routing.h

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// 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.

// TODO(user): Add a section on costs (vehicle arc costs, span costs,
//                disjunctions costs).
//

#ifndef OR_TOOLS_CONSTRAINT_SOLVER_ROUTING_H_
#define OR_TOOLS_CONSTRAINT_SOLVER_ROUTING_H_

#include <cstddef>
#include <functional>
#include <memory>
#include <queue>
#include <string>
#include <utility>
#include <vector>

#include "absl/container/flat_hash_map.h"
#include "absl/container/flat_hash_set.h"
#include "absl/hash/hash.h"
#include "absl/time/time.h"
#include "ortools/base/adjustable_priority_queue-inl.h"
#include "ortools/base/adjustable_priority_queue.h"
#include "ortools/base/commandlineflags.h"
#include "ortools/base/hash.h"
#include "ortools/base/int_type_indexed_vector.h"
#include "ortools/base/logging.h"
#include "ortools/base/macros.h"
#include "ortools/constraint_solver/constraint_solver.h"
#include "ortools/constraint_solver/constraint_solveri.h"
#include "ortools/constraint_solver/routing_index_manager.h"
#include "ortools/constraint_solver/routing_parameters.pb.h"
#include "ortools/constraint_solver/routing_types.h"
#include "ortools/glop/lp_solver.h"
#include "ortools/glop/parameters.pb.h"
#include "ortools/graph/graph.h"
#include "ortools/lp_data/lp_data.h"
#include "ortools/lp_data/lp_types.h"
#include "ortools/sat/theta_tree.h"
#include "ortools/util/range_query_function.h"
#include "ortools/util/sorted_interval_list.h"

namespace operations_research {

class GlobalDimensionCumulOptimizer;
class IntVarFilteredDecisionBuilder;
class LocalDimensionCumulOptimizer;
class LocalSearchOperator;
class RoutingDimension;
#ifndef SWIG
using util::ReverseArcListGraph;
class SweepArranger;
#endif
struct SweepIndex;

class RoutingModel {
 public:
  enum Status {
    ROUTING_NOT_SOLVED,
    ROUTING_SUCCESS,
    ROUTING_FAIL,
    ROUTING_FAIL_TIMEOUT,
    ROUTING_INVALID
  };

  enum PickupAndDeliveryPolicy {
    PICKUP_AND_DELIVERY_NO_ORDER,
    PICKUP_AND_DELIVERY_LIFO,
    PICKUP_AND_DELIVERY_FIFO
  };
  typedef RoutingCostClassIndex CostClassIndex;
  typedef RoutingDimensionIndex DimensionIndex;
  typedef RoutingDisjunctionIndex DisjunctionIndex;
  typedef RoutingVehicleClassIndex VehicleClassIndex;
  typedef RoutingTransitCallback1 TransitCallback1;
  typedef RoutingTransitCallback2 TransitCallback2;

// TODO(user): Remove all SWIG guards by adding the @ignore in .i.
#if !defined(SWIG)
  typedef RoutingIndexPair IndexPair;
  typedef RoutingIndexPairs IndexPairs;
#endif  // SWIG

#if !defined(SWIG)
  struct StateDependentTransit {
    RangeIntToIntFunction* transit;                   
    RangeMinMaxIndexFunction* transit_plus_identity;  
  };
  typedef std::function<StateDependentTransit(int64, int64)>
      VariableIndexEvaluator2;
#endif  // SWIG

#if !defined(SWIG)
  struct CostClass {
    int evaluator_index = 0;


    struct DimensionCost {
      int64 transit_evaluator_class;
      int64 cost_coefficient;
      const RoutingDimension* dimension;
      bool operator<(const DimensionCost& cost) const {
        if (transit_evaluator_class != cost.transit_evaluator_class) {
          return transit_evaluator_class < cost.transit_evaluator_class;
        }
        return cost_coefficient < cost.cost_coefficient;
      }
    };
    std::vector<DimensionCost>
        dimension_transit_evaluator_class_and_cost_coefficient;

    explicit CostClass(int evaluator_index)
        : evaluator_index(evaluator_index) {}

    static bool LessThan(const CostClass& a, const CostClass& b) {
      if (a.evaluator_index != b.evaluator_index) {
        return a.evaluator_index < b.evaluator_index;
      }
      return a.dimension_transit_evaluator_class_and_cost_coefficient <
             b.dimension_transit_evaluator_class_and_cost_coefficient;
    }
  };

  struct VehicleClass {
    CostClassIndex cost_class_index;
    int64 fixed_cost;
    // TODO(user): Find equivalent start/end nodes wrt dimensions and
    // callbacks.
    int start_equivalence_class;
    int end_equivalence_class;
    gtl::ITIVector<DimensionIndex, int64> dimension_start_cumuls_min;
    gtl::ITIVector<DimensionIndex, int64> dimension_start_cumuls_max;
    gtl::ITIVector<DimensionIndex, int64> dimension_end_cumuls_min;
    gtl::ITIVector<DimensionIndex, int64> dimension_end_cumuls_max;
    gtl::ITIVector<DimensionIndex, int64> dimension_capacities;
    gtl::ITIVector<DimensionIndex, int64> dimension_evaluator_classes;
    uint64 unvisitable_nodes_fprint;

    static bool LessThan(const VehicleClass& a, const VehicleClass& b);
  };
#endif  // defined(SWIG)

  static const int64 kNoPenalty;

  static const DisjunctionIndex kNoDisjunction;

  static const DimensionIndex kNoDimension;

  explicit RoutingModel(const RoutingIndexManager& index_manager);
  RoutingModel(const RoutingIndexManager& index_manager,
               const RoutingModelParameters& parameters);
  ~RoutingModel();

  int RegisterUnaryTransitCallback(TransitCallback1 callback);
  int RegisterPositiveUnaryTransitCallback(TransitCallback1 callback);
  int RegisterTransitCallback(TransitCallback2 callback);
  int RegisterPositiveTransitCallback(TransitCallback2 callback);
  int RegisterStateDependentTransitCallback(VariableIndexEvaluator2 callback);
  const TransitCallback2& TransitCallback(int callback_index) const {
    CHECK_LT(callback_index, transit_evaluators_.size());
    return transit_evaluators_[callback_index];
  }
  const TransitCallback1& UnaryTransitCallbackOrNull(int callback_index) const {
    CHECK_LT(callback_index, unary_transit_evaluators_.size());
    return unary_transit_evaluators_[callback_index];
  }
  const VariableIndexEvaluator2& StateDependentTransitCallback(
      int callback_index) const {
    CHECK_LT(callback_index, state_dependent_transit_evaluators_.size());
    return state_dependent_transit_evaluators_[callback_index];
  }



  bool AddDimension(int evaluator_index, int64 slack_max, int64 capacity,
                    bool fix_start_cumul_to_zero, const std::string& name);
  bool AddDimensionWithVehicleTransits(
      const std::vector<int>& evaluator_indices, int64 slack_max,
      int64 capacity, bool fix_start_cumul_to_zero, const std::string& name);
  bool AddDimensionWithVehicleCapacity(int evaluator_index, int64 slack_max,
                                       std::vector<int64> vehicle_capacities,
                                       bool fix_start_cumul_to_zero,
                                       const std::string& name);
  bool AddDimensionWithVehicleTransitAndCapacity(
      const std::vector<int>& evaluator_indices, int64 slack_max,
      std::vector<int64> vehicle_capacities, bool fix_start_cumul_to_zero,
      const std::string& name);
  bool AddConstantDimensionWithSlack(int64 value, int64 capacity,
                                     int64 slack_max,
                                     bool fix_start_cumul_to_zero,
                                     const std::string& name);
  bool AddConstantDimension(int64 value, int64 capacity,
                            bool fix_start_cumul_to_zero,
                            const std::string& name) {
    return AddConstantDimensionWithSlack(value, capacity, 0,
                                         fix_start_cumul_to_zero, name);
  }
  bool AddVectorDimension(std::vector<int64> values, int64 capacity,
                          bool fix_start_cumul_to_zero,
                          const std::string& name);
  bool AddMatrixDimension(std::vector<std::vector<int64>> values,
                          int64 capacity, bool fix_start_cumul_to_zero,
                          const std::string& name);
  bool AddDimensionDependentDimensionWithVehicleCapacity(
      const std::vector<int>& pure_transits,
      const std::vector<int>& dependent_transits,
      const RoutingDimension* base_dimension, int64 slack_max,
      std::vector<int64> vehicle_capacities, bool fix_start_cumul_to_zero,
      const std::string& name) {
    return AddDimensionDependentDimensionWithVehicleCapacityInternal(
        pure_transits, dependent_transits, base_dimension, slack_max,
        std::move(vehicle_capacities), fix_start_cumul_to_zero, name);
  }
  bool AddDimensionDependentDimensionWithVehicleCapacity(
      const std::vector<int>& transits, const RoutingDimension* base_dimension,
      int64 slack_max, std::vector<int64> vehicle_capacities,
      bool fix_start_cumul_to_zero, const std::string& name);
  bool AddDimensionDependentDimensionWithVehicleCapacity(
      int transit, const RoutingDimension* base_dimension, int64 slack_max,
      int64 vehicle_capacity, bool fix_start_cumul_to_zero,
      const std::string& name);
  bool AddDimensionDependentDimensionWithVehicleCapacity(
      int pure_transit, int dependent_transit,
      const RoutingDimension* base_dimension, int64 slack_max,
      int64 vehicle_capacity, bool fix_start_cumul_to_zero,
      const std::string& name);

  static RoutingModel::StateDependentTransit MakeStateDependentTransit(
      const std::function<int64(int64)>& f, int64 domain_start,
      int64 domain_end);

  Constraint* MakePathSpansAndTotalSlacks(const RoutingDimension* dimension,
                                          std::vector<IntVar*> spans,
                                          std::vector<IntVar*> total_slacks);

  // TODO(user): rename.
  std::vector<::std::string> GetAllDimensionNames() const;
  const std::vector<RoutingDimension*>& GetDimensions() const {
    return dimensions_.get();
  }
  std::vector<RoutingDimension*> GetDimensionsWithSoftOrSpanCosts() const;
  // clang-format off
  const std::vector<std::unique_ptr<GlobalDimensionCumulOptimizer> >&
  GetGlobalDimensionCumulOptimizers() const {
    return global_dimension_optimizers_;
  }
  const std::vector<std::unique_ptr<LocalDimensionCumulOptimizer> >&
  GetLocalDimensionCumulOptimizers() const {
    return local_dimension_optimizers_;
  }
  // clang-format on

  GlobalDimensionCumulOptimizer* GetMutableGlobalCumulOptimizer(
      const RoutingDimension& dimension) const;
  LocalDimensionCumulOptimizer* GetMutableLocalCumulOptimizer(
      const RoutingDimension& dimension) const;

  bool HasDimension(const std::string& dimension_name) const;
  const RoutingDimension& GetDimensionOrDie(
      const std::string& dimension_name) const;
  RoutingDimension* GetMutableDimension(
      const std::string& dimension_name) const;
  void SetPrimaryConstrainedDimension(const std::string& dimension_name) {
    DCHECK(dimension_name.empty() || HasDimension(dimension_name));
    primary_constrained_dimension_ = dimension_name;
  }
  const std::string& GetPrimaryConstrainedDimension() const {
    return primary_constrained_dimension_;
  }
  DisjunctionIndex AddDisjunction(const std::vector<int64>& indices,
                                  int64 penalty = kNoPenalty,
                                  int64 max_cardinality = 1);
  const std::vector<DisjunctionIndex>& GetDisjunctionIndices(
      int64 index) const {
    return index_to_disjunctions_[index];
  }
  template <typename F>
  void ForEachNodeInDisjunctionWithMaxCardinalityFromIndex(
      int64 index, int64 max_cardinality, F f) const {
    for (const DisjunctionIndex disjunction : GetDisjunctionIndices(index)) {
      if (disjunctions_[disjunction].value.max_cardinality == max_cardinality) {
        for (const int64 d_index : disjunctions_[disjunction].indices) {
          f(d_index);
        }
      }
    }
  }
#if !defined(SWIGPYTHON)
  const std::vector<int64>& GetDisjunctionIndices(
      DisjunctionIndex index) const {
    return disjunctions_[index].indices;
  }
#endif  // !defined(SWIGPYTHON)
  int64 GetDisjunctionPenalty(DisjunctionIndex index) const {
    return disjunctions_[index].value.penalty;
  }
  int64 GetDisjunctionMaxCardinality(DisjunctionIndex index) const {
    return disjunctions_[index].value.max_cardinality;
  }
  int GetNumberOfDisjunctions() const { return disjunctions_.size(); }
  std::vector<std::pair<int64, int64>> GetPerfectBinaryDisjunctions() const;
  void IgnoreDisjunctionsAlreadyForcedToZero();

  void AddSoftSameVehicleConstraint(const std::vector<int64>& indices,
                                    int64 cost);

  void SetAllowedVehiclesForIndex(const std::vector<int>& vehicles,
                                  int64 index);

  bool IsVehicleAllowedForIndex(int vehicle, int64 index) {
    return allowed_vehicles_[index].empty() ||
           allowed_vehicles_[index].find(vehicle) !=
               allowed_vehicles_[index].end();
  }

  // TODO(user): Remove this when model introspection detects linked nodes.
  void AddPickupAndDelivery(int64 pickup, int64 delivery);
  void AddPickupAndDeliverySets(DisjunctionIndex pickup_disjunction,
                                DisjunctionIndex delivery_disjunction);
  // clang-format off
  const std::vector<std::pair<int, int> >&
  GetPickupIndexPairs(int64 node_index) const;
  const std::vector<std::pair<int, int> >&
      GetDeliveryIndexPairs(int64 node_index) const;
  // clang-format on

  void SetPickupAndDeliveryPolicyOfAllVehicles(PickupAndDeliveryPolicy policy);
  void SetPickupAndDeliveryPolicyOfVehicle(PickupAndDeliveryPolicy policy,
                                           int vehicle);
  PickupAndDeliveryPolicy GetPickupAndDeliveryPolicyOfVehicle(
      int vehicle) const;

  int GetNumOfSingletonNodes() const;

#ifndef SWIG
  const IndexPairs& GetPickupAndDeliveryPairs() const {
    return pickup_delivery_pairs_;
  }
  const std::vector<std::pair<DisjunctionIndex, DisjunctionIndex>>&
  GetPickupAndDeliveryDisjunctions() const {
    return pickup_delivery_disjunctions_;
  }
#endif  // SWIG
  // TODO(user): Support multiple visit types per node?
  void SetVisitType(int64 index, int type);
  int GetVisitType(int64 index) const;
  // TODO(user): Reconsider the logic and potentially remove the need to
  void CloseVisitTypes();
  int GetNumberOfVisitTypes() const { return num_visit_types_; }
  void AddHardTypeIncompatibility(int type1, int type2);
  void AddTemporalTypeIncompatibility(int type1, int type2);
  const absl::flat_hash_set<int>& GetHardTypeIncompatibilitiesOfType(
      int type) const;
  const absl::flat_hash_set<int>& GetTemporalTypeIncompatibilitiesOfType(
      int type) const;
  bool HasHardTypeIncompatibilities() const {
    return has_hard_type_incompatibilities_;
  }
  bool HasTemporalTypeIncompatibilities() const {
    return has_temporal_type_incompatibilities_;
  }
  void AddSameVehicleRequiredTypeAlternatives(
      int dependent_type, absl::flat_hash_set<int> required_type_alternatives);
  void AddTemporalRequiredTypeAlternatives(
      int dependent_type, absl::flat_hash_set<int> required_type_alternatives);
  // clang-format off
  const std::vector<absl::flat_hash_set<int> >&
      GetSameVehicleRequiredTypeAlternativesOfType(int type) const;
  const std::vector<absl::flat_hash_set<int> >&
      GetTemporalRequiredTypeAlternativesOfType(int type) const;
  // clang-format on
  bool HasSameVehicleTypeRequirements() const {
    return has_same_vehicle_type_requirements_;
  }
  bool HasTemporalTypeRequirements() const {
    return has_temporal_type_requirements_;
  }

  bool HasTypeRegulations() const {
    return HasTemporalTypeIncompatibilities() ||
           HasHardTypeIncompatibilities() || HasSameVehicleTypeRequirements() ||
           HasTemporalTypeRequirements();
  }

  int64 UnperformedPenalty(int64 var_index) const;
  int64 UnperformedPenaltyOrValue(int64 default_value, int64 var_index) const;
  int64 GetDepot() const;

  void SetArcCostEvaluatorOfAllVehicles(int evaluator_index);
  void SetArcCostEvaluatorOfVehicle(int evaluator_index, int vehicle);
  void SetFixedCostOfAllVehicles(int64 cost);
  void SetFixedCostOfVehicle(int64 cost, int vehicle);
  int64 GetFixedCostOfVehicle(int vehicle) const;

  void SetAmortizedCostFactorsOfAllVehicles(int64 linear_cost_factor,
                                            int64 quadratic_cost_factor);
  void SetAmortizedCostFactorsOfVehicle(int64 linear_cost_factor,
                                        int64 quadratic_cost_factor,
                                        int vehicle);

  const std::vector<int64>& GetAmortizedLinearCostFactorOfVehicles() const {
    return linear_cost_factor_of_vehicle_;
  }
  const std::vector<int64>& GetAmortizedQuadraticCostFactorOfVehicles() const {
    return quadratic_cost_factor_of_vehicle_;
  }

  void ConsiderEmptyRouteCostsForVehicle(bool consider_costs, int vehicle) {
    DCHECK_LT(vehicle, vehicles_);
    consider_empty_route_costs_[vehicle] = consider_costs;
  }

  bool AreEmptyRouteCostsConsideredForVehicle(int vehicle) const {
    DCHECK_LT(vehicle, vehicles_);
    return consider_empty_route_costs_[vehicle];
  }

#ifndef SWIG
  const Solver::IndexEvaluator2& first_solution_evaluator() const {
    return first_solution_evaluator_;
  }
#endif
  void SetFirstSolutionEvaluator(Solver::IndexEvaluator2 evaluator) {
    first_solution_evaluator_ = std::move(evaluator);
  }
  void AddLocalSearchOperator(LocalSearchOperator* ls_operator);
  void AddSearchMonitor(SearchMonitor* const monitor);
  void AddAtSolutionCallback(std::function<void()> callback);
  void AddVariableMinimizedByFinalizer(IntVar* var);
  void AddVariableMaximizedByFinalizer(IntVar* var);
  void AddWeightedVariableMinimizedByFinalizer(IntVar* var, int64 cost);
  void AddVariableTargetToFinalizer(IntVar* var, int64 target);
  void CloseModel();
  void CloseModelWithParameters(
      const RoutingSearchParameters& search_parameters);
  const Assignment* Solve(const Assignment* assignment = nullptr);
  const Assignment* SolveWithParameters(
      const RoutingSearchParameters& search_parameters,
      std::vector<const Assignment*>* solutions = nullptr);
  const Assignment* SolveFromAssignmentWithParameters(
      const Assignment* assignment,
      const RoutingSearchParameters& search_parameters,
      std::vector<const Assignment*>* solutions = nullptr);
  void SetAssignmentFromOtherModelAssignment(
      Assignment* target_assignment, const RoutingModel* source_model,
      const Assignment* source_assignment);
  // TODO(user): Add support for non-homogeneous costs and disjunctions.
  int64 ComputeLowerBound();
  Status status() const { return status_; }
  IntVar* ApplyLocks(const std::vector<int64>& locks);
  bool ApplyLocksToAllVehicles(const std::vector<std::vector<int64>>& locks,
                               bool close_routes);
  const Assignment* const PreAssignment() const { return preassignment_; }
  Assignment* MutablePreAssignment() { return preassignment_; }
  bool WriteAssignment(const std::string& file_name) const;
  Assignment* ReadAssignment(const std::string& file_name);
  Assignment* RestoreAssignment(const Assignment& solution);
  Assignment* ReadAssignmentFromRoutes(
      const std::vector<std::vector<int64>>& routes,
      bool ignore_inactive_indices);
  bool RoutesToAssignment(const std::vector<std::vector<int64>>& routes,
                          bool ignore_inactive_indices, bool close_routes,
                          Assignment* const assignment) const;
  void AssignmentToRoutes(const Assignment& assignment,
                          std::vector<std::vector<int64>>* const routes) const;
  Assignment* CompactAssignment(const Assignment& assignment) const;
  Assignment* CompactAndCheckAssignment(const Assignment& assignment) const;
  void AddToAssignment(IntVar* const var);
  void AddIntervalToAssignment(IntervalVar* const interval);
  const Assignment* PackCumulsOfOptimizerDimensionsFromAssignment(
      const Assignment* original_assignment, absl::Duration duration_limit);
#ifndef SWIG
  // TODO(user): Revisit if coordinates are added to the RoutingModel class.
  void SetSweepArranger(SweepArranger* sweep_arranger) {
    sweep_arranger_.reset(sweep_arranger);
  }
  SweepArranger* sweep_arranger() const { return sweep_arranger_.get(); }
#endif
  void AddLocalSearchFilter(LocalSearchFilter* filter) {
    CHECK(filter != nullptr);
    if (closed_) {
      LOG(WARNING) << "Model is closed, filter addition will be ignored.";
    }
    extra_filters_.push_back(filter);
  }

  int64 Start(int vehicle) const { return starts_[vehicle]; }
  int64 End(int vehicle) const { return ends_[vehicle]; }
  bool IsStart(int64 index) const;
  bool IsEnd(int64 index) const { return index >= Size(); }
  int VehicleIndex(int index) const { return index_to_vehicle_[index]; }
  int64 Next(const Assignment& assignment, int64 index) const;
  bool IsVehicleUsed(const Assignment& assignment, int vehicle) const;

#if !defined(SWIGPYTHON)
  const std::vector<IntVar*>& Nexts() const { return nexts_; }
  const std::vector<IntVar*>& VehicleVars() const { return vehicle_vars_; }
#endif  
  IntVar* NextVar(int64 index) const { return nexts_[index]; }
  IntVar* ActiveVar(int64 index) const { return active_[index]; }
  IntVar* VehicleCostsConsideredVar(int vehicle) const {
    return vehicle_costs_considered_[vehicle];
  }
  IntVar* VehicleVar(int64 index) const { return vehicle_vars_[index]; }
  IntVar* CostVar() const { return cost_; }

  int64 GetArcCostForVehicle(int64 from_index, int64 to_index,
                             int64 vehicle) const;
  bool CostsAreHomogeneousAcrossVehicles() const {
    return costs_are_homogeneous_across_vehicles_;
  }
  int64 GetHomogeneousCost(int64 from_index, int64 to_index) const {
    return GetArcCostForVehicle(from_index, to_index, /*vehicle=*/0);
  }
  int64 GetArcCostForFirstSolution(int64 from_index, int64 to_index) const;
  int64 GetArcCostForClass(int64 from_index, int64 to_index,
                           int64 /*CostClassIndex*/ cost_class_index) const;
  CostClassIndex GetCostClassIndexOfVehicle(int64 vehicle) const {
    DCHECK(closed_);
    return cost_class_index_of_vehicle_[vehicle];
  }
  bool HasVehicleWithCostClassIndex(CostClassIndex cost_class_index) const {
    DCHECK(closed_);
    if (cost_class_index == kCostClassIndexOfZeroCost) {
      return has_vehicle_with_zero_cost_class_;
    }
    return cost_class_index < cost_classes_.size();
  }
  int GetCostClassesCount() const { return cost_classes_.size(); }
  int GetNonZeroCostClassesCount() const {
    return std::max(0, GetCostClassesCount() - 1);
  }
  VehicleClassIndex GetVehicleClassIndexOfVehicle(int64 vehicle) const {
    DCHECK(closed_);
    return vehicle_class_index_of_vehicle_[vehicle];
  }
  int GetVehicleClassesCount() const { return vehicle_classes_.size(); }
  const std::vector<int>& GetSameVehicleIndicesOfIndex(int node) const {
    DCHECK(closed_);
    return same_vehicle_groups_[same_vehicle_group_[node]];
  }
  bool ArcIsMoreConstrainedThanArc(int64 from, int64 to1, int64 to2);
  std::string DebugOutputAssignment(
      const Assignment& solution_assignment,
      const std::string& dimension_to_print) const;

  Solver* solver() const { return solver_.get(); }

  bool CheckLimit() {
    DCHECK(limit_ != nullptr);
    return limit_->Check();
  }

  absl::Duration RemainingTime() const {
    DCHECK(limit_ != nullptr);
    return limit_->AbsoluteSolverDeadline() - solver_->Now();
  }

  int nodes() const { return nodes_; }
  int vehicles() const { return vehicles_; }
  int64 Size() const { return nodes_ + vehicles_ - start_end_count_; }

  int64 GetNumberOfDecisionsInFirstSolution(
      const RoutingSearchParameters& search_parameters) const;
  int64 GetNumberOfRejectsInFirstSolution(
      const RoutingSearchParameters& search_parameters) const;

  bool IsMatchingModel() const;

#ifndef SWIG
  using GetTabuVarsCallback =
      std::function<std::vector<operations_research::IntVar*>(RoutingModel*)>;

  void SetTabuVarsCallback(GetTabuVarsCallback tabu_var_callback);
#endif  // SWIG

  // TODO(user): Find a way to test and restrict the access at the same time.
  DecisionBuilder* MakeGuidedSlackFinalizer(
      const RoutingDimension* dimension,
      std::function<int64(int64)> initializer);
#ifndef SWIG
  // TODO(user): MakeGreedyDescentLSOperator is too general for routing.h.
  static std::unique_ptr<LocalSearchOperator> MakeGreedyDescentLSOperator(
      std::vector<IntVar*> variables);
#endif  
  DecisionBuilder* MakeSelfDependentDimensionFinalizer(
      const RoutingDimension* dimension);

 private:
  enum RoutingLocalSearchOperator {
    RELOCATE = 0,
    RELOCATE_PAIR,
    LIGHT_RELOCATE_PAIR,
    RELOCATE_NEIGHBORS,
    EXCHANGE,
    EXCHANGE_PAIR,
    CROSS,
    CROSS_EXCHANGE,
    TWO_OPT,
    OR_OPT,
    RELOCATE_EXPENSIVE_CHAIN,
    LIN_KERNIGHAN,
    TSP_OPT,
    MAKE_ACTIVE,
    RELOCATE_AND_MAKE_ACTIVE,
    MAKE_ACTIVE_AND_RELOCATE,
    MAKE_INACTIVE,
    MAKE_CHAIN_INACTIVE,
    SWAP_ACTIVE,
    EXTENDED_SWAP_ACTIVE,
    NODE_PAIR_SWAP,
    PATH_LNS,
    FULL_PATH_LNS,
    TSP_LNS,
    INACTIVE_LNS,
    EXCHANGE_RELOCATE_PAIR,
    RELOCATE_SUBTRIP,
    EXCHANGE_SUBTRIP,
    LOCAL_SEARCH_OPERATOR_COUNTER
  };

  template <typename T>
  struct ValuedNodes {
    std::vector<int64> indices;
    T value;
  };
  struct DisjunctionValues {
    int64 penalty;
    int64 max_cardinality;
  };
  typedef ValuedNodes<DisjunctionValues> Disjunction;

  struct CostCacheElement {
    int index;
    CostClassIndex cost_class_index;
    int64 cost;
  };

  void Initialize();
  void AddNoCycleConstraintInternal();
  bool AddDimensionWithCapacityInternal(
      const std::vector<int>& evaluator_indices, int64 slack_max,
      std::vector<int64> vehicle_capacities, bool fix_start_cumul_to_zero,
      const std::string& name);
  bool AddDimensionDependentDimensionWithVehicleCapacityInternal(
      const std::vector<int>& pure_transits,
      const std::vector<int>& dependent_transits,
      const RoutingDimension* base_dimension, int64 slack_max,
      std::vector<int64> vehicle_capacities, bool fix_start_cumul_to_zero,
      const std::string& name);
  bool InitializeDimensionInternal(
      const std::vector<int>& evaluator_indices,
      const std::vector<int>& state_dependent_evaluator_indices,
      int64 slack_max, bool fix_start_cumul_to_zero,
      RoutingDimension* dimension);
  DimensionIndex GetDimensionIndex(const std::string& dimension_name) const;

  void StoreDimensionCumulOptimizers();

  void ComputeCostClasses(const RoutingSearchParameters& parameters);
  void ComputeVehicleClasses();
  int64 GetArcCostForClassInternal(int64 from_index, int64 to_index,
                                   CostClassIndex cost_class_index) const;
  void AppendHomogeneousArcCosts(const RoutingSearchParameters& parameters,
                                 int node_index,
                                 std::vector<IntVar*>* cost_elements);
  void AppendArcCosts(const RoutingSearchParameters& parameters, int node_index,
                      std::vector<IntVar*>* cost_elements);
  Assignment* DoRestoreAssignment();
  static const CostClassIndex kCostClassIndexOfZeroCost;
  int64 SafeGetCostClassInt64OfVehicle(int64 vehicle) const {
    DCHECK_LT(0, vehicles_);
    return (vehicle >= 0 ? GetCostClassIndexOfVehicle(vehicle)
                         : kCostClassIndexOfZeroCost)
        .value();
  }
  int64 GetDimensionTransitCostSum(int64 i, int64 j,
                                   const CostClass& cost_class) const;
  IntVar* CreateDisjunction(DisjunctionIndex disjunction);
  void AddPickupAndDeliverySetsInternal(const std::vector<int64>& pickups,
                                        const std::vector<int64>& deliveries);
  IntVar* CreateSameVehicleCost(int vehicle_index);
  int FindNextActive(int index, const std::vector<int64>& indices) const;

  bool RouteCanBeUsedByVehicle(const Assignment& assignment, int start_index,
                               int vehicle) const;
  bool ReplaceUnusedVehicle(int unused_vehicle, int active_vehicle,
                            Assignment* compact_assignment) const;

  void QuietCloseModel();
  void QuietCloseModelWithParameters(
      const RoutingSearchParameters& parameters) {
    if (!closed_) {
      CloseModelWithParameters(parameters);
    }
  }

  bool SolveMatchingModel(Assignment* assignment);
#ifndef SWIG
  bool AppendAssignmentIfFeasible(
      const Assignment& assignment,
      std::vector<std::unique_ptr<Assignment>>* assignments);
#endif
  void LogSolution(const RoutingSearchParameters& parameters,
                   const std::string& description, int64 solution_cost,
                   int64 start_time_ms);
  Assignment* CompactAssignmentInternal(const Assignment& assignment,
                                        bool check_compact_assignment) const;
  std::string FindErrorInSearchParametersForModel(
      const RoutingSearchParameters& search_parameters) const;
  void SetupSearch(const RoutingSearchParameters& search_parameters);
  // TODO(user): Document each auxiliary method.
  Assignment* GetOrCreateAssignment();
  Assignment* GetOrCreateTmpAssignment();
  RegularLimit* GetOrCreateLimit();
  RegularLimit* GetOrCreateLocalSearchLimit();
  RegularLimit* GetOrCreateLargeNeighborhoodSearchLimit();
  RegularLimit* GetOrCreateFirstSolutionLargeNeighborhoodSearchLimit();
  LocalSearchOperator* CreateInsertionOperator();
  LocalSearchOperator* CreateMakeInactiveOperator();
  void CreateNeighborhoodOperators(const RoutingSearchParameters& parameters);
  LocalSearchOperator* GetNeighborhoodOperators(
      const RoutingSearchParameters& search_parameters) const;
  const std::vector<LocalSearchFilter*>& GetOrCreateLocalSearchFilters();
  const std::vector<LocalSearchFilter*>& GetOrCreateFeasibilityFilters();
  DecisionBuilder* CreateSolutionFinalizer(SearchLimit* lns_limit);
  DecisionBuilder* CreateFinalizerForMinimizedAndMaximizedVariables();
  void CreateFirstSolutionDecisionBuilders(
      const RoutingSearchParameters& search_parameters);
  DecisionBuilder* GetFirstSolutionDecisionBuilder(
      const RoutingSearchParameters& search_parameters) const;
  IntVarFilteredDecisionBuilder* GetFilteredFirstSolutionDecisionBuilderOrNull(
      const RoutingSearchParameters& parameters) const;
  LocalSearchPhaseParameters* CreateLocalSearchParameters(
      const RoutingSearchParameters& search_parameters);
  DecisionBuilder* CreateLocalSearchDecisionBuilder(
      const RoutingSearchParameters& search_parameters);
  void SetupDecisionBuilders(const RoutingSearchParameters& search_parameters);
  void SetupMetaheuristics(const RoutingSearchParameters& search_parameters);
  void SetupAssignmentCollector(
      const RoutingSearchParameters& search_parameters);
  void SetupTrace(const RoutingSearchParameters& search_parameters);
  void SetupSearchMonitors(const RoutingSearchParameters& search_parameters);
  bool UsesLightPropagation(
      const RoutingSearchParameters& search_parameters) const;
  GetTabuVarsCallback tabu_var_callback_;

  int GetVehicleStartClass(int64 start) const;

  void InitSameVehicleGroups(int number_of_groups) {
    same_vehicle_group_.assign(Size(), 0);
    same_vehicle_groups_.assign(number_of_groups, {});
  }
  void SetSameVehicleGroup(int index, int group) {
    same_vehicle_group_[index] = group;
    same_vehicle_groups_[group].push_back(index);
  }

  std::unique_ptr<Solver> solver_;
  int nodes_;
  int vehicles_;
  Constraint* no_cycle_constraint_ = nullptr;
  std::vector<IntVar*> nexts_;
  std::vector<IntVar*> vehicle_vars_;
  std::vector<IntVar*> active_;
  std::vector<IntVar*> vehicle_costs_considered_;
  std::vector<IntVar*> is_bound_to_end_;
  mutable RevSwitch is_bound_to_end_ct_added_;
  absl::flat_hash_map<std::string, DimensionIndex> dimension_name_to_index_;
  gtl::ITIVector<DimensionIndex, RoutingDimension*> dimensions_;
  // clang-format off
  std::vector<std::unique_ptr<GlobalDimensionCumulOptimizer> >
      global_dimension_optimizers_;
  gtl::ITIVector<DimensionIndex, int> global_optimizer_index_;
  std::vector<std::unique_ptr<LocalDimensionCumulOptimizer> >
      local_dimension_optimizers_;
  // clang-format off
  gtl::ITIVector<DimensionIndex, int> local_optimizer_index_;
  std::string primary_constrained_dimension_;
  IntVar* cost_ = nullptr;
  std::vector<int> vehicle_to_transit_cost_;
  std::vector<int64> fixed_cost_of_vehicle_;
  std::vector<CostClassIndex> cost_class_index_of_vehicle_;
  bool has_vehicle_with_zero_cost_class_;
  std::vector<int64> linear_cost_factor_of_vehicle_;
  std::vector<int64> quadratic_cost_factor_of_vehicle_;
  bool vehicle_amortized_cost_factors_set_;
  std::vector<bool> consider_empty_route_costs_;
#ifndef SWIG
  gtl::ITIVector<CostClassIndex, CostClass> cost_classes_;
#endif  // SWIG
  bool costs_are_homogeneous_across_vehicles_;
  bool cache_callbacks_;
  mutable std::vector<CostCacheElement> cost_cache_;  
  std::vector<VehicleClassIndex> vehicle_class_index_of_vehicle_;
#ifndef SWIG
  gtl::ITIVector<VehicleClassIndex, VehicleClass> vehicle_classes_;
#endif  // SWIG
  std::function<int(int64)> vehicle_start_class_callback_;
  gtl::ITIVector<DisjunctionIndex, Disjunction> disjunctions_;
  std::vector<std::vector<DisjunctionIndex> > index_to_disjunctions_;
  std::vector<ValuedNodes<int64> > same_vehicle_costs_;
#ifndef SWIG
  std::vector<std::unordered_set<int>> allowed_vehicles_;
#endif  // SWIG
  IndexPairs pickup_delivery_pairs_;
  std::vector<std::pair<DisjunctionIndex, DisjunctionIndex> >
      pickup_delivery_disjunctions_;
  // clang-format off
  // If node_index is a pickup, index_to_pickup_index_pairs_[node_index] is the
  // vector of pairs {pair_index, pickup_index} such that
  // (pickup_delivery_pairs_[pair_index].first)[pickup_index] == node_index
  std::vector<std::vector<std::pair<int, int> > > index_to_pickup_index_pairs_;
  // Same as above for deliveries.
  std::vector<std::vector<std::pair<int, int> > >
      index_to_delivery_index_pairs_;
  // clang-format on
  std::vector<PickupAndDeliveryPolicy> vehicle_pickup_delivery_policy_;
  // Same vehicle group to which a node belongs.
  std::vector<int> same_vehicle_group_;
  // Same vehicle node groups.
  std::vector<std::vector<int>> same_vehicle_groups_;
  // Node visit types
  // Variable index to visit type index.
  std::vector<int> index_to_visit_type_;
  // clang-format off
  std::vector<absl::flat_hash_set<int> >
      hard_incompatible_types_per_type_index_;
  bool has_hard_type_incompatibilities_;
  std::vector<absl::flat_hash_set<int> >
      temporal_incompatible_types_per_type_index_;
  bool has_temporal_type_incompatibilities_;

  std::vector<std::vector<absl::flat_hash_set<int> > >
      same_vehicle_required_type_alternatives_per_type_index_;
  bool has_same_vehicle_type_requirements_;
  std::vector<std::vector<absl::flat_hash_set<int> > >
      temporal_required_type_alternatives_per_type_index_;
  bool has_temporal_type_requirements_;
  absl::flat_hash_set<int> trivially_infeasible_visit_types_;
  // clang-format on
  int num_visit_types_;
  // Two indices are equivalent if they correspond to the same node (as given
  // to the constructors taking a RoutingIndexManager).
  std::vector<int> index_to_equivalence_class_;
  std::vector<int> index_to_vehicle_;
  std::vector<int64> starts_;
  std::vector<int64> ends_;
  // TODO(user): b/62478706 Once the port is done, this shouldn't be needed
  //                  anymore.
  RoutingIndexManager manager_;
  int start_end_count_;
  // Model status
  bool closed_ = false;
  Status status_ = ROUTING_NOT_SOLVED;
  bool enable_deep_serialization_ = true;

  // Search data
  std::vector<DecisionBuilder*> first_solution_decision_builders_;
  std::vector<IntVarFilteredDecisionBuilder*>
      first_solution_filtered_decision_builders_;
  Solver::IndexEvaluator2 first_solution_evaluator_;
  std::vector<LocalSearchOperator*> local_search_operators_;
  std::vector<SearchMonitor*> monitors_;
  SolutionCollector* collect_assignments_ = nullptr;
  SolutionCollector* collect_one_assignment_ = nullptr;
  SolutionCollector* packed_dimensions_assignment_collector_ = nullptr;
  DecisionBuilder* solve_db_ = nullptr;
  DecisionBuilder* improve_db_ = nullptr;
  DecisionBuilder* restore_assignment_ = nullptr;
  DecisionBuilder* restore_tmp_assignment_ = nullptr;
  Assignment* assignment_ = nullptr;
  Assignment* preassignment_ = nullptr;
  Assignment* tmp_assignment_ = nullptr;
  std::vector<IntVar*> extra_vars_;
  std::vector<IntervalVar*> extra_intervals_;
  std::vector<LocalSearchOperator*> extra_operators_;
  std::vector<LocalSearchFilter*> filters_;
  std::vector<LocalSearchFilter*> feasibility_filters_;
  std::vector<LocalSearchFilter*> extra_filters_;
#ifndef SWIG
  std::vector<std::pair<IntVar*, int64>> finalizer_variable_cost_pairs_;
  std::vector<std::pair<IntVar*, int64>> finalizer_variable_target_pairs_;
  absl::flat_hash_map<IntVar*, int> finalizer_variable_cost_index_;
  absl::flat_hash_set<IntVar*> finalizer_variable_target_set_;
  std::unique_ptr<SweepArranger> sweep_arranger_;
#endif

  RegularLimit* limit_ = nullptr;
  RegularLimit* ls_limit_ = nullptr;
  RegularLimit* lns_limit_ = nullptr;
  RegularLimit* first_solution_lns_limit_ = nullptr;

  typedef std::pair<int64, int64> CacheKey;
  typedef absl::flat_hash_map<CacheKey, int64> TransitCallbackCache;
  typedef absl::flat_hash_map<CacheKey, StateDependentTransit>
      StateDependentTransitCallbackCache;

  std::vector<TransitCallback1> unary_transit_evaluators_;
  std::vector<TransitCallback2> transit_evaluators_;
  // The following vector stores a boolean per transit_evaluator_, indicating
  // whether the transits are all positive.
  // is_transit_evaluator_positive_ will be set to true only when registering a
  // callback via RegisterPositiveTransitCallback(), and to false otherwise.
  // The actual positivity of the transit values will only be checked in debug
  // mode, when calling RegisterPositiveTransitCallback().
  // Therefore, RegisterPositiveTransitCallback() should only be called when the
  // transits are known to be positive, as the positivity of a callback will
  // allow some improvements in the solver, but will entail in errors if the
  // transits are falsely assumed positive.
  std::vector<bool> is_transit_evaluator_positive_;
  std::vector<VariableIndexEvaluator2> state_dependent_transit_evaluators_;
  std::vector<std::unique_ptr<StateDependentTransitCallbackCache>>
      state_dependent_transit_evaluators_cache_;

  friend class RoutingDimension;
  friend class RoutingModelInspector;

  DISALLOW_COPY_AND_ASSIGN(RoutingModel);
};

class RoutingModelVisitor : public BaseObject {
 public:
  static const char kLightElement[];
  static const char kLightElement2[];
  static const char kRemoveValues[];
};

#if !defined(SWIG)
class DisjunctivePropagator {
 public:
  struct Tasks {
    int num_chain_tasks = 0;
    std::vector<int64> start_min;
    std::vector<int64> start_max;
    std::vector<int64> duration_min;
    std::vector<int64> duration_max;
    std::vector<int64> end_min;
    std::vector<int64> end_max;
    std::vector<bool> is_preemptible;
    std::vector<const SortedDisjointIntervalList*> forbidden_intervals;
    std::vector<std::pair<int64, int64>> distance_duration;

    void Clear() {
      start_min.clear();
      start_max.clear();
      duration_min.clear();
      duration_max.clear();
      end_min.clear();
      end_max.clear();
      is_preemptible.clear();
      forbidden_intervals.clear();
      distance_duration.clear();
    }
  };

  bool Propagate(Tasks* tasks);

  bool Precedences(Tasks* tasks);
  bool MirrorTasks(Tasks* tasks);
  bool EdgeFinding(Tasks* tasks);
  bool DetectablePrecedencesWithChain(Tasks* tasks);
  bool ForbiddenIntervals(Tasks* tasks);
  bool DistanceDuration(Tasks* tasks);

 private:
  sat::ThetaLambdaTree<int64> theta_lambda_tree_;
  std::vector<int> tasks_by_start_min_;
  std::vector<int> tasks_by_end_max_;
  std::vector<int> event_of_task_;
  std::vector<int> nonchain_tasks_by_start_max_;
};

void AppendTasksFromPath(const std::vector<int64>& path,
                         const std::vector<int64>& min_travels,
                         const std::vector<int64>& max_travels,
                         const std::vector<int64>& pre_travels,
                         const std::vector<int64>& post_travels,
                         const RoutingDimension& dimension,
                         DisjunctivePropagator::Tasks* tasks);
void AppendTasksFromIntervals(const std::vector<IntervalVar*>& intervals,
                              DisjunctivePropagator::Tasks* tasks);
void FillPathEvaluation(const std::vector<int64>& path,
                        const RoutingModel::TransitCallback2& evaluator,
                        std::vector<int64>* values);
#endif  // !defined(SWIG)

class GlobalVehicleBreaksConstraint : public Constraint {
 public:
  explicit GlobalVehicleBreaksConstraint(const RoutingDimension* dimension);

  void Post() override;
  void InitialPropagate() override;

 private:
  void PropagateNode(int node);
  void PropagateVehicle(int vehicle);
  void PropagateMaxBreakDistance(int vehicle);

  const RoutingModel* model_;
  const RoutingDimension* const dimension_;
  std::vector<Demon*> vehicle_demons_;
  std::vector<int64> path_;

  void FillPartialPathOfVehicle(int vehicle);
  void FillPathTravels(const std::vector<int64>& path);

  class TaskTranslator {
   public:
    TaskTranslator(IntVar* start, int64 before_start, int64 after_start)
        : start_(start),
          before_start_(before_start),
          after_start_(after_start) {}
    explicit TaskTranslator(IntervalVar* interval) : interval_(interval) {}
    TaskTranslator() {}

    void SetStartMin(int64 value) {
      if (start_ != nullptr) {
        start_->SetMin(CapAdd(before_start_, value));
      } else if (interval_ != nullptr) {
        interval_->SetStartMin(value);
      }
    }
    void SetStartMax(int64 value) {
      if (start_ != nullptr) {
        start_->SetMax(CapAdd(before_start_, value));
      } else if (interval_ != nullptr) {
        interval_->SetStartMax(value);
      }
    }
    void SetDurationMin(int64 value) {
      if (interval_ != nullptr) {
        interval_->SetDurationMin(value);
      }
    }
    void SetEndMin(int64 value) {
      if (start_ != nullptr) {
        start_->SetMin(CapSub(value, after_start_));
      } else if (interval_ != nullptr) {
        interval_->SetEndMin(value);
      }
    }
    void SetEndMax(int64 value) {
      if (start_ != nullptr) {
        start_->SetMax(CapSub(value, after_start_));
      } else if (interval_ != nullptr) {
        interval_->SetEndMax(value);
      }
    }

   private:
    IntVar* start_ = nullptr;
    int64 before_start_;
    int64 after_start_;
    IntervalVar* interval_ = nullptr;
  };

  std::vector<TaskTranslator> task_translators_;

  DisjunctivePropagator disjunctive_propagator_;
  DisjunctivePropagator::Tasks tasks_;

  std::vector<int64> min_travel_;
  std::vector<int64> max_travel_;
  std::vector<int64> pre_travel_;
  std::vector<int64> post_travel_;
};

class TypeRegulationsChecker {
 public:
  explicit TypeRegulationsChecker(const RoutingModel& model);
  virtual ~TypeRegulationsChecker() {}

  bool CheckVehicle(int vehicle,
                    const std::function<int64(int64)>& next_accessor);

 protected:
  enum PickupDeliveryStatus { PICKUP, DELIVERY, NONE };
  struct NodeCount {
    int non_pickup_delivery = 0;
    int pickup = 0;
    int delivery = 0;
  };

  int GetNonDeliveryCount(int type) const;
  int GetNonDeliveredCount(int type) const;

  virtual bool HasRegulationsToCheck() const = 0;
  virtual void InitializeCheck() {}
  virtual bool CheckTypeRegulations(int type) = 0;
  virtual bool FinalizeCheck() const { return true; }

  const RoutingModel& model_;

 private:
  std::vector<PickupDeliveryStatus> pickup_delivery_status_of_node_;
  std::vector<NodeCount> counts_of_type_;
};

class TypeIncompatibilityChecker : public TypeRegulationsChecker {
 public:
  TypeIncompatibilityChecker(const RoutingModel& model,
                             bool check_hard_incompatibilities);
  ~TypeIncompatibilityChecker() override {}

 private:
  bool HasRegulationsToCheck() const override;
  bool CheckTypeRegulations(int type) override;
  bool check_hard_incompatibilities_;
};

class TypeRequirementChecker : public TypeRegulationsChecker {
 public:
  explicit TypeRequirementChecker(const RoutingModel& model)
      : TypeRegulationsChecker(model) {}
  ~TypeRequirementChecker() override {}

 private:
  bool HasRegulationsToCheck() const override;
  void InitializeCheck() override {
    types_with_same_vehicle_requirements_on_route_.clear();
  }
  bool CheckTypeRegulations(int type) override;
  bool FinalizeCheck() const override;

  absl::flat_hash_set<int> types_with_same_vehicle_requirements_on_route_;
};

class TypeRegulationsConstraint : public Constraint {
 public:
  explicit TypeRegulationsConstraint(const RoutingModel& model);

  void Post() override;
  void InitialPropagate() override;

 private:
  void PropagateNodeRegulations(int node);
  void CheckRegulationsOnVehicle(int vehicle);

  const RoutingModel& model_;
  TypeIncompatibilityChecker incompatibility_checker_;
  TypeRequirementChecker requirement_checker_;
  std::vector<Demon*> vehicle_demons_;
};
#if !defined SWIG
class SimpleBoundCosts {
 public:
  struct BoundCost {
    int64 bound;
    int64 cost;
  };
  SimpleBoundCosts(int num_bounds, BoundCost default_bound_cost)
      : bound_costs_(num_bounds, default_bound_cost) {}
  BoundCost& bound_cost(int element) { return bound_costs_[element]; }
  BoundCost bound_cost(int element) const { return bound_costs_[element]; }
  int Size() { return bound_costs_.size(); }
  SimpleBoundCosts(const SimpleBoundCosts&) = delete;
  SimpleBoundCosts operator=(const SimpleBoundCosts&) = delete;

 private:
  std::vector<BoundCost> bound_costs_;
};
#endif  // !defined SWIG

// TODO(user): Break constraints need to know the service time of nodes
class RoutingDimension {
 public:
  ~RoutingDimension();
  RoutingModel* model() const { return model_; }
  int64 GetTransitValue(int64 from_index, int64 to_index, int64 vehicle) const;
  int64 GetTransitValueFromClass(int64 from_index, int64 to_index,
                                 int64 vehicle_class) const {
    return model_->TransitCallback(class_evaluators_[vehicle_class])(from_index,
                                                                     to_index);
  }
  IntVar* CumulVar(int64 index) const { return cumuls_[index]; }
  IntVar* TransitVar(int64 index) const { return transits_[index]; }
  IntVar* FixedTransitVar(int64 index) const { return fixed_transits_[index]; }
  IntVar* SlackVar(int64 index) const { return slacks_[index]; }

#if !defined(SWIGPYTHON)
  const std::vector<IntVar*>& cumuls() const { return cumuls_; }
  const std::vector<IntVar*>& fixed_transits() const { return fixed_transits_; }
  const std::vector<IntVar*>& transits() const { return transits_; }
  const std::vector<IntVar*>& slacks() const { return slacks_; }
#if !defined(SWIGCSHARP) && !defined(SWIGJAVA)
  const std::vector<SortedDisjointIntervalList>& forbidden_intervals() const {
    return forbidden_intervals_;
  }
  const std::vector<int64>& vehicle_capacities() const {
    return vehicle_capacities_;
  }
  const RoutingModel::TransitCallback2& transit_evaluator(int vehicle) const {
    return model_->TransitCallback(
        class_evaluators_[vehicle_to_class_[vehicle]]);
  }
  const RoutingModel::TransitCallback1& GetUnaryTransitEvaluator(
      int vehicle) const {
    return model_->UnaryTransitCallbackOrNull(
        class_evaluators_[vehicle_to_class_[vehicle]]);
  }
  bool AreVehicleTransitsPositive(int vehicle) const {
    return model()->is_transit_evaluator_positive_
        [class_evaluators_[vehicle_to_class_[vehicle]]];
  }
  int vehicle_to_class(int vehicle) const { return vehicle_to_class_[vehicle]; }
#endif  
#endif  
  void SetSpanUpperBoundForVehicle(int64 upper_bound, int vehicle);
  void SetSpanCostCoefficientForVehicle(int64 coefficient, int vehicle);
  void SetSpanCostCoefficientForAllVehicles(int64 coefficient);
  void SetGlobalSpanCostCoefficient(int64 coefficient);

#ifndef SWIG
  void SetCumulVarPiecewiseLinearCost(int64 index,
                                      const PiecewiseLinearFunction& cost);
  bool HasCumulVarPiecewiseLinearCost(int64 index) const;
  const PiecewiseLinearFunction* GetCumulVarPiecewiseLinearCost(
      int64 index) const;
#endif

  void SetCumulVarSoftUpperBound(int64 index, int64 upper_bound,
                                 int64 coefficient);
  bool HasCumulVarSoftUpperBound(int64 index) const;
  int64 GetCumulVarSoftUpperBound(int64 index) const;
  int64 GetCumulVarSoftUpperBoundCoefficient(int64 index) const;

  void SetCumulVarSoftLowerBound(int64 index, int64 lower_bound,
                                 int64 coefficient);
  bool HasCumulVarSoftLowerBound(int64 index) const;
  int64 GetCumulVarSoftLowerBound(int64 index) const;
  int64 GetCumulVarSoftLowerBoundCoefficient(int64 index) const;
  // TODO(user): Remove if !defined when routing.i is repaired.
#if !defined(SWIGPYTHON)
  void SetBreakIntervalsOfVehicle(std::vector<IntervalVar*> breaks, int vehicle,
                                  int pre_travel_evaluator,
                                  int post_travel_evaluator);
#endif  // !defined(SWIGPYTHON)

  void SetBreakIntervalsOfVehicle(std::vector<IntervalVar*> breaks, int vehicle,
                                  std::vector<int64> node_visit_transits);

  void SetBreakDistanceDurationOfVehicle(int64 distance, int64 duration,
                                         int vehicle);
  void InitializeBreaks();
  bool HasBreakConstraints() const;
#if !defined(SWIGPYTHON)
  void SetBreakIntervalsOfVehicle(
      std::vector<IntervalVar*> breaks, int vehicle,
      std::vector<int64> node_visit_transits,
      std::function<int64(int64, int64)> group_delays);

  const std::vector<IntervalVar*>& GetBreakIntervalsOfVehicle(
      int vehicle) const;
  // clang-format off
  const std::vector<std::pair<int64, int64> >&
      GetBreakDistanceDurationOfVehicle(int vehicle) const;
  // clang-format on
#endif  
  int GetPreTravelEvaluatorOfVehicle(int vehicle) const;
  int GetPostTravelEvaluatorOfVehicle(int vehicle) const;

  const RoutingDimension* base_dimension() const { return base_dimension_; }
  int64 ShortestTransitionSlack(int64 node) const;

  const std::string& name() const { return name_; }

#ifndef SWIG
  const ReverseArcListGraph<int, int>& GetPathPrecedenceGraph() const {
    return path_precedence_graph_;
  }
#endif  // SWIG

  typedef std::function<int64(int, int)> PickupToDeliveryLimitFunction;

  void SetPickupToDeliveryLimitFunctionForPair(
      PickupToDeliveryLimitFunction limit_function, int pair_index);

  bool HasPickupToDeliveryLimits() const;
#ifndef SWIG
  int64 GetPickupToDeliveryLimitForPair(int pair_index, int pickup,
                                        int delivery) const;

  struct NodePrecedence {
    int64 first_node;
    int64 second_node;
    int64 offset;
  };

  void AddNodePrecedence(NodePrecedence precedence) {
    node_precedences_.push_back(precedence);
  }
  const std::vector<NodePrecedence>& GetNodePrecedences() const {
    return node_precedences_;
  }
#endif  // SWIG

  void AddNodePrecedence(int64 first_node, int64 second_node, int64 offset) {
    AddNodePrecedence({first_node, second_node, offset});
  }

  int64 GetSpanUpperBoundForVehicle(int vehicle) const {
    return vehicle_span_upper_bounds_[vehicle];
  }
#ifndef SWIG
  const std::vector<int64>& vehicle_span_upper_bounds() const {
    return vehicle_span_upper_bounds_;
  }
#endif  // SWIG
  int64 GetSpanCostCoefficientForVehicle(int vehicle) const {
    return vehicle_span_cost_coefficients_[vehicle];
  }
#ifndef SWIG
  const std::vector<int64>& vehicle_span_cost_coefficients() const {
    return vehicle_span_cost_coefficients_;
  }
#endif  // SWIG
  int64 global_span_cost_coefficient() const {
    return global_span_cost_coefficient_;
  }

  int64 GetGlobalOptimizerOffset() const {
    DCHECK_GE(global_optimizer_offset_, 0);
    return global_optimizer_offset_;
  }
  int64 GetLocalOptimizerOffsetForVehicle(int vehicle) const {
    if (vehicle >= local_optimizer_offset_for_vehicle_.size()) {
      return 0;
    }
    DCHECK_GE(local_optimizer_offset_for_vehicle_[vehicle], 0);
    return local_optimizer_offset_for_vehicle_[vehicle];
  }
#if !defined SWIG
  void SetSoftSpanUpperBoundForVehicle(SimpleBoundCosts::BoundCost bound_cost,
                                       int vehicle) {
    if (!HasSoftSpanUpperBounds()) {
      vehicle_soft_span_upper_bound_ = absl::make_unique<SimpleBoundCosts>(
          model_->vehicles(), SimpleBoundCosts::BoundCost{kint64max, 0});
    }
    vehicle_soft_span_upper_bound_->bound_cost(vehicle) = bound_cost;
  }
  bool HasSoftSpanUpperBounds() const {
    return vehicle_soft_span_upper_bound_ != nullptr;
  }
  SimpleBoundCosts::BoundCost GetSoftSpanUpperBoundForVehicle(
      int vehicle) const {
    DCHECK(HasSoftSpanUpperBounds());
    return vehicle_soft_span_upper_bound_->bound_cost(vehicle);
  }
#endif  

 private:
  struct SoftBound {
    IntVar* var;
    int64 bound;
    int64 coefficient;
  };

  struct PiecewiseLinearCost {
    PiecewiseLinearCost() : var(nullptr), cost(nullptr) {}
    IntVar* var;
    std::unique_ptr<PiecewiseLinearFunction> cost;
  };

  class SelfBased {};
  RoutingDimension(RoutingModel* model, std::vector<int64> vehicle_capacities,
                   const std::string& name,
                   const RoutingDimension* base_dimension);
  RoutingDimension(RoutingModel* model, std::vector<int64> vehicle_capacities,
                   const std::string& name, SelfBased);
  void Initialize(const std::vector<int>& transit_evaluators,
                  const std::vector<int>& state_dependent_transit_evaluators,
                  int64 slack_max);
  void InitializeCumuls();
  void InitializeTransits(
      const std::vector<int>& transit_evaluators,
      const std::vector<int>& state_dependent_transit_evaluators,
      int64 slack_max);
  void InitializeTransitVariables(int64 slack_max);
  void SetupCumulVarSoftUpperBoundCosts(
      std::vector<IntVar*>* cost_elements) const;
  void SetupCumulVarSoftLowerBoundCosts(
      std::vector<IntVar*>* cost_elements) const;
  void SetupCumulVarPiecewiseLinearCosts(
      std::vector<IntVar*>* cost_elements) const;
  void SetupGlobalSpanCost(std::vector<IntVar*>* cost_elements) const;
  void SetupSlackAndDependentTransitCosts() const;
  void CloseModel(bool use_light_propagation);

  void SetOffsetForGlobalOptimizer(int64 offset) {
    global_optimizer_offset_ = std::max(Zero(), offset);
  }
  void SetVehicleOffsetsForLocalOptimizer(std::vector<int64> offsets) {
    std::transform(offsets.begin(), offsets.end(), offsets.begin(),
                   [](int64 offset) { return std::max(Zero(), offset); });
    local_optimizer_offset_for_vehicle_ = std::move(offsets);
  }

  std::vector<IntVar*> cumuls_;
  std::vector<SortedDisjointIntervalList> forbidden_intervals_;
  std::vector<IntVar*> capacity_vars_;
  const std::vector<int64> vehicle_capacities_;
  std::vector<IntVar*> transits_;
  std::vector<IntVar*> fixed_transits_;
  std::vector<int> class_evaluators_;
  std::vector<int64> vehicle_to_class_;
#ifndef SWIG
  ReverseArcListGraph<int, int> path_precedence_graph_;
#endif
  // For every {first_node, second_node, offset} element in node_precedences_,
  // if both first_node and second_node are performed, then
  // cumuls_[second_node] must be greater than (or equal to)
  // cumuls_[first_node] + offset.
  std::vector<NodePrecedence> node_precedences_;

  // The transits of a dimension may depend on its cumuls or the cumuls of
  // another dimension. There can be no cycles, except for self loops, a
  // typical example for this is a time dimension.
  const RoutingDimension* const base_dimension_;

  // Values in state_dependent_class_evaluators_ correspond to the evaluators
  // in RoutingModel::state_dependent_transit_evaluators_ for each vehicle
  // class.
  std::vector<int> state_dependent_class_evaluators_;
  std::vector<int64> state_dependent_vehicle_to_class_;

  // For each pickup/delivery pair_index for which limits have been set,
  // pickup_to_delivery_limits_per_pair_index_[pair_index] contains the
  // PickupToDeliveryLimitFunction for the pickup and deliveries in this pair.
  std::vector<PickupToDeliveryLimitFunction>
      pickup_to_delivery_limits_per_pair_index_;

  // Used if some vehicle has breaks in this dimension, typically time.
  bool break_constraints_are_initialized_ = false;
  // clang-format off
  std::vector<std::vector<IntervalVar*> > vehicle_break_intervals_;
  std::vector<std::vector<std::pair<int64, int64> > >
      vehicle_break_distance_duration_;
  // clang-format on
  // For each vehicle, stores the part of travel that is made directly
  // after (before) the departure (arrival) node of the travel.
  // These parts of the travel are non-interruptible, in particular by a break.
  std::vector<int> vehicle_pre_travel_evaluators_;
  std::vector<int> vehicle_post_travel_evaluators_;

  std::vector<IntVar*> slacks_;
  std::vector<IntVar*> dependent_transits_;
  std::vector<int64> vehicle_span_upper_bounds_;
  int64 global_span_cost_coefficient_;
  std::vector<int64> vehicle_span_cost_coefficients_;
  std::vector<SoftBound> cumul_var_soft_upper_bound_;
  std::vector<SoftBound> cumul_var_soft_lower_bound_;
  std::vector<PiecewiseLinearCost> cumul_var_piecewise_linear_cost_;
  RoutingModel* const model_;
  const std::string name_;
  int64 global_optimizer_offset_;
  std::vector<int64> local_optimizer_offset_for_vehicle_;
  std::unique_ptr<SimpleBoundCosts> vehicle_soft_span_upper_bound_;
  friend class RoutingModel;
  friend class RoutingModelInspector;

  DISALLOW_COPY_AND_ASSIGN(RoutingDimension);
};

#ifndef SWIG
class SweepArranger {
 public:
  explicit SweepArranger(const std::vector<std::pair<int64, int64>>& points);
  virtual ~SweepArranger() {}
  void ArrangeIndices(std::vector<int64>* indices);
  void SetSectors(int sectors) { sectors_ = sectors; }

 private:
  std::vector<int> coordinates_;
  int sectors_;

  DISALLOW_COPY_AND_ASSIGN(SweepArranger);
};
#endif

DecisionBuilder* MakeSetValuesFromTargets(Solver* solver,
                                          std::vector<IntVar*> variables,
                                          std::vector<int64> targets);


// TODO(user): Eventually move this to the core CP solver library
class IntVarFilteredDecisionBuilder : public DecisionBuilder {
 public:
  IntVarFilteredDecisionBuilder(Solver* solver,
                                const std::vector<IntVar*>& vars,
                                const std::vector<LocalSearchFilter*>& filters);
  ~IntVarFilteredDecisionBuilder() override {}
  Decision* Next(Solver* solver) override;
  virtual bool BuildSolution() = 0;
  int64 number_of_decisions() const { return number_of_decisions_; }
  int64 number_of_rejects() const { return number_of_rejects_; }

 protected:
  virtual bool InitializeSolution() { return true; }
  bool Commit();
  virtual bool StopSearch() { return false; }
  void SetValue(int64 index, int64 value) {
    if (!is_in_delta_[index]) {
      delta_->FastAdd(vars_[index])->SetValue(value);
      delta_indices_.push_back(index);
      is_in_delta_[index] = true;
    } else {
      delta_->SetValue(vars_[index], value);
    }
  }
  int64 Value(int64 index) const {
    return assignment_->IntVarContainer().Element(index).Value();
  }
  bool Contains(int64 index) const {
    return assignment_->IntVarContainer().Element(index).Var() != nullptr;
  }
  int Size() const { return vars_.size(); }
  IntVar* Var(int64 index) const { return vars_[index]; }

 private:
  void SynchronizeFilters();
  bool FilterAccept();

  const std::vector<IntVar*> vars_;
  Assignment* const assignment_;
  Assignment* const delta_;
  std::vector<int> delta_indices_;
  std::vector<bool> is_in_delta_;
  Assignment* const empty_;
  LocalSearchFilterManager filter_manager_;
  int64 number_of_decisions_;
  int64 number_of_rejects_;
};

class RoutingFilteredDecisionBuilder : public IntVarFilteredDecisionBuilder {
 public:
  RoutingFilteredDecisionBuilder(
      RoutingModel* model, const std::vector<LocalSearchFilter*>& filters);
  ~RoutingFilteredDecisionBuilder() override {}
  RoutingModel* model() const { return model_; }
  int GetStartChainEnd(int vehicle) const { return start_chain_ends_[vehicle]; }
  int GetEndChainStart(int vehicle) const { return end_chain_starts_[vehicle]; }
  void MakeDisjunctionNodesUnperformed(int64 node);
  void MakeUnassignedNodesUnperformed();

 protected:
  bool StopSearch() override { return model_->CheckLimit(); }

 private:
  bool InitializeSolution() override;

  RoutingModel* const model_;
  std::vector<int64> start_chain_ends_;
  std::vector<int64> end_chain_starts_;
};

class CheapestInsertionFilteredDecisionBuilder
    : public RoutingFilteredDecisionBuilder {
 public:
  CheapestInsertionFilteredDecisionBuilder(
      RoutingModel* model, std::function<int64(int64, int64, int64)> evaluator,
      std::function<int64(int64)> penalty_evaluator,
      const std::vector<LocalSearchFilter*>& filters);
  ~CheapestInsertionFilteredDecisionBuilder() override {}

 protected:
  typedef std::pair<int64, int64> ValuedPosition;
  struct StartEndValue {
    int64 distance;
    int vehicle;

    bool operator<(const StartEndValue& other) const {
      return std::tie(distance, vehicle) <
             std::tie(other.distance, other.vehicle);
    }
  };
  typedef std::pair<StartEndValue, /*seed_node*/ int> Seed;

  // clang-format off
  std::vector<std::vector<StartEndValue> >
      ComputeStartEndDistanceForVehicles(const std::vector<int>& vehicles);

  template <class Queue>
  void InitializePriorityQueue(
      std::vector<std::vector<StartEndValue> >* start_end_distances_per_node,
      Queue* priority_queue);
  // clang-format on

  void InsertBetween(int64 node, int64 predecessor, int64 successor);
  void AppendEvaluatedPositionsAfter(
      int64 node_to_insert, int64 start, int64 next_after_start, int64 vehicle,
      std::vector<ValuedPosition>* valued_positions);
  int64 GetUnperformedValue(int64 node_to_insert) const;

  std::function<int64(int64, int64, int64)> evaluator_;
  std::function<int64(int64)> penalty_evaluator_;
};

class GlobalCheapestInsertionFilteredDecisionBuilder
    : public CheapestInsertionFilteredDecisionBuilder {
 public:
  GlobalCheapestInsertionFilteredDecisionBuilder(
      RoutingModel* model, std::function<int64(int64, int64, int64)> evaluator,
      std::function<int64(int64)> penalty_evaluator,
      const std::vector<LocalSearchFilter*>& filters, bool is_sequential,
      double farthest_seeds_ratio, double neighbors_ratio);
  ~GlobalCheapestInsertionFilteredDecisionBuilder() override {}
  bool BuildSolution() override;
  std::string DebugString() const override {
    return "GlobalCheapestInsertionFilteredDecisionBuilder";
  }

 private:
  class PairEntry;
  class NodeEntry;
  typedef absl::flat_hash_set<PairEntry*> PairEntries;
  typedef absl::flat_hash_set<NodeEntry*> NodeEntries;

  void InsertPairs();

  void InsertNodesOnRoutes(const std::vector<int>& nodes,
                           const std::vector<int>& vehicles);

  void SequentialInsertNodes(const std::vector<int>& nodes);

  void DetectUsedVehicles(std::vector<bool>* is_vehicle_used,
                          std::vector<int>* used_vehicles,
                          std::vector<int>* unused_vehicles);

  void InsertFarthestNodesAsSeeds();

  template <class Queue>
  int InsertSeedNode(
      std::vector<std::vector<StartEndValue>>* start_end_distances_per_node,
      Queue* priority_queue, std::vector<bool>* is_vehicle_used);
  // clang-format on

  void InitializePairPositions(
      AdjustablePriorityQueue<PairEntry>* priority_queue,
      std::vector<PairEntries>* pickup_to_entries,
      std::vector<PairEntries>* delivery_to_entries);
  void UpdatePairPositions(int vehicle, int64 insert_after,
                           AdjustablePriorityQueue<PairEntry>* priority_queue,
                           std::vector<PairEntries>* pickup_to_entries,
                           std::vector<PairEntries>* delivery_to_entries) {
    UpdatePickupPositions(vehicle, insert_after, priority_queue,
                          pickup_to_entries, delivery_to_entries);
    UpdateDeliveryPositions(vehicle, insert_after, priority_queue,
                            pickup_to_entries, delivery_to_entries);
  }
  void UpdatePickupPositions(int vehicle, int64 pickup_insert_after,
                             AdjustablePriorityQueue<PairEntry>* priority_queue,
                             std::vector<PairEntries>* pickup_to_entries,
                             std::vector<PairEntries>* delivery_to_entries);
  void UpdateDeliveryPositions(
      int vehicle, int64 delivery_insert_after,
      AdjustablePriorityQueue<PairEntry>* priority_queue,
      std::vector<PairEntries>* pickup_to_entries,
      std::vector<PairEntries>* delivery_to_entries);
  void DeletePairEntry(PairEntry* entry,
                       AdjustablePriorityQueue<PairEntry>* priority_queue,
                       std::vector<PairEntries>* pickup_to_entries,
                       std::vector<PairEntries>* delivery_to_entries);
  void InitializePositions(const std::vector<int>& nodes,
                           AdjustablePriorityQueue<NodeEntry>* priority_queue,
                           std::vector<NodeEntries>* position_to_node_entries,
                           const std::vector<int>& vehicles);
  void UpdatePositions(const std::vector<int>& nodes, int vehicle,
                       int64 insert_after,
                       AdjustablePriorityQueue<NodeEntry>* priority_queue,
                       std::vector<NodeEntries>* node_entries);
  void DeleteNodeEntry(NodeEntry* entry,
                       AdjustablePriorityQueue<NodeEntry>* priority_queue,
                       std::vector<NodeEntries>* node_entries);

  void AddNeighborForCostClass(int cost_class, int64 node_index,
                               int64 neighbor_index, bool neighbor_is_pickup,
                               bool neighbor_is_delivery);

  bool IsNeighborForCostClass(int cost_class, int64 node_index,
                              int64 neighbor_index) const;

  const absl::flat_hash_set<int64>& GetPickupNeighborsOfNodeForCostClass(
      int cost_class, int64 node_index) {
    if (neighbors_ratio_ == 1) {
      return pickup_nodes_;
    }
    return node_index_to_pickup_neighbors_by_cost_class_[node_index]
                                                        [cost_class];
  }

  const absl::flat_hash_set<int64>& GetDeliveryNeighborsOfNodeForCostClass(
      int cost_class, int64 node_index) {
    if (neighbors_ratio_ == 1) {
      return delivery_nodes_;
    }
    return node_index_to_delivery_neighbors_by_cost_class_[node_index]
                                                          [cost_class];
  }

  const bool is_sequential_;
  const double farthest_seeds_ratio_;
  const double neighbors_ratio_;

  // clang-format off
  std::vector<std::vector<absl::flat_hash_set<int64> > >
      node_index_to_single_neighbors_by_cost_class_;
  std::vector<std::vector<absl::flat_hash_set<int64> > >
      node_index_to_pickup_neighbors_by_cost_class_;
  std::vector<std::vector<absl::flat_hash_set<int64> > >
      node_index_to_delivery_neighbors_by_cost_class_;
  // clang-format on

  absl::flat_hash_set<int64> pickup_nodes_;
  absl::flat_hash_set<int64> delivery_nodes_;
};

class LocalCheapestInsertionFilteredDecisionBuilder
    : public CheapestInsertionFilteredDecisionBuilder {
 public:
  LocalCheapestInsertionFilteredDecisionBuilder(
      RoutingModel* model, std::function<int64(int64, int64, int64)> evaluator,
      const std::vector<LocalSearchFilter*>& filters);
  ~LocalCheapestInsertionFilteredDecisionBuilder() override {}
  bool BuildSolution() override;
  std::string DebugString() const override {
    return "LocalCheapestInsertionFilteredDecisionBuilder";
  }

 private:
  void ComputeEvaluatorSortedPositions(int64 node,
                                       std::vector<int64>* sorted_positions);
  void ComputeEvaluatorSortedPositionsOnRouteAfter(
      int64 node, int64 start, int64 next_after_start,
      std::vector<int64>* sorted_positions);
};

class CheapestAdditionFilteredDecisionBuilder
    : public RoutingFilteredDecisionBuilder {
 public:
  CheapestAdditionFilteredDecisionBuilder(
      RoutingModel* model, const std::vector<LocalSearchFilter*>& filters);
  ~CheapestAdditionFilteredDecisionBuilder() override {}
  bool BuildSolution() override;

 private:
  class PartialRoutesAndLargeVehicleIndicesFirst {
   public:
    explicit PartialRoutesAndLargeVehicleIndicesFirst(
        const CheapestAdditionFilteredDecisionBuilder& builder)
        : builder_(builder) {}
    bool operator()(int vehicle1, int vehicle2) const;

   private:
    const CheapestAdditionFilteredDecisionBuilder& builder_;
  };
  template <typename Iterator>
  std::vector<int64> GetPossibleNextsFromIterator(int64 node, Iterator start,
                                                  Iterator end) const {
    const int size = model()->Size();
    std::vector<int64> nexts;
    for (Iterator it = start; it != end; ++it) {
      const int64 next = *it;
      if (next != node && (next >= size || !Contains(next))) {
        nexts.push_back(next);
      }
    }
    return nexts;
  }
  virtual void SortSuccessors(int64 node, std::vector<int64>* successors) = 0;
  virtual int64 FindTopSuccessor(int64 node,
                                 const std::vector<int64>& successors) = 0;
};

class EvaluatorCheapestAdditionFilteredDecisionBuilder
    : public CheapestAdditionFilteredDecisionBuilder {
 public:
  EvaluatorCheapestAdditionFilteredDecisionBuilder(
      RoutingModel* model, std::function<int64(int64, int64)> evaluator,
      const std::vector<LocalSearchFilter*>& filters);
  ~EvaluatorCheapestAdditionFilteredDecisionBuilder() override {}
  std::string DebugString() const override {
    return "EvaluatorCheapestAdditionFilteredDecisionBuilder";
  }

 private:
  void SortSuccessors(int64 node, std::vector<int64>* successors) override;
  int64 FindTopSuccessor(int64 node,
                         const std::vector<int64>& successors) override;

  std::function<int64(int64, int64)> evaluator_;
};

class ComparatorCheapestAdditionFilteredDecisionBuilder
    : public CheapestAdditionFilteredDecisionBuilder {
 public:
  ComparatorCheapestAdditionFilteredDecisionBuilder(
      RoutingModel* model, Solver::VariableValueComparator comparator,
      const std::vector<LocalSearchFilter*>& filters);
  ~ComparatorCheapestAdditionFilteredDecisionBuilder() override {}
  std::string DebugString() const override {
    return "ComparatorCheapestAdditionFilteredDecisionBuilder";
  }

 private:
  void SortSuccessors(int64 node, std::vector<int64>* successors) override;
  int64 FindTopSuccessor(int64 node,
                         const std::vector<int64>& successors) override;

  Solver::VariableValueComparator comparator_;
};

class SavingsFilteredDecisionBuilder : public RoutingFilteredDecisionBuilder {
 public:
  struct SavingsParameters {
    double neighbors_ratio = 1.0;
    double max_memory_usage_bytes = 6e9;
    bool add_reverse_arcs = false;
    double arc_coefficient = 1.0;
  };

  SavingsFilteredDecisionBuilder(
      RoutingModel* model, RoutingIndexManager* manager,
      SavingsParameters parameters,
      const std::vector<LocalSearchFilter*>& filters);
  ~SavingsFilteredDecisionBuilder() override;
  bool BuildSolution() override;

 protected:
  typedef std::pair</*saving*/ int64, /*saving index*/ int64> Saving;

  template <typename S>
  class SavingsContainer;

  struct VehicleClassEntry {
    int vehicle_class;
    int64 fixed_cost;

    bool operator<(const VehicleClassEntry& other) const {
      return std::tie(fixed_cost, vehicle_class) <
             std::tie(other.fixed_cost, other.vehicle_class);
    }
  };

  virtual double ExtraSavingsMemoryMultiplicativeFactor() const = 0;

  virtual void BuildRoutesFromSavings() = 0;

  int64 GetVehicleTypeFromSaving(const Saving& saving) const {
    return saving.second / size_squared_;
  }
  int64 GetBeforeNodeFromSaving(const Saving& saving) const {
    return (saving.second % size_squared_) / Size();
  }
  int64 GetAfterNodeFromSaving(const Saving& saving) const {
    return (saving.second % size_squared_) % Size();
  }
  int64 GetSavingValue(const Saving& saving) const { return saving.first; }

  int StartNewRouteWithBestVehicleOfType(int type, int64 before_node,
                                         int64 after_node);

  std::vector<int> type_index_of_vehicle_;
  // clang-format off
  std::vector<std::set<VehicleClassEntry> > sorted_vehicle_classes_per_type_;
  std::vector<std::deque<int> > vehicles_per_vehicle_class_;
  std::unique_ptr<SavingsContainer<Saving> > savings_container_;
  // clang-format on

 private:
  void AddSymetricArcsToAdjacencyLists(
      std::vector<std::vector<int64>>* adjacency_lists);
  // clang-format on

  void ComputeSavings();
  Saving BuildSaving(int64 saving, int vehicle_type, int before_node,
                     int after_node) const {
    return std::make_pair(saving, vehicle_type * size_squared_ +
                                      before_node * Size() + after_node);
  }

  void ComputeVehicleTypes();

  int64 MaxNumNeighborsPerNode(int num_vehicle_types) const;

  RoutingIndexManager* const manager_;
  const SavingsParameters savings_params_;
  int64 size_squared_;

  friend class SavingsFilteredDecisionBuilderTestPeer;
};

class SequentialSavingsFilteredDecisionBuilder
    : public SavingsFilteredDecisionBuilder {
 public:
  SequentialSavingsFilteredDecisionBuilder(
      RoutingModel* model, RoutingIndexManager* manager,
      SavingsParameters parameters,
      const std::vector<LocalSearchFilter*>& filters)
      : SavingsFilteredDecisionBuilder(model, manager, parameters, filters) {}
  ~SequentialSavingsFilteredDecisionBuilder() override{};
  std::string DebugString() const override {
    return "SequentialSavingsFilteredDecisionBuilder";
  }

 private:
  void BuildRoutesFromSavings() override;
  double ExtraSavingsMemoryMultiplicativeFactor() const override { return 1.0; }
};

class ParallelSavingsFilteredDecisionBuilder
    : public SavingsFilteredDecisionBuilder {
 public:
  ParallelSavingsFilteredDecisionBuilder(
      RoutingModel* model, RoutingIndexManager* manager,
      SavingsParameters parameters,
      const std::vector<LocalSearchFilter*>& filters)
      : SavingsFilteredDecisionBuilder(model, manager, parameters, filters) {}
  ~ParallelSavingsFilteredDecisionBuilder() override{};
  std::string DebugString() const override {
    return "ParallelSavingsFilteredDecisionBuilder";
  }

 private:
  void BuildRoutesFromSavings() override;

  double ExtraSavingsMemoryMultiplicativeFactor() const override { return 2.0; }

  void MergeRoutes(int first_vehicle, int second_vehicle, int64 before_node,
                   int64 after_node);

  std::vector<int64> first_node_on_route_;
  std::vector<int64> last_node_on_route_;
  std::vector<int> vehicle_of_first_or_last_node_;
};


class ChristofidesFilteredDecisionBuilder
    : public RoutingFilteredDecisionBuilder {
 public:
  ChristofidesFilteredDecisionBuilder(
      RoutingModel* model, const std::vector<LocalSearchFilter*>& filters);
  ~ChristofidesFilteredDecisionBuilder() override {}
  bool BuildSolution() override;
  std::string DebugString() const override {
    return "ChristofidesFilteredDecisionBuilder";
  }
};

bool SolveModelWithSat(const RoutingModel& model,
                       const RoutingSearchParameters& search_parameters,
                       const Assignment* initial_solution,
                       Assignment* solution);


class BasePathFilter : public IntVarLocalSearchFilter {
 public:
  BasePathFilter(const std::vector<IntVar*>& nexts, int next_domain_size);
  ~BasePathFilter() override {}
  bool Accept(const Assignment* delta, const Assignment* deltadelta,
              int64 objective_min, int64 objective_max) override;
  void OnSynchronize(const Assignment* delta) override;

 protected:
  static const int64 kUnassigned;

  int64 GetNext(int64 node) const {
    return (new_nexts_[node] == kUnassigned)
               ? (IsVarSynced(node) ? Value(node) : kUnassigned)
               : new_nexts_[node];
  }
  int NumPaths() const { return starts_.size(); }
  int64 Start(int i) const { return starts_[i]; }
  int GetPath(int64 node) const { return paths_[node]; }
  int Rank(int64 node) const { return ranks_[node]; }
  bool IsDisabled() const { return status_ == DISABLED; }
  const std::vector<int64>& GetNewSynchronizedUnperformedNodes() const {
    return new_synchronized_unperformed_nodes_.PositionsSetAtLeastOnce();
  }

 private:
  enum Status { UNKNOWN, ENABLED, DISABLED };

  virtual bool DisableFiltering() const { return false; }
  virtual void OnBeforeSynchronizePaths() {}
  virtual void OnAfterSynchronizePaths() {}
  virtual void OnSynchronizePathFromStart(int64 start) {}
  virtual void InitializeAcceptPath() {}
  virtual bool AcceptPath(int64 path_start, int64 chain_start,
                          int64 chain_end) = 0;
  virtual bool FinalizeAcceptPath(const Assignment* delta, int64 objective_min,
                                  int64 objective_max) {
    return true;
  }
  void ComputePathStarts(std::vector<int64>* path_starts,
                         std::vector<int>* index_to_path);
  bool HavePathsChanged();
  void SynchronizeFullAssignment();
  void UpdateAllRanks();
  void UpdatePathRanksFromStart(int start);

  std::vector<int64> node_path_starts_;
  std::vector<int64> starts_;
  std::vector<int> paths_;
  SparseBitset<int64> new_synchronized_unperformed_nodes_;
  std::vector<int64> new_nexts_;
  std::vector<int> delta_touched_;
  SparseBitset<> touched_paths_;
  SparseBitset<> touched_path_nodes_;
  std::vector<int> ranks_;

  Status status_;
};

// TODO(user): Also call the solution finalizer on variables, with the
// TODO(user): Avoid such false negatives.
class CPFeasibilityFilter : public IntVarLocalSearchFilter {
 public:
  explicit CPFeasibilityFilter(const RoutingModel* routing_model);
  ~CPFeasibilityFilter() override {}
  std::string DebugString() const override { return "CPFeasibilityFilter"; }
  bool Accept(const Assignment* delta, const Assignment* deltadelta,
              int64 objective_min, int64 objective_max) override;
  void OnSynchronize(const Assignment* delta) override;

 private:
  void AddDeltaToAssignment(const Assignment* delta, Assignment* assignment);

  static const int64 kUnassigned;
  const RoutingModel* const model_;
  Solver* const solver_;
  Assignment* const assignment_;
  Assignment* const temp_assignment_;
  DecisionBuilder* const restore_;
};

#if !defined(SWIG)
IntVarLocalSearchFilter* MakeNodeDisjunctionFilter(
    const RoutingModel& routing_model);
IntVarLocalSearchFilter* MakeVehicleAmortizedCostFilter(
    const RoutingModel& routing_model);
IntVarLocalSearchFilter* MakeTypeRegulationsFilter(
    const RoutingModel& routing_model);
std::vector<IntVarLocalSearchFilter*> MakeCumulFilters(
    const RoutingDimension& dimension, bool filter_objective_cost);
IntVarLocalSearchFilter* MakePathCumulFilter(const RoutingDimension& dimension,
                                             bool propagate_own_objective_value,
                                             bool filter_objective_cost);
IntVarLocalSearchFilter* MakeGlobalLPCumulFilter(
    GlobalDimensionCumulOptimizer* optimizer, bool filter_objective_cost);
IntVarLocalSearchFilter* MakePickupDeliveryFilter(
    const RoutingModel& routing_model, const RoutingModel::IndexPairs& pairs,
    const std::vector<RoutingModel::PickupAndDeliveryPolicy>& vehicle_policies);
IntVarLocalSearchFilter* MakeVehicleVarFilter(
    const RoutingModel& routing_model);
IntVarLocalSearchFilter* MakeVehicleBreaksFilter(
    const RoutingModel& routing_model, const RoutingDimension& dimension);
IntVarLocalSearchFilter* MakeCPFeasibilityFilter(
    const RoutingModel* routing_model);
#endif

}  // namespace operations_research
#endif  // OR_TOOLS_CONSTRAINT_SOLVER_ROUTING_H_