DotNet Reference

DotNet Reference

Vrp.cs
Go to the documentation of this file.
1 // Copyright 2010-2018 Google LLC
2 // Licensed under the Apache License, Version 2.0 (the "License");
3 // you may not use this file except in compliance with the License.
4 // You may obtain a copy of the License at
5 //
6 // http://www.apache.org/licenses/LICENSE-2.0
7 //
8 // Unless required by applicable law or agreed to in writing, software
9 // distributed under the License is distributed on an "AS IS" BASIS,
10 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11 // See the License for the specific language governing permissions and
12 // limitations under the License.
13 
14 // [START program]
15 // [START import]
16 using System;
17 using System.Collections.Generic;
19 // [END import]
20 
24 public class Vrp {
25  // [START data_model]
26  class DataModel {
27  public long[,] DistanceMatrix = {
28  {0, 548, 776, 696, 582, 274, 502, 194, 308, 194, 536, 502, 388, 354, 468, 776, 662},
29  {548, 0, 684, 308, 194, 502, 730, 354, 696, 742, 1084, 594, 480, 674, 1016, 868, 1210},
30  {776, 684, 0, 992, 878, 502, 274, 810, 468, 742, 400, 1278, 1164, 1130, 788, 1552, 754},
31  {696, 308, 992, 0, 114, 650, 878, 502, 844, 890, 1232, 514, 628, 822, 1164, 560, 1358},
32  {582, 194, 878, 114, 0, 536, 764, 388, 730, 776, 1118, 400, 514, 708, 1050, 674, 1244},
33  {274, 502, 502, 650, 536, 0, 228, 308, 194, 240, 582, 776, 662, 628, 514, 1050, 708},
34  {502, 730, 274, 878, 764, 228, 0, 536, 194, 468, 354, 1004, 890, 856, 514, 1278, 480},
35  {194, 354, 810, 502, 388, 308, 536, 0, 342, 388, 730, 468, 354, 320, 662, 742, 856},
36  {308, 696, 468, 844, 730, 194, 194, 342, 0, 274, 388, 810, 696, 662, 320, 1084, 514},
37  {194, 742, 742, 890, 776, 240, 468, 388, 274, 0, 342, 536, 422, 388, 274, 810, 468},
38  {536, 1084, 400, 1232, 1118, 582, 354, 730, 388, 342, 0, 878, 764, 730, 388, 1152, 354},
39  {502, 594, 1278, 514, 400, 776, 1004, 468, 810, 536, 878, 0, 114, 308, 650, 274, 844},
40  {388, 480, 1164, 628, 514, 662, 890, 354, 696, 422, 764, 114, 0, 194, 536, 388, 730},
41  {354, 674, 1130, 822, 708, 628, 856, 320, 662, 388, 730, 308, 194, 0, 342, 422, 536},
42  {468, 1016, 788, 1164, 1050, 514, 514, 662, 320, 274, 388, 650, 536, 342, 0, 764, 194},
43  {776, 868, 1552, 560, 674, 1050, 1278, 742, 1084, 810, 1152, 274, 388, 422, 764, 0, 798},
44  {662, 1210, 754, 1358, 1244, 708, 480, 856, 514, 468, 354, 844, 730, 536, 194, 798, 0}
45  };
46  public int VehicleNumber = 4;
47  public int Depot = 0;
48  };
49  // [END data_model]
50 
51  // [START solution_printer]
55  static void PrintSolution(
56  in DataModel data,
57  in RoutingModel routing,
58  in RoutingIndexManager manager,
59  in Assignment solution) {
60  Console.WriteLine("Objective: {0}", solution.ObjectiveValue());
61  // Inspect solution.
62  long totalDistance = 0;
63  for (int i = 0; i < data.VehicleNumber; ++i) {
64  Console.WriteLine("Route for Vehicle {0}:", i);
65  long routeDistance = 0;
66  var index = routing.Start(i);
67  while (routing.IsEnd(index) == false) {
68  Console.Write("{0} -> ", manager.IndexToNode((int)index));
69  var previousIndex = index;
70  index = solution.Value(routing.NextVar(index));
71  routeDistance += routing.GetArcCostForVehicle(previousIndex, index, 0);
72  }
73  Console.WriteLine("{0}", manager.IndexToNode((int)index));
74  Console.WriteLine("Distance of the route: {0}m", routeDistance);
75  totalDistance += routeDistance;
76  }
77  Console.WriteLine("Total Distance of all routes: {0}m", totalDistance);
78  }
79  // [END solution_printer]
80 
81  public static void Main(String[] args) {
82  // Instantiate the data problem.
83  // [START data]
84  DataModel data = new DataModel();
85  // [END data]
86 
87  // Create Routing Index Manager
88  // [START index_manager]
90  data.DistanceMatrix.GetLength(0),
91  data.VehicleNumber,
92  data.Depot);
93  // [END index_manager]
94 
95  // Create Routing Model.
96  // [START routing_model]
97  RoutingModel routing = new RoutingModel(manager);
98  // [END routing_model]
99 
100  // Create and register a transit callback.
101  // [START transit_callback]
102  int transitCallbackIndex = routing.RegisterTransitCallback(
103  (long fromIndex, long toIndex) => {
104  // Convert from routing variable Index to distance matrix NodeIndex.
105  var fromNode = manager.IndexToNode(fromIndex);
106  var toNode = manager.IndexToNode(toIndex);
107  return data.DistanceMatrix[fromNode, toNode]; }
108  );
109  // [END transit_callback]
110 
111  // Define cost of each arc.
112  // [START arc_cost]
113  routing.SetArcCostEvaluatorOfAllVehicles(transitCallbackIndex);
114  // [END arc_cost]
115 
116  // Setting first solution heuristic.
117  // [START parameters]
118  RoutingSearchParameters searchParameters =
120  searchParameters.FirstSolutionStrategy =
121  FirstSolutionStrategy.Types.Value.PathCheapestArc;
122  // [END parameters]
123 
124  // Solve the problem.
125  // [START solve]
126  Assignment solution = routing.SolveWithParameters(searchParameters);
127  // [END solve]
128 
129  // Print solution on console.
130  // [START print_solution]
131  PrintSolution(data, routing, manager, solution);
132  // [END print_solution]
133  }
134 }
135 // [END program]
void SetArcCostEvaluatorOfAllVehicles(int evaluator_index)
global::Google.OrTools.ConstraintSolver.FirstSolutionStrategy.Types.Value FirstSolutionStrategy
First solution strategies, used as starting point of local search.
Minimal TSP using distance matrix.
Definition: Vrp.cs:24
Definition: Assignment.cs:11
int IndexToNode(long index)
Value
Definition: RoutingModel.cs:18
static void Main(String[] args)
Definition: Vrp.cs:81
First solution strategies, used as starting point of local search.
static Google.OrTools.ConstraintSolver.RoutingSearchParameters DefaultRoutingSearchParameters()
Definition: Assignment.cs:18
Container for nested types declared in the FirstSolutionStrategy message type.
int RegisterTransitCallback(LongLongToLong callback)
Assignment SolveWithParameters(Google.OrTools.ConstraintSolver.RoutingSearchParameters search_parameters)
Parameters defining the search used to solve vehicle routing problems.