. doi: 10.1109/ACCESS.2017.2690672
- 13.Li H, Liang Y, Guo J, Li Z (2013) Making simple tabular reduction works on negative table constraints Proceedings of AAAI’13, pp 1629–1630Google Scholar
- 14.Likitvivatanavong C, Zhang Y, Bowen J, Freuder EC (2004) Arc consistency in MAC a new perspective Proceedings of CPAI’04 workshop held with CP’04, pp 93–107Google Scholar
- 15.Likitvivatanavong C, Zhang Y, Shannon C, Bowen J, Freuder EC (2007) Arc consistency during search Proceedings of IJCAI’07, pp 137–142Google Scholar
- 18.Sabin D, Freuder EC (1994) Contradicting conventional wisdom in constraint satisfaction Proceedings of ECAI’94, pp 125–129Google Scholar
- 20.van Dongen MRC (2004) Saving support-checks does not always save time. Artif Intell Rev 21:317–334Google Scholar
- 21.Wang R, Xia W, Yap R, Li Z (2016) Optimizing simple table reduction with bitwise representation Proceedings of IJCAI’16, pp 787–793Google Scholar
- 22.Walsh T (1999) Search in a small world Proceedings of IJCAI’99, pp 1172–1177Google Scholar