Method propagate

gecode/set/convex/conv.cpp:47–89

  }

  ExecStatus
  Convex::propagate(Space& home, const ModEventDelta&) {
    //I, drop ranges from UB that are shorter than cardMin
    //II, add range LB.smallest to LB.largest to LB
    //III, Drop ranges from UB that do not contain all elements of LB
    //that is: range.min()>LB.smallest or range.max()<LB.largest
    //This leaves only one range.
    //II
    if (x0.glbSize()>0) {
      GECODE_ME_CHECK( x0.include(home,x0.glbMin(),x0.glbMax()) );
    } else {
      //If lower bound is empty, we can still constrain the cardinality
      //maximum with the width of the longest range in UB.
      //No need to do this if there is anything in LB because UB
      //becomes a single range then.
       LubRanges<SetView> ubRangeIt(x0);
       unsigned int maxWidth = 0;
       for (;ubRangeIt();++ubRangeIt) {
         assert(ubRangeIt());
         maxWidth = std::max(maxWidth, ubRangeIt.width());
       }
       GECODE_ME_CHECK( x0.cardMax(home,maxWidth) );
    }


    //I + III

    Region r;
    LubRanges<SetView> ubRangeIt(x0);
    Iter::Ranges::Cache ubRangeItC(r,ubRangeIt);

    for (; ubRangeItC(); ++ubRangeItC) {
      if (ubRangeItC.width() < (unsigned int) x0.cardMin()
          || ubRangeItC.min() > x0.glbMin() //No need to test for empty lb.
          || ubRangeItC.max() < x0.glbMax()
          ) {
        GECODE_ME_CHECK( x0.exclude(home,ubRangeItC.min(), ubRangeItC.max()) );
      }
    }
    if (x0.assigned())
      return home.ES_SUBSUMED(*this);
    return ES_FIX;
  }

}}}