205 lines
8.0 KiB
C++
205 lines
8.0 KiB
C++
// Copyright 2010-2022 Google LLC
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// Vehicle Routing Problem with Breaks.:
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// A description of the Vehicle Routing Problem can be found here:
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// http://en.wikipedia.org/wiki/Vehicle_routing_problem.
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// This variant also includes vehicle breaks which must happen during the day
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// with two alternate breaks schemes: either a long break in the middle of the
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// day or two smaller ones which can be taken during a longer period of the day.
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// [START program]
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// [START import]
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#include <cstdint>
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#include <vector>
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#include "ortools/constraint_solver/constraint_solver.h"
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#include "ortools/constraint_solver/routing.h"
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#include "ortools/constraint_solver/routing_enums.pb.h"
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#include "ortools/constraint_solver/routing_index_manager.h"
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#include "ortools/constraint_solver/routing_parameters.h"
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// [END import]
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namespace operations_research {
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// [START data_model]
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struct DataModel {
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const std::vector<std::vector<int64_t>> time_matrix{
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{0, 27, 38, 34, 29, 13, 25, 9, 15, 9, 26, 25, 19, 17, 23, 38, 33},
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{27, 0, 34, 15, 9, 25, 36, 17, 34, 37, 54, 29, 24, 33, 50, 43, 60},
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{38, 34, 0, 49, 43, 25, 13, 40, 23, 37, 20, 63, 58, 56, 39, 77, 37},
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{34, 15, 49, 0, 5, 32, 43, 25, 42, 44, 61, 25, 31, 41, 58, 28, 67},
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{29, 9, 43, 5, 0, 26, 38, 19, 36, 38, 55, 20, 25, 35, 52, 33, 62},
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{13, 25, 25, 32, 26, 0, 11, 15, 9, 12, 29, 38, 33, 31, 25, 52, 35},
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{25, 36, 13, 43, 38, 11, 0, 26, 9, 23, 17, 50, 44, 42, 25, 63, 24},
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{9, 17, 40, 25, 19, 15, 26, 0, 17, 19, 36, 23, 17, 16, 33, 37, 42},
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{15, 34, 23, 42, 36, 9, 9, 17, 0, 13, 19, 40, 34, 33, 16, 54, 25},
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{9, 37, 37, 44, 38, 12, 23, 19, 13, 0, 17, 26, 21, 19, 13, 40, 23},
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{26, 54, 20, 61, 55, 29, 17, 36, 19, 17, 0, 43, 38, 36, 19, 57, 17},
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{25, 29, 63, 25, 20, 38, 50, 23, 40, 26, 43, 0, 5, 15, 32, 13, 42},
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{19, 24, 58, 31, 25, 33, 44, 17, 34, 21, 38, 5, 0, 9, 26, 19, 36},
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{17, 33, 56, 41, 35, 31, 42, 16, 33, 19, 36, 15, 9, 0, 17, 21, 26},
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{23, 50, 39, 58, 52, 25, 25, 33, 16, 13, 19, 32, 26, 17, 0, 38, 9},
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{38, 43, 77, 28, 33, 52, 63, 37, 54, 40, 57, 13, 19, 21, 38, 0, 39},
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{33, 60, 37, 67, 62, 35, 24, 42, 25, 23, 17, 42, 36, 26, 9, 39, 0},
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};
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const std::vector<int64_t> service_time{
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0, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
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};
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const int num_vehicles = 4;
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const RoutingIndexManager::NodeIndex depot{0};
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};
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// [END data_model]
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//! @brief Print the solution.
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//! @param[in] data Data of the problem.
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//! @param[in] manager Index manager used.
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//! @param[in] routing Routing solver used.
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//! @param[in] solution Solution found by the solver.
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// [START solution_printer]
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void PrintSolution(const RoutingIndexManager& manager,
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const RoutingModel& routing, const Assignment& solution) {
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LOG(INFO) << "Objective: " << solution.ObjectiveValue();
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LOG(INFO) << "Breaks:";
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const Assignment::IntervalContainer& intervals =
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solution.IntervalVarContainer();
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for (const IntervalVarElement& break_interval : intervals.elements()) {
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if (break_interval.PerformedValue()) {
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LOG(INFO) << break_interval.Var()->name() << " "
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<< break_interval.DebugString();
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} else {
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LOG(INFO) << break_interval.Var()->name() << ": Unperformed";
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}
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}
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const RoutingDimension& time_dimension = routing.GetDimensionOrDie("Time");
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int64_t total_time{0};
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for (int vehicle_id = 0; vehicle_id < manager.num_vehicles(); ++vehicle_id) {
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LOG(INFO) << "Route for Vehicle " << vehicle_id << ":";
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int64_t index = routing.Start(vehicle_id);
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std::stringstream route;
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while (routing.IsEnd(index) == false) {
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const IntVar* time_var = time_dimension.CumulVar(index);
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route << manager.IndexToNode(index).value() << " Time("
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<< solution.Value(time_var) << ") -> ";
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index = solution.Value(routing.NextVar(index));
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}
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const IntVar* time_var = time_dimension.CumulVar(index);
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route << manager.IndexToNode(index).value() << " Time("
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<< solution.Value(time_var) << ")";
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LOG(INFO) << route.str();
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LOG(INFO) << "Time of the route: " << solution.Value(time_var) << "min";
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total_time += solution.Value(time_var);
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}
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LOG(INFO) << "Total time of all routes: " << total_time << "min";
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LOG(INFO) << "";
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LOG(INFO) << "Problem solved in " << routing.solver()->wall_time() << "ms";
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}
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// [END solution_printer]
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void VrpBreaks() {
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// Instantiate the data problem.
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// [START data]
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DataModel data;
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// [END data]
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// Create Routing Index Manager
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// [START index_manager]
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RoutingIndexManager manager(data.time_matrix.size(), data.num_vehicles,
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data.depot);
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// [END index_manager]
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// Create Routing Model.
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// [START routing_model]
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RoutingModel routing(manager);
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// [END routing_model]
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// Create and register a transit callback.
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// [START transit_callback]
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const int transit_callback_index = routing.RegisterTransitCallback(
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[&data, &manager](int64_t from_index, int64_t to_index) -> int64_t {
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// Convert from routing variable Index to distance matrix NodeIndex.
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int from_node = manager.IndexToNode(from_index).value();
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int to_node = manager.IndexToNode(to_index).value();
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return data.time_matrix[from_node][to_node] +
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data.service_time[from_node];
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});
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// [END transit_callback]
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// Define cost of each arc.
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// [START arc_cost]
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routing.SetArcCostEvaluatorOfAllVehicles(transit_callback_index);
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// [END arc_cost]
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// Add Time constraint.
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// [START time_constraint]
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routing.AddDimension(transit_callback_index,
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10, // needed optional waiting time to place break
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180, // maximum time per vehicle
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true, // Force start cumul to zero.
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"Time");
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RoutingDimension* time_dimension = routing.GetMutableDimension("Time");
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time_dimension->SetGlobalSpanCostCoefficient(10);
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// [END time_constraint]
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// Add Breaks
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std::vector<int64_t> service_times(routing.Size());
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for (int index = 0; index < routing.Size(); index++) {
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const RoutingIndexManager::NodeIndex node = manager.IndexToNode(index);
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service_times[index] = data.service_time[node.value()];
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}
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Solver* const solver = routing.solver();
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for (int vehicle = 0; vehicle < manager.num_vehicles(); ++vehicle) {
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std::vector<IntervalVar*> break_intervals;
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IntervalVar* const break_interval = solver->MakeFixedDurationIntervalVar(
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50, // start min
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60, // start max
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10, // duration: 10min
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false, // optional: no
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absl::StrCat("Break for vehicle ", vehicle));
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break_intervals.push_back(break_interval);
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time_dimension->SetBreakIntervalsOfVehicle(break_intervals, vehicle,
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service_times);
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}
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// Setting first solution heuristic.
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// [START parameters]
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RoutingSearchParameters searchParameters = DefaultRoutingSearchParameters();
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searchParameters.set_first_solution_strategy(
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FirstSolutionStrategy::PATH_CHEAPEST_ARC);
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// [END parameters]
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// Solve the problem.
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// [START solve]
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const Assignment* solution = routing.SolveWithParameters(searchParameters);
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// [END solve]
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// Print solution on console.
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// [START print_solution]
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if (solution != nullptr) {
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PrintSolution(manager, routing, *solution);
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} else {
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LOG(INFO) << "No solution found.";
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}
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// [END print_solution]
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}
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} // namespace operations_research
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int main(int /*argc*/, char** argv) {
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operations_research::VrpBreaks();
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return EXIT_SUCCESS;
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}
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// [END program]
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