Class PropAllDiffAC

  • All Implemented Interfaces:
    Comparable<Propagator>, ICause, Identity
    Direct Known Subclasses:

    public class PropAllDiffAC
    extends Propagator<IntVar>
    Propagator for AllDifferent AC constraint for integer variables

    Uses Regin algorithm Runs in O(m.n) worst case time for the initial propagation but has a good average behavior in practice

    Runs incrementally for maintaining a matching

    Jean-Guillaume Fages
    • Constructor Detail

      • PropAllDiffAC

        public PropAllDiffAC​(IntVar[] variables)
        AllDifferent constraint for integer variables enables to control the cardinality of the matching
        variables - array of integer variables
    • Method Detail

      • propagate

        public void propagate​(int evtmask)
                       throws ContradictionException
        Description copied from class: Propagator
        Call the main filtering algorithm to apply to the Domain of the Variable objects. It considers the current state of this objects to remove some values from domains and/or instantiate some variables. Calling this method is done from 2 (and only 2) steps:
        - at the initial propagation step,
        - when involved in a reified constraint.
        It should initialized the internal data structure and apply filtering algorithm from scratch.
        Specified by:
        propagate in class Propagator<IntVar>
        evtmask - type of propagation event this must consider.
        ContradictionException - when a contradiction occurs, like domain wipe out or other incoherencies.
      • isEntailed

        public ESat isEntailed()
        Description copied from class: Propagator
        Check wether this is entailed according to the current state of its internal structure. At least, should check the satisfaction of this (when all is instantiated).
        Specified by:
        isEntailed in class Propagator<IntVar>
        ESat.TRUE if entailed, ESat.FALSE if not entailed, ESat.UNDEFINED if unknown