Method update

gecode/int/cumulative/tree.hpp:50–53

  }

  forceinline void
  OmegaNode::update(const OmegaNode& l, const OmegaNode& r) {
    e = l.e + r.e; env = std::max(plus(l.env,r.e), r.env);
  }

  template<class TaskView>
  OmegaTree<TaskView>::OmegaTree(Region& r, int c0,