Method propagate

gecode/int/bin-packing/propagate.cpp:112–357

* Propagation proper * */

   *
   */
  ExecStatus
  Pack::propagate(Space& home, const ModEventDelta& med) {
    // Number of items
    int n = bs.size();
    // Number of bins
    int m = l.size();

    Region region;
    {

      // Possible sizes for bins
      int* s = region.alloc<int>(m);

      for (int j=0; j<m; j++)
        s[j] = 0;

      // Compute sizes for bins
      if (OffsetView::me(med) == ME_INT_VAL) {
        // Also eliminate assigned items
        int k=0;
        for (int i=0; i<n; i++)
          if (bs[i].assigned()) {
            int j = bs[i].bin().val();
            l[j].offset(l[j].offset() - bs[i].size());
            t -= bs[i].size();
          } else {
            for (ViewValues<IntView> j(bs[i].bin()); j(); ++j)
              s[j.val()] += bs[i].size();
            bs[k++] = bs[i];
          }
        n=k; bs.size(n);
      } else {
        for (int i=0; i<n; i++) {
          assert(!bs[i].assigned());
          for (ViewValues<IntView> j(bs[i].bin()); j(); ++j)
            s[j.val()] += bs[i].size();
        }
      }

      // Propagate bin loads and compute lower and upper bound
      int min = t, max = t;
      for (int j=0; j<m; j++) {
        GECODE_ME_CHECK(l[j].gq(home,0));
        GECODE_ME_CHECK(l[j].lq(home,s[j]));
        min -= l[j].max(); max -= l[j].min();
      }

      // Propagate that load must be equal to total size
      for (bool mod = true; mod; ) {
        mod = false; ModEvent me;
        for (int j=0; j<m; j++) {
          int lj_min = l[j].min();
          me = l[j].gq(home, min + l[j].max());
          if (me_failed(me))
            return ES_FAILED;
          if (me_modified(me)) {
            max += lj_min - l[j].min(); mod = true;
          }