A Filtering Algorithm for the Stretch Constraint

  • Gilles Pesant
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 2239)


This paper describes a filtering algorithm for a type of constraint that often arises in rostering problems but that also has wider application. Defined on a sequence of variables, the stretch constraint restricts the number of consecutive identical values in the sequence. The algorithm mainly proceeds by determining intervals in which a given stretch must lie and then reasoning about them to filter out values. It is shown to have low time complexity and significant pruning capability as evidenced by experimental results.


Global Constraint Filter Algorithm Shift Variable Shift Type Cyclic Schedule 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2001

Authors and Affiliations

  • Gilles Pesant
    • 1
  1. 1.Centre for Research on TransportationUniversité de MontréalMontrealCanada

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