Package com.google.ortools.constraintsolver

Class BaseLns

  • public class BaseLns
extends IntVarLocalSearchOperator
    This is the base class for building an Lns operator. An Lns fragment is a
    collection of variables which will be relaxed. Fragments are built with
    NextFragment(), which returns false if there are no more fragments to build.
    Optionally one can override InitFragments, which is called from
    LocalSearchOperator::Start to initialize fragment data.

    Here's a sample relaxing one variable at a time:

    class OneVarLns : public BaseLns {
    public:
    OneVarLns(const std::vector<IntVar*>& vars) : BaseLns(vars), index_(0) {}
    virtual ~OneVarLns() {}
    virtual void InitFragments() { index_ = 0; }
    virtual bool NextFragment() {
    const int size = Size();
    if (index_ < size) {
    AppendToFragment(index_);
    ++index_;
    return true;
    } else {
    return false;
    }
    }

    private:
    int index_;
    };