routing_neighborhoods.h

// Copyright 2010-2018 Google LLC
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef OR_TOOLS_CONSTRAINT_SOLVER_ROUTING_NEIGHBORHOODS_H_
#define OR_TOOLS_CONSTRAINT_SOLVER_ROUTING_NEIGHBORHOODS_H_

#include "ortools/constraint_solver/constraint_solver.h"
#include "ortools/constraint_solver/constraint_solveri.h"
#include "ortools/constraint_solver/routing_types.h"

namespace operations_research {

// Relocate neighborhood which moves chains of neighbors.
// The operator starts by relocating a node n after a node m, then continues
// moving nodes which were after n as long as the "cost" added is less than
// the "cost" of the arc (m, n). If the new chain doesn't respect the domain of
// next variables, it will try reordering the nodes.
// Possible neighbors for path 1 -> A -> B -> C -> D -> E -> 2 (where (1, 2) are
// first and last nodes of the path and can therefore not be moved, A must
// be performed before B, and A, D and E are located at the same place):
// 1 -> A -> C -> [B] -> D -> E -> 2
// 1 -> A -> C -> D -> [B] -> E -> 2
// 1 -> A -> C -> D -> E -> [B] -> 2
// 1 -> A -> B -> D -> [C] -> E -> 2
// 1 -> A -> B -> D -> E -> [C] -> 2
// 1 -> A -> [D] -> [E] -> B -> C -> 2
// 1 -> A -> B -> [D] -> [E] ->  C -> 2
// 1 -> A -> [E] -> B -> C -> D -> 2
// 1 -> A -> B -> [E] -> C -> D -> 2
// 1 -> A -> B -> C -> [E] -> D -> 2
// This operator is extremely useful to move chains of nodes which are located
// at the same place (for instance nodes part of a same stop).
// TODO(user): Consider merging with standard Relocate in local_search.cc.
class MakeRelocateNeighborsOperator : public PathWithPreviousNodesOperator {
 public:
  MakeRelocateNeighborsOperator(
      const std::vector<IntVar*>& vars,
      const std::vector<IntVar*>& secondary_vars,
      std::function<int(int64)> start_empty_path_class,
      RoutingTransitCallback2 arc_evaluator);
  ~MakeRelocateNeighborsOperator() override {}

  bool MakeNeighbor() override;
  std::string DebugString() const override { return "RelocateNeighbors"; }

 private:
  // Moves a chain starting after 'before_chain' and ending at 'chain_end'
  // after node 'destination'. Tries to repair the resulting solution by
  // checking if the new arc created after 'destination' is compatible with
  // NextVar domains, and moves the 'destination' down the path if the solution
  // is inconsistent. Iterates the process on the new arcs created before
  // the node 'destination' (if destination was moved).
  bool MoveChainAndRepair(int64 before_chain, int64 chain_end,
                          int64 destination);

  // Moves node after 'before_to_move' down the path until a position is found
  // where NextVar domains are not violated, if it exists. Stops when reaching
  // position after 'up_to'.
  // If the node was not moved (either because the current position does not
  // violate any domains or because not such position could be found), returns
  // -1. If the node was moved to a new position before up_to, returns up_to;
  // if it was moved just after up_to returns the node which was after up_to.
  int64 Reposition(int64 before_to_move, int64 up_to);

  RoutingTransitCallback2 arc_evaluator_;
};

// Pair-based neighborhood operators, designed to move nodes by pairs (pairs
// are static and given). These neighborhoods are very useful for Pickup and
// Delivery problems where pickup and delivery nodes must remain on the same
// route.
// TODO(user): Add option to prune neighbords where the order of node pairs
//                is violated (ie precedence between pickup and delivery nodes).
// TODO(user): Move this to local_search.cc if it's generic enough.
// TODO(user): Detect pairs automatically by parsing the constraint model;
//                we could then get rid of the pair API in the RoutingModel
//                class.

// Operator which inserts pairs of inactive nodes into a path.
// Possible neighbors for the path 1 -> 2 -> 3 with pair (A, B) inactive
// (where 1 and 3 are first and last nodes of the path) are:
//   1 -> [A] -> [B] ->  2  ->  3
//   1 -> [B] ->  2 ->  [A] ->  3
//   1 -> [A] ->  2  -> [B] ->  3
//   1 ->  2  -> [A] -> [B] ->  3
// Note that this operator does not expicitely insert the nodes of a pair one
// after the other which forbids the following solutions:
//   1 -> [B] -> [A] ->  2  ->  3
//   1 ->  2  -> [B] -> [A] ->  3
// which can only be obtained by inserting A after B.
class MakePairActiveOperator : public PathOperator {
 public:
  MakePairActiveOperator(const std::vector<IntVar*>& vars,
                         const std::vector<IntVar*>& secondary_vars,
                         std::function<int(int64)> start_empty_path_class,
                         const RoutingIndexPairs& pairs);
  ~MakePairActiveOperator() override {}
  bool MakeNextNeighbor(Assignment* delta, Assignment* deltadelta) override;
  bool MakeNeighbor() override;
  std::string DebugString() const override { return "MakePairActive"; }

 protected:
  bool OnSamePathAsPreviousBase(int64 base_index) override {
    // Both base nodes have to be on the same path since they represent the
    // nodes after which unactive node pairs will be moved.
    return true;
  }

  int64 GetBaseNodeRestartPosition(int base_index) override;

  // Required to ensure that after synchronization the operator is in a state
  // compatible with GetBaseNodeRestartPosition.
  bool RestartAtPathStartOnSynchronize() override { return true; }

 private:
  void OnNodeInitialization() override;

  int inactive_pair_;
  RoutingIndexPairs pairs_;
};

// Operator which makes pairs of active nodes inactive.
class MakePairInactiveOperator : public PathWithPreviousNodesOperator {
 public:
  MakePairInactiveOperator(const std::vector<IntVar*>& vars,
                           const std::vector<IntVar*>& secondary_vars,
                           std::function<int(int64)> start_empty_path_class,
                           const RoutingIndexPairs& index_pairs);

  bool MakeNeighbor() override;
  std::string DebugString() const override { return "MakePairInActive"; }

 private:
  std::vector<int> pairs_;
};

// Operator which moves a pair of nodes to another position where the first
// node of the pair must be before the second node on the same path.
// Possible neighbors for the path 1 -> A -> B -> 2 -> 3 (where (1, 3) are
// first and last nodes of the path and can therefore not be moved, and (A, B)
// is a pair of nodes):
//   1 -> [A] ->  2  -> [B] -> 3
//   1 ->  2  -> [A] -> [B] -> 3
// The pair can be moved to another path.
class PairRelocateOperator : public PathWithPreviousNodesOperator {
 public:
  PairRelocateOperator(const std::vector<IntVar*>& vars,
                       const std::vector<IntVar*>& secondary_vars,
                       std::function<int(int64)> start_empty_path_class,
                       const RoutingIndexPairs& index_pairs);
  ~PairRelocateOperator() override {}

  bool MakeNeighbor() override;
  std::string DebugString() const override { return "PairRelocateOperator"; }

 protected:
  bool OnSamePathAsPreviousBase(int64 base_index) override {
    // Both destination nodes must be on the same path.
    return base_index == kPairSecondNodeDestination;
  }
  int64 GetBaseNodeRestartPosition(int base_index) override;

 private:
  bool RestartAtPathStartOnSynchronize() override { return true; }

  std::vector<int> pairs_;
  std::vector<bool> is_first_;
  static const int kPairFirstNode = 0;
  static const int kPairFirstNodeDestination = 1;
  static const int kPairSecondNodeDestination = 2;
};

class LightPairRelocateOperator : public PathWithPreviousNodesOperator {
 public:
  LightPairRelocateOperator(const std::vector<IntVar*>& vars,
                            const std::vector<IntVar*>& secondary_vars,
                            std::function<int(int64)> start_empty_path_class,
                            const RoutingIndexPairs& index_pairs);
  ~LightPairRelocateOperator() override {}

  bool MakeNeighbor() override;
  std::string DebugString() const override {
    return "LightPairRelocateOperator";
  }

 private:
  std::vector<int> pairs_;
};

// Operator which exchanges the position of two pairs; for both pairs the first
// node of the pair must be before the second node on the same path.
// Possible neighbors for the paths 1 -> A -> B -> 2 -> 3 and 4 -> C -> D -> 5
// (where (1, 3) and (4, 5) are first and last nodes of the paths and can
// therefore not be moved, and (A, B) and (C,D) are pairs of nodes):
//   1 -> [C] ->  [D] -> 2 -> 3, 4 -> [A] -> [B] -> 5
class PairExchangeOperator : public PathWithPreviousNodesOperator {
 public:
  PairExchangeOperator(const std::vector<IntVar*>& vars,
                       const std::vector<IntVar*>& secondary_vars,
                       std::function<int(int64)> start_empty_path_class,
                       const RoutingIndexPairs& index_pairs);
  ~PairExchangeOperator() override {}

  bool MakeNeighbor() override;
  std::string DebugString() const override { return "PairExchangeOperator"; }

 private:
  bool RestartAtPathStartOnSynchronize() override { return true; }
  bool GetPreviousAndSibling(int64 node, int64* previous, int64* sibling,
                             int64* sibling_previous) const;

  std::vector<int> pairs_;
  std::vector<bool> is_first_;
};

// Operator which exchanges the paths of two pairs (path have to be different).
// Pairs are inserted in all possible positions in their new path with the
// constraint that the second node must be placed after the first.
// Possible neighbors for the path 1 -> A -> B -> 2 -> 3, 4 -> C -> 5 -> D -> 6
// 1 -> C -> D -> 2 -> 3 4 -> A -> B -> 5 -> 6
// 1 -> C -> 2 -> D -> 3 4 -> A -> 5 -> B -> 6
// 1 -> 2 -> C -> D -> 3 4 -> 5 -> A -> B -> 6
// 1 -> C -> D -> 2 -> 3 4 -> A -> B -> 5 -> 6
// 1 -> C -> 2 -> D -> 3 4 -> A -> 5 -> B -> 6
// 1 -> 2 -> C -> D -> 3 4 -> 5 -> A -> B -> 6
// 1 -> C -> D -> 2 -> 3 4 -> A -> B -> 5 -> 6
// 1 -> C -> 2 -> D -> 3 4 -> A -> 5 -> B -> 6
// 1 -> 2 -> C -> D -> 3 4 -> 5 -> A -> B -> 6
class PairExchangeRelocateOperator : public PathWithPreviousNodesOperator {
 public:
  PairExchangeRelocateOperator(const std::vector<IntVar*>& vars,
                               const std::vector<IntVar*>& secondary_vars,
                               std::function<int(int64)> start_empty_path_class,
                               const RoutingIndexPairs& index_pairs);
  ~PairExchangeRelocateOperator() override {}

  bool MakeNeighbor() override;
  std::string DebugString() const override {
    return "PairExchangeRelocateOperator";
  }

 protected:
  bool OnSamePathAsPreviousBase(int64 base_index) override;
  int64 GetBaseNodeRestartPosition(int base_index) override;

 private:
  bool RestartAtPathStartOnSynchronize() override { return true; }
  bool GetPreviousAndSibling(int64 node, int64* previous, int64* sibling,
                             int64* sibling_previous) const;
  bool MoveNode(int pair, int node, int64 nodes[2][2], int64 dest[2][2],
                int64 prev[2][2]);
  bool LoadAndCheckDest(int pair, int node, int64 base_node, int64 nodes[2][2],
                        int64 dest[2][2]) const;

  std::vector<int> pairs_;
  std::vector<bool> is_first_;
  static const int kFirstPairFirstNode = 0;
  static const int kSecondPairFirstNode = 1;
  static const int kFirstPairFirstNodeDestination = 2;
  static const int kFirstPairSecondNodeDestination = 3;
  static const int kSecondPairFirstNodeDestination = 4;
  static const int kSecondPairSecondNodeDestination = 5;
};

// Operator which iterates through each alternative of a set of pairs. If a
// pair has n and m alternatives, n.m alternatives will be explored.
// Possible neighbors for the path 1 -> A -> a -> 2 (where (1, 2) are first and
// last nodes of a path and A has B, C as alternatives and a has b as
// alternative):
// 1 -> A -> [b] -> 2
// 1 -> [B] -> a -> 2
// 1 -> [B] -> [b] -> 2
// 1 -> [C] -> a -> 2
// 1 -> [C] -> [b] -> 2
class SwapIndexPairOperator : public IntVarLocalSearchOperator {
 public:
  SwapIndexPairOperator(const std::vector<IntVar*>& vars,
                        const std::vector<IntVar*>& path_vars,
                        const RoutingIndexPairs& index_pairs);
  ~SwapIndexPairOperator() override {}

  bool MakeNextNeighbor(Assignment* delta, Assignment* deltadelta) override;
  void OnStart() override;
  std::string DebugString() const override { return "SwapIndexPairOperator"; }

 private:
  // Updates first_active_ and second_active_ to make them correspond to the
  // active nodes of the node pair of index pair_index_.
  bool UpdateActiveNodes();
  // Sets the to to be the node after from
  void SetNext(int64 from, int64 to, int64 path) {
    DCHECK_LT(from, number_of_nexts_);
    SetValue(from, to);
    if (!ignore_path_vars_) {
      DCHECK_LT(from + number_of_nexts_, Size());
      SetValue(from + number_of_nexts_, path);
    }
  }

  const RoutingIndexPairs index_pairs_;
  int pair_index_;
  int first_index_;
  int second_index_;
  int64 first_active_;
  int64 second_active_;
  std::vector<int64> prevs_;
  const int number_of_nexts_;
  const bool ignore_path_vars_;
};

// Operator which inserts inactive nodes into a path and makes a pair of
// active nodes inactive.
class IndexPairSwapActiveOperator : public PathWithPreviousNodesOperator {
 public:
  IndexPairSwapActiveOperator(const std::vector<IntVar*>& vars,
                              const std::vector<IntVar*>& secondary_vars,
                              std::function<int(int64)> start_empty_path_class,
                              const RoutingIndexPairs& index_pairs);
  ~IndexPairSwapActiveOperator() override {}

  bool MakeNextNeighbor(Assignment* delta, Assignment* deltadelta) override;
  bool MakeNeighbor() override;
  std::string DebugString() const override {
    return "IndexPairSwapActiveOperator";
  }

 private:
  void OnNodeInitialization() override;

  int inactive_node_;
  std::vector<int> pairs_;
};

// ----- RelocateExpensiveChain -----
// Operator which relocates the most expensive subchains (given a cost callback)
// in a path to a different position.
// The most expensive chain on a path is the one resulting from cutting the 2
// most expensive arcs on this path.
class RelocateExpensiveChain : public PathOperator {
 public:
  RelocateExpensiveChain(
      const std::vector<IntVar*>& vars,
      const std::vector<IntVar*>& secondary_vars,
      std::function<int(int64)> start_empty_path_class,
      int num_arcs_to_consider,
      std::function<int64(int64, int64, int64)> arc_cost_for_path_start);
  ~RelocateExpensiveChain() override {}
  bool MakeNeighbor() override;
  bool MakeOneNeighbor() override;

  std::string DebugString() const override { return "RelocateExpensiveChain"; }

 private:
  void OnNodeInitialization() override;
  void IncrementCurrentPath();
  bool IncrementCurrentArcIndices();
  // Returns false if current_path_ is empty. Otherwise sets
  // current_expensive_chain_ to the pair of {"preceding", "last"} nodes
  // corresponding to the most expensive chain on current_path_, and returns
  // true.
  bool FindMostExpensiveChainsOnCurrentPath();
  // Calls FindMostExpensiveChainOnCurrentPath() on remaining paths until one
  // of them returns true. Returns false if all remaining paths are empty.
  bool FindMostExpensiveChainsOnRemainingPaths();

  int num_arcs_to_consider_;
  int current_path_;
  std::vector<std::pair<int64, int> > most_expensive_arc_starts_and_ranks_;
  // Indices in most_expensive_arc_starts_and_ranks_ corresponding to the first
  // and second arcs currently being considered for removal.
  std::pair</*first_arc_index*/ int, /*second_arc_index*/ int>
      current_expensive_arc_indices_;
  std::function<int64(/*before_node*/ int64, /*after_node*/ int64,
                      /*path_start*/ int64)>
      arc_cost_for_path_start_;
  int end_path_;
  // The following boolean indicates if there are any non-empty paths left to
  // explore by the operator.
  bool has_non_empty_paths_to_explore_;
};

// Operator which inserts pairs of inactive nodes into a path and makes an
// active node inactive.
// There are two versions:
// - one which makes inactive the node being replaced by the first node of the
//   pair (with swap_first true);
// - one which makes inactive the node being replaced by the second node of the
//   pair (with swap_first false).
template <bool swap_first>
class PairNodeSwapActiveOperator : public PathOperator {
 public:
  PairNodeSwapActiveOperator(const std::vector<IntVar*>& vars,
                             const std::vector<IntVar*>& secondary_vars,
                             std::function<int(int64)> start_empty_path_class,
                             const RoutingIndexPairs& index_pairs);
  ~PairNodeSwapActiveOperator() override {}

  bool MakeNextNeighbor(Assignment* delta, Assignment* deltadelta) override;
  bool MakeNeighbor() override;
  std::string DebugString() const override {
    return "PairNodeSwapActiveOperator";
  }

 protected:
  bool OnSamePathAsPreviousBase(int64 base_index) override {
    // Both base nodes have to be on the same path since they represent the
    // nodes after which unactive node pairs will be moved.
    return true;
  }

  int64 GetBaseNodeRestartPosition(int base_index) override;

  // Required to ensure that after synchronization the operator is in a state
  // compatible with GetBaseNodeRestartPosition.
  bool RestartAtPathStartOnSynchronize() override { return true; }

 private:
  void OnNodeInitialization() override;

  int inactive_pair_;
  RoutingIndexPairs pairs_;
};

// ==========================================================================
// Section: Implementations of the template classes declared above.

template <bool swap_first>
PairNodeSwapActiveOperator<swap_first>::PairNodeSwapActiveOperator(
    const std::vector<IntVar*>& vars,
    const std::vector<IntVar*>& secondary_vars,
    std::function<int(int64)> start_empty_path_class,
    const RoutingIndexPairs& index_pairs)
    : PathOperator(vars, secondary_vars, 2, false,
                   std::move(start_empty_path_class)),
      inactive_pair_(0),
      pairs_(index_pairs) {}

template <bool swap_first>
int64 PairNodeSwapActiveOperator<swap_first>::GetBaseNodeRestartPosition(
    int base_index) {
  // Base node 1 must be after base node 0 if they are both on the same path.
  if (base_index == 0 || StartNode(base_index) != StartNode(base_index - 1)) {
    return StartNode(base_index);
  } else {
    return BaseNode(base_index - 1);
  }
}

template <bool swap_first>
void PairNodeSwapActiveOperator<swap_first>::OnNodeInitialization() {
  for (int i = 0; i < pairs_.size(); ++i) {
    if (IsInactive(pairs_[i].first[0]) && IsInactive(pairs_[i].second[0])) {
      inactive_pair_ = i;
      return;
    }
  }
  inactive_pair_ = pairs_.size();
}

template <bool swap_first>
bool PairNodeSwapActiveOperator<swap_first>::MakeNextNeighbor(
    Assignment* delta, Assignment* deltadelta) {
  while (inactive_pair_ < pairs_.size()) {
    if (!IsInactive(pairs_[inactive_pair_].first[0]) ||
        !IsInactive(pairs_[inactive_pair_].second[0]) ||
        !PathOperator::MakeNextNeighbor(delta, deltadelta)) {
      ResetPosition();
      ++inactive_pair_;
    } else {
      return true;
    }
  }
  return false;
}

template <bool swap_first>
bool PairNodeSwapActiveOperator<swap_first>::MakeNeighbor() {
  const int64 base = BaseNode(0);
  if (IsPathEnd(base)) {
    return false;
  }
  const int64 pair_first = pairs_[inactive_pair_].first[0];
  const int64 pair_second = pairs_[inactive_pair_].second[0];
  if (swap_first) {
    return MakeActive(pair_second, BaseNode(1)) &&
           MakeActive(pair_first, base) &&
           MakeChainInactive(pair_first, Next(pair_first));
  } else {
    return MakeActive(pair_second, BaseNode(1)) &&
           MakeActive(pair_first, base) &&
           MakeChainInactive(pair_second, Next(pair_second));
  }
}

// Tries to move subtrips after an insertion node.
// A subtrip is a subsequence that contains only matched pickup and delivery
// nodes, or pickup-only nodes, i.e. it cannot contain a pickup without a
// corresponding delivery or vice-versa.
// For a given subtrip given by path indices i_1 ... i_k, we call 'rejected' the
// nodes with indices i_1 < j < i_k that are not in the subtrip.
// If the base_node is a pickup, this operator selects the smallest subtrip
// starting at base_node such that rejected nodes are only deliveries.
// If the base_node is a delivery, it selects the smallest subtrip ending at
// base_node such that rejected nodes are only pickups.
class RelocateSubtrip : public PathWithPreviousNodesOperator {
 public:
  RelocateSubtrip(const std::vector<IntVar*>& vars,
                  const std::vector<IntVar*>& secondary_vars,
                  std::function<int(int64)> start_empty_path_class,
                  const RoutingIndexPairs& pairs);

  std::string DebugString() const override { return "RelocateSubtrip"; }
  bool MakeNeighbor() override;

 private:
  // Relocates the subtrip starting at chain_first_node. It must be a pickup.
  bool RelocateSubTripFromPickup(int64 chain_first_node, int64 insertion_node);
  // Relocates the subtrip ending at chain_first_node. It must be a delivery.
  bool RelocateSubTripFromDelivery(int64 chain_last_node, int64 insertion_node);
  std::vector<bool> is_pickup_node_;
  std::vector<bool> is_delivery_node_;
  std::vector<int> pair_of_node_;
  // Represents the set of pairs that have been opened during a call to
  // MakeNeighbor(). This vector must be all false before and after calling
  // RelocateSubTripFromPickup() and RelocateSubTripFromDelivery().
  std::vector<bool> opened_pairs_bitset_;

  std::vector<int64> rejected_nodes_;
  std::vector<int64> subtrip_nodes_;
};

class ExchangeSubtrip : public PathWithPreviousNodesOperator {
 public:
  ExchangeSubtrip(const std::vector<IntVar*>& vars,
                  const std::vector<IntVar*>& secondary_vars,
                  std::function<int(int64)> start_empty_path_class,
                  const RoutingIndexPairs& pairs);

  std::string DebugString() const override { return "ExchangeSubtrip"; }
  bool MakeNeighbor() override;

 private:
  // Try to extract a subtrip from base_node (see below) and check that the move
  // will be canonical.
  // Given a pickup/delivery pair, this operator could generate the same move
  // twice, the first time with base_node == pickup, the second time with
  // base_node == delivery. This happens only when no nodes in the subtrip
  // remain in the original path, i.e. when rejects is empty after
  // chain extraction. In that case, we keep only a canonical move out of the
  // two possibilities, the move where base_node is a pickup.
  bool ExtractChainsAndCheckCanonical(int64 base_node,
                                      std::vector<int64>* rejects,
                                      std::vector<int64>* subtrip);
  // Reads the path from base_node forward, collecting subtrip nodes in
  // subtrip and non-subtrip nodes in rejects.
  // Non-subtrip nodes will be unmatched delivery nodes.
  // base_node must be a pickup, and remaining/extracted_nodes must be empty.
  // Returns true if such chains could be extracted.
  bool ExtractChainsFromPickup(int64 base_node, std::vector<int64>* rejects,
                               std::vector<int64>* subtrip);
  // Reads the path from base_node backward, collecting subtrip nodes in
  // subtrip and non-subtrip nodes in rejects.
  // Non-subtrip nodes will be unmatched pickup nodes.
  // base_node must be a delivery, and remaining/extracted_nodes must be empty.
  // Returns true if such chains could be extracted.
  bool ExtractChainsFromDelivery(int64 base_node, std::vector<int64>* rejects,
                                 std::vector<int64>* subtrip);
  void SetPath(const std::vector<int64>& path, int path_id);

  // Precompute some information about nodes.
  std::vector<bool> is_pickup_node_;
  std::vector<bool> is_delivery_node_;
  std::vector<int> pair_of_node_;
  // Represents the set of opened pairs during ExtractChainsFromXXX().
  std::vector<bool> opened_pairs_set_;
  // Keep internal structures under hand to avoid reallocation.
  std::vector<int64> rejects0_;
  std::vector<int64> subtrip0_;
  std::vector<int64> rejects1_;
  std::vector<int64> subtrip1_;
  std::vector<int64> path0_;
  std::vector<int64> path1_;
};

}  // namespace operations_research

#endif  // OR_TOOLS_CONSTRAINT_SOLVER_ROUTING_NEIGHBORHOODS_H_