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16#include <cstdint>

17#include <cstdlib>

18#include <sstream>

19#include <vector>

20

27

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30

31struct DataModel {

32 const std::vector<std::vector<int64_t>> distance_matrix{

33 {0, 548, 776, 696, 582, 274, 502, 194, 308, 194, 536, 502, 388, 354, 468,

34 776, 662},

35 {548, 0, 684, 308, 194, 502, 730, 354, 696, 742, 1084, 594, 480, 674,

36 1016, 868, 1210},

37 {776, 684, 0, 992, 878, 502, 274, 810, 468, 742, 400, 1278, 1164, 1130,

38 788, 1552, 754},

39 {696, 308, 992, 0, 114, 650, 878, 502, 844, 890, 1232, 514, 628, 822,

40 1164, 560, 1358},

41 {582, 194, 878, 114, 0, 536, 764, 388, 730, 776, 1118, 400, 514, 708,

42 1050, 674, 1244},

43 {274, 502, 502, 650, 536, 0, 228, 308, 194, 240, 582, 776, 662, 628, 514,

44 1050, 708},

45 {502, 730, 274, 878, 764, 228, 0, 536, 194, 468, 354, 1004, 890, 856, 514,

46 1278, 480},

47 {194, 354, 810, 502, 388, 308, 536, 0, 342, 388, 730, 468, 354, 320, 662,

48 742, 856},

49 {308, 696, 468, 844, 730, 194, 194, 342, 0, 274, 388, 810, 696, 662, 320,

50 1084, 514},

51 {194, 742, 742, 890, 776, 240, 468, 388, 274, 0, 342, 536, 422, 388, 274,

52 810, 468},

53 {536, 1084, 400, 1232, 1118, 582, 354, 730, 388, 342, 0, 878, 764, 730,

54 388, 1152, 354},

55 {502, 594, 1278, 514, 400, 776, 1004, 468, 810, 536, 878, 0, 114, 308,

56 650, 274, 844},

57 {388, 480, 1164, 628, 514, 662, 890, 354, 696, 422, 764, 114, 0, 194, 536,

58 388, 730},

59 {354, 674, 1130, 822, 708, 628, 856, 320, 662, 388, 730, 308, 194, 0, 342,

60 422, 536},

61 {468, 1016, 788, 1164, 1050, 514, 514, 662, 320, 274, 388, 650, 536, 342,

62 0, 764, 194},

63 {776, 868, 1552, 560, 674, 1050, 1278, 742, 1084, 810, 1152, 274, 388,

64 422, 764, 0, 798},

65 {662, 1210, 754, 1358, 1244, 708, 480, 856, 514, 468, 354, 844, 730, 536,

66 194, 798, 0},

67 };

68 const int num_vehicles = 4;

69 const RoutingIndexManager::NodeIndex depot{0};

70};

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79void PrintSolution(const RoutingIndexManager& manager,

80 const RoutingModel& routing, const Assignment& solution) {

85 LOG(ERROR) << "No Solution found!";

86 return;

87 }

88 LOG(INFO) << "Objective: " << solution.ObjectiveValue();

89 int64_t total_distance{0};

90 for (int vehicle_id = 0; vehicle_id < manager.num_vehicles(); ++vehicle_id) {

91 if (!routing.IsVehicleUsed(solution, vehicle_id)) {

92 continue;

93 }

94 int64_t index = routing.Start(vehicle_id);

95 LOG(INFO) << "Route for Vehicle " << vehicle_id << ":";

96 int64_t distance{0};

97 std::stringstream route;

98 while (!routing.IsEnd(index)) {

99 route << manager.IndexToNode(index).value() << " -> ";

100 const int64_t previous_index = index;

101 index = solution.Value(routing.NextVar(index));

102 distance += routing.GetArcCostForVehicle(previous_index, index,

103 int64_t{vehicle_id});

104 }

105 LOG(INFO) << route.str() << manager.IndexToNode(index).value();

106 LOG(INFO) << "Distance of the route: " << distance << "m";

107 total_distance += distance;

108 }

109 LOG(INFO) << "Total distance of all routes: " << total_distance << "m";

110 LOG(INFO) << "";

111 LOG(INFO) << "Advanced usage:";

112 LOG(INFO) << "Problem solved in " << routing.solver()->wall_time() << "ms";

113}

114

115

116void Vrp() {

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119 DataModel data;

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124 RoutingIndexManager manager(data.distance_matrix.size(), data.num_vehicles,

125 data.depot);

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130 RoutingModel routing(manager);

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135 const int transit_callback_index = routing.RegisterTransitCallback(

136 [&data, &manager](const int64_t from_index,

137 const int64_t to_index) -> int64_t {

138

139 const int from_node = manager.IndexToNode(from_index).value();

140 const int to_node = manager.IndexToNode(to_index).value();

141 return data.distance_matrix[from_node][to_node];

142 });

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147 routing.SetArcCostEvaluatorOfAllVehicles(transit_callback_index);

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153 searchParameters.set_first_solution_strategy(

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159 const Assignment* solution = routing.SolveWithParameters(searchParameters);

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164 PrintSolution(manager, routing, *solution);

165

166}

167}

168

169int main(int , char* []) {

170 operations_research::Vrp();

171 return EXIT_SUCCESS;

172}

173