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DotNet Reference

VrpInitialRoutes.cs
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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 InitialRoutes {
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  // [START initial_routes]
47  public long[][] InitialRoutes = {
48  new long[] {8, 16, 14, 13, 12, 11},
49  new long[] {3, 4, 9, 10},
50  new long[] {15, 1},
51  new long[] {7, 5, 2, 6},
52  };
53  // [END initial_routes]
54  public int VehicleNumber = 4;
55  public int Depot = 0;
56  };
57  // [END data_model]
58 
59  // [START solution_printer]
63  static void PrintSolution(
64  in DataModel data,
65  in RoutingModel routing,
66  in RoutingIndexManager manager,
67  in Assignment solution) {
68  // Inspect solution.
69  long maxRouteDistance = 0;
70  for (int i = 0; i < data.VehicleNumber; ++i) {
71  Console.WriteLine("Route for Vehicle {0}:", i);
72  long routeDistance = 0;
73  var index = routing.Start(i);
74  while (routing.IsEnd(index) == false) {
75  Console.Write("{0} -> ", manager.IndexToNode((int)index));
76  var previousIndex = index;
77  index = solution.Value(routing.NextVar(index));
78  routeDistance += routing.GetArcCostForVehicle(previousIndex, index, 0);
79  }
80  Console.WriteLine("{0}", manager.IndexToNode((int)index));
81  Console.WriteLine("Distance of the route: {0}", routeDistance);
82  maxRouteDistance = Math.Max(routeDistance, maxRouteDistance);
83  }
84  Console.WriteLine("Maximum distance of the routes: {0}", maxRouteDistance);
85  }
86  // [END solution_printer]
87 
88  public static void Main(String[] args) {
89  // Instantiate the data problem.
90  // [START data]
91  DataModel data = new DataModel();
92  // [END data]
93 
94  // Create Routing Index Manager
95  // [START index_manager]
97  data.DistanceMatrix.GetLength(0),
98  data.VehicleNumber,
99  data.Depot);
100  // [END index_manager]
101 
102  // Create Routing Model.
103  // [START routing_model]
104  RoutingModel routing = new RoutingModel(manager);
105  // [END routing_model]
106 
107  // Create and register a transit callback.
108  // [START transit_callback]
109  int transitCallbackIndex = routing.RegisterTransitCallback(
110  (long fromIndex, long toIndex) => {
111  // Convert from routing variable Index to distance matrix NodeIndex.
112  var fromNode = manager.IndexToNode(fromIndex);
113  var toNode = manager.IndexToNode(toIndex);
114  return data.DistanceMatrix[fromNode, toNode]; }
115  );
116  // [END transit_callback]
117 
118  // Define cost of each arc.
119  // [START arc_cost]
120  routing.SetArcCostEvaluatorOfAllVehicles(transitCallbackIndex);
121  // [END arc_cost]
122 
123  // Add Distance constraint.
124  // [START distance_constraint]
125  routing.AddDimension(transitCallbackIndex, 0, 3000,
126  true, // start cumul to zero
127  "Distance");
128  RoutingDimension distanceDimension = routing.GetMutableDimension("Distance");
129  distanceDimension.SetGlobalSpanCostCoefficient(100);
130  // [END distance_constraint]
131 
132  // Get inital solution from routes.
133  // [START print_initial_solution]
134  Assignment initialSolution = routing.ReadAssignmentFromRoutes(
135  data.InitialRoutes, true);
136  // Print initial solution on console.
137  Console.WriteLine("Initial solution:");
138  PrintSolution(data, routing, manager, initialSolution);
139  // [END print_initial_solution]
140 
141  // Setting first solution heuristic.
142  // [START parameters]
143  RoutingSearchParameters searchParameters =
145  // [END parameters]
146 
147  // Solve the problem.
148  // [START solve]
149  Assignment solution = routing.SolveWithParameters(searchParameters);
150  // [END solve]
151 
152  // Print solution on console.
153  // [START print_solution]
154  Console.WriteLine("Solution after search:");
155  PrintSolution(data, routing, manager, solution);
156  // [END print_solution]
157  }
158 }
159 // [END program]
void SetArcCostEvaluatorOfAllVehicles(int evaluator_index)
Definition: Assignment.cs:11
int IndexToNode(long index)
Definition: RoutingModel.cs:18
static void Main(String[] args)
VRP with initial routes.
Assignment ReadAssignmentFromRoutes(long[][] routes, bool ignore_inactive_indices)
void SetGlobalSpanCostCoefficient(long coefficient)
bool AddDimension(int evaluator_index, long slack_max, long capacity, bool fix_start_cumul_to_zero, string name)
static Google.OrTools.ConstraintSolver.RoutingSearchParameters DefaultRoutingSearchParameters()
Definition: Assignment.cs:18
int RegisterTransitCallback(LongLongToLong callback)
Assignment SolveWithParameters(Google.OrTools.ConstraintSolver.RoutingSearchParameters search_parameters)
RoutingDimension GetMutableDimension(string dimension_name)
Parameters defining the search used to solve vehicle routing problems.