{"type":"ScholarlyArticle","title":"Optimal and Suboptimal Singleton Arc Consistency Algorithms","authors":[{"name":"Christian Bessière","slug":"christian-bessiere","given":"Christian","family":"Bessiere","affiliation":""},{"name":"Romuald Debruyne","slug":"romuald-debruyne","given":"Romuald","family":"Debruyne","affiliation":""}],"abstract":"Singleton arc consistency (SAC) enhances the pruning capability of arc consistency by ensuring that the network cannot become arc inconsistent after the assignment of a value to a variable. Algorithms have already been proposed to enforce SAC, but they are far from optimal time complexity. We give a lower bound to the time complexity of enforcing SAC, and we propose an algorithm that achieves this complexity, thus being optimal. However, it can be costly in space on large problems. We then propose another SAC algorithm that trades time optimality for a better space complexity. Nevertheless, this last algorithm has a better worst-case time complexity than previously published SAC algorithms. An experimental study shows the good performance of the new algorithms.","doi":null,"url":"https://ijcai.org/proceedings/2005/28","pdf":"https://ijcai.org/proceedings/2005/0028.pdf","markdown":"https://ijcai.org/proceedings/2005/28.md","bibtex":"https://ijcai.org/proceedings/2005/bibtex/28","volume":{"slug":"2005","title":"Proceedings of the Nineteenth International Joint Conference on Artificial Intelligence","short_title":"IJCAI 2005","url":"https://ijcai.org/proceedings/2005/","year":2005,"location":"Edinburgh, Scotland, UK","dates":"","editors":"","isbn":"","publisher":"International Joint Conferences on Artificial Intelligence","doi_prefix":""},"section":null,"track":"","number":28,"pages":{"first":54,"last":58},"keywords":[],"videos":[],"references":[],"license_note":"Copyright International Joint Conferences on Artificial Intelligence."}