Method propagate

gecode/int/linear/bool-scale.hpp:251–392

  template<class SBAP, class SBAN, class VX>
  ExecStatus
  EqBoolScale<SBAP,SBAN,VX>::propagate(Space& home, const ModEventDelta& med) {
    int sl_p = 0; // Lower bound, computed positive
    int su_n = 0; // Upper bound, computed negative
    if (BoolView::me(med) == ME_BOOL_VAL) {
      // Eliminate assigned positive views while keeping order
      {
        // Skip not assigned views
        ScaleBool* f = p.fst();
        ScaleBool* l = p.lst();
        while ((f < l) && f->x.none()) {
          su_n += f->a; f++;
        }
        // Copy unassigned views to t
        ScaleBool* t = f;
        while (f < l) {
          if (f->x.one()) {
            c -= f->a;
          } else if (f->x.none()) {
            su_n += f->a; *t = *f; t++;
          }
          f++;
        }
        p.lst(t);
      }
      // Eliminate assigned negative views while keeping order
      {
        // Skip not assigned views
        ScaleBool* f = n.fst();
        ScaleBool* l = n.lst();
        while ((f < l) && f->x.none()) {
          sl_p += f->a; f++;
        }
        // Copy unassigned views to t
        ScaleBool* t = f;
        while (f < l) {
          if (f->x.one()) {
            c += f->a;
          } else if (f->x.none()) {
            sl_p += f->a; *t = *f; t++;
          }
          f++;
        }
        n.lst(t);
      }
    } else {
      for (ScaleBool* f=p.fst(); f<p.lst(); f++)
        su_n += f->a;
      for (ScaleBool* f=n.fst(); f<n.lst(); f++)
        sl_p += f->a;
    }

    if (p.empty() && n.empty()) {
      GECODE_ME_CHECK(x.eq(home,-c));
      return home.ES_SUBSUMED(*this);
    }

    sl_p += x.max() + c;