Dead-End Elimination for Weighted CSP

  • Simon de Givry
  • Steven D. Prestwich
  • Barry O’Sullivan
Conference paper

DOI: 10.1007/978-3-642-40627-0_22

Part of the Lecture Notes in Computer Science book series (LNCS, volume 8124)
Cite this paper as:
de Givry S., Prestwich S.D., O’Sullivan B. (2013) Dead-End Elimination for Weighted CSP. In: Schulte C. (eds) Principles and Practice of Constraint Programming. CP 2013. Lecture Notes in Computer Science, vol 8124. Springer, Berlin, Heidelberg

Abstract

Soft neighborhood substitutability (SNS) is a powerful technique to automatically detect and prune dominated solutions in combinatorial optimization. Recently, it has been shown in [26] that enforcing partial SNS (PSNSr) during search can be worthwhile in the context of Weighted Constraint Satisfaction Problems (WCSP). However, for some problems, especially with large domains, PSNSr is still too costly to enforce due to its worst-case time complexity in O(ned4) for binary WCSP. We present a simplified dominance breaking constraint, called restricted dead-end elimination (DEEr), the worst-case time complexity of which is in O(ned2). Dead-end elimination was introduced in the context of computational biology as a preprocessing technique to reduce the search space [13, 14, 16, 17, 28, 30]. Our restriction involves testing only one pair of values per variable instead of all the pairs, with the possibility to prune several values at the same time. We further improve the original dead-end elimination criterion, keeping the same time and space complexity as DEEr. Our results show that maintaining DEEr during a depth-first branch and bound (DFBB) search is often faster than maintaining PSNSr and always faster than or similar to DFBB alone.

Keywords

combinatorial optimization dominance rule weighted constraint satisfaction problem soft neighborhood substitutability 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Simon de Givry
    • 1
    • 2
  • Steven D. Prestwich
    • 2
  • Barry O’Sullivan
    • 2
  1. 1.MIA-T, UR 875INRACastanet TolosanFrance
  2. 2.Cork Constraint Computation CentreUniversity College CorkIreland

Personalised recommendations