Google OR-Tools: vrp_starts_ends.cc
Simple VRP example.
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16#include <algorithm>
17#include <cstdint>
18#include <cstdlib>
19#include <sstream>
20#include <vector>
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31
32struct DataModel {
33 const std::vector<std::vector<int64_t>> distance_matrix{
34 {0, 548, 776, 696, 582, 274, 502, 194, 308, 194, 536, 502, 388, 354, 468,
35 776, 662},
36 {548, 0, 684, 308, 194, 502, 730, 354, 696, 742, 1084, 594, 480, 674,
37 1016, 868, 1210},
38 {776, 684, 0, 992, 878, 502, 274, 810, 468, 742, 400, 1278, 1164, 1130,
39 788, 1552, 754},
40 {696, 308, 992, 0, 114, 650, 878, 502, 844, 890, 1232, 514, 628, 822,
41 1164, 560, 1358},
42 {582, 194, 878, 114, 0, 536, 764, 388, 730, 776, 1118, 400, 514, 708,
43 1050, 674, 1244},
44 {274, 502, 502, 650, 536, 0, 228, 308, 194, 240, 582, 776, 662, 628, 514,
45 1050, 708},
46 {502, 730, 274, 878, 764, 228, 0, 536, 194, 468, 354, 1004, 890, 856, 514,
47 1278, 480},
48 {194, 354, 810, 502, 388, 308, 536, 0, 342, 388, 730, 468, 354, 320, 662,
49 742, 856},
50 {308, 696, 468, 844, 730, 194, 194, 342, 0, 274, 388, 810, 696, 662, 320,
51 1084, 514},
52 {194, 742, 742, 890, 776, 240, 468, 388, 274, 0, 342, 536, 422, 388, 274,
53 810, 468},
54 {536, 1084, 400, 1232, 1118, 582, 354, 730, 388, 342, 0, 878, 764, 730,
55 388, 1152, 354},
56 {502, 594, 1278, 514, 400, 776, 1004, 468, 810, 536, 878, 0, 114, 308,
57 650, 274, 844},
58 {388, 480, 1164, 628, 514, 662, 890, 354, 696, 422, 764, 114, 0, 194, 536,
59 388, 730},
60 {354, 674, 1130, 822, 708, 628, 856, 320, 662, 388, 730, 308, 194, 0, 342,
61 422, 536},
62 {468, 1016, 788, 1164, 1050, 514, 514, 662, 320, 274, 388, 650, 536, 342,
63 0, 764, 194},
64 {776, 868, 1552, 560, 674, 1050, 1278, 742, 1084, 810, 1152, 274, 388,
65 422, 764, 0, 798},
66 {662, 1210, 754, 1358, 1244, 708, 480, 856, 514, 468, 354, 844, 730, 536,
67 194, 798, 0},
68 };
69 const int num_vehicles = 4;
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71 const std::vector<RoutingIndexManager::NodeIndex> starts{
72 RoutingIndexManager::NodeIndex{1},
73 RoutingIndexManager::NodeIndex{2},
74 RoutingIndexManager::NodeIndex{15},
75 RoutingIndexManager::NodeIndex{16},
76 };
77 const std::vector<RoutingIndexManager::NodeIndex> ends{
78 RoutingIndexManager::NodeIndex{0},
79 RoutingIndexManager::NodeIndex{0},
80 RoutingIndexManager::NodeIndex{0},
81 RoutingIndexManager::NodeIndex{0},
82 };
83
84};
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93void PrintSolution(const DataModel& data, const RoutingIndexManager& manager,
94 const RoutingModel& routing, const Assignment& solution) {
95 int64_t max_route_distance{0};
96 for (int vehicle_id = 0; vehicle_id < data.num_vehicles; ++vehicle_id) {
97 if (!routing.IsVehicleUsed(solution, vehicle_id)) {
98 continue;
99 }
100 int64_t index = routing.Start(vehicle_id);
101 LOG(INFO) << "Route for Vehicle " << vehicle_id << ":";
102 int64_t route_distance{0};
103 std::stringstream route;
104 while (!routing.IsEnd(index)) {
105 route << manager.IndexToNode(index).value() << " -> ";
106 const int64_t previous_index = index;
107 index = solution.Value(routing.NextVar(index));
108 route_distance += routing.GetArcCostForVehicle(previous_index, index,
109 int64_t{vehicle_id});
110 }
111 LOG(INFO) << route.str() << manager.IndexToNode(index).value();
112 LOG(INFO) << "Distance of the route: " << route_distance << "m";
113 max_route_distance = std::max(route_distance, max_route_distance);
114 }
115 LOG(INFO) << "Maximum of the route distances: " << max_route_distance << "m";
116 LOG(INFO) << "";
117 LOG(INFO) << "Problem solved in " << routing.solver()->wall_time() << "ms";
118}
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121void VrpStartsEnds() {
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124 DataModel data;
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129 RoutingIndexManager manager(data.distance_matrix.size(), data.num_vehicles,
130 data.starts, data.ends);
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135 RoutingModel routing(manager);
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140 const int transit_callback_index = routing.RegisterTransitCallback(
141 [&data, &manager](const int64_t from_index,
142 const int64_t to_index) -> int64_t {
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144 const int from_node = manager.IndexToNode(from_index).value();
145 const int to_node = manager.IndexToNode(to_index).value();
146 return data.distance_matrix[from_node][to_node];
147 });
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152 routing.SetArcCostEvaluatorOfAllVehicles(transit_callback_index);
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157 routing.AddDimension(transit_callback_index, 0, 2000,
158 true, "Distance");
159 routing.GetMutableDimension("Distance")->SetGlobalSpanCostCoefficient(100);
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165 searchParameters.set_first_solution_strategy(
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171 const Assignment* solution = routing.SolveWithParameters(searchParameters);
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176 PrintSolution(data, manager, routing, *solution);
177
178}
179}
180
181int main(int , char* []) {
182 operations_research::VrpStartsEnds();
183 return EXIT_SUCCESS;
184}
185
static constexpr Value PATH_CHEAPEST_ARC
int main(int argc, char **argv)
Select next search node to expand Select next item_i to add this new search node to the search Generate a new search node where item_i is not in the knapsack Check validity of this new partial solution(using propagators) - If valid
RoutingSearchParameters DefaultRoutingSearchParameters()
The vehicle routing library lets one model and solve generic vehicle routing problems ranging from th...