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DotNet Reference

VrpDropNodes.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 VrpDropNodes {
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 demands_capacities]
47  public long[] Demands = {0, 1, 1, 3, 6, 3, 6, 8, 8, 1, 2, 1, 2, 6, 6, 8, 8};
48  public long[] VehicleCapacities = {15, 15, 15, 15};
49  // [END demands_capacities]
50  public int VehicleNumber = 4;
51  public int Depot = 0;
52  };
53  // [END data_model]
54 
55  // [START solution_printer]
59  static void PrintSolution(
60  in DataModel data,
61  in RoutingModel routing,
62  in RoutingIndexManager manager,
63  in Assignment solution) {
64  // Display dropped nodes.
65  string droppedNodes = "Dropped nodes:";
66  for (int index = 0; index < routing.Size(); ++index) {
67  if (routing.IsStart(index) || routing.IsEnd(index)) {
68  continue;
69  }
70  if (solution.Value(routing.NextVar(index)) == index) {
71  droppedNodes += " " + manager.IndexToNode(index);
72  }
73  }
74  Console.WriteLine("{0}", droppedNodes);
75  // Inspect solution.
76  long totalDistance = 0;
77  long totalLoad = 0;
78  for (int i = 0; i < data.VehicleNumber; ++i) {
79  Console.WriteLine("Route for Vehicle {0}:", i);
80  long routeDistance = 0;
81  long routeLoad = 0;
82  var index = routing.Start(i);
83  while (routing.IsEnd(index) == false) {
84  long nodeIndex = manager.IndexToNode(index);
85  routeLoad += data.Demands[nodeIndex];
86  Console.Write("{0} Load({1}) -> ", nodeIndex, routeLoad);
87  var previousIndex = index;
88  index = solution.Value(routing.NextVar(index));
89  routeDistance += routing.GetArcCostForVehicle(previousIndex, index, 0);
90  }
91  Console.WriteLine("{0}", manager.IndexToNode((int)index));
92  Console.WriteLine("Distance of the route: {0}m", routeDistance);
93  totalDistance += routeDistance;
94  totalLoad += routeLoad;
95  }
96  Console.WriteLine("Total Distance of all routes: {0}m", totalDistance);
97  Console.WriteLine("Total Load of all routes: {0}m", totalLoad);
98  }
99  // [END solution_printer]
100 
101  public static void Main(String[] args) {
102  // Instantiate the data problem.
103  // [START data]
104  DataModel data = new DataModel();
105  // [END data]
106 
107  // Create Routing Index Manager
108  // [START index_manager]
110  data.DistanceMatrix.GetLength(0),
111  data.VehicleNumber,
112  data.Depot);
113  // [END index_manager]
114 
115  // Create Routing Model.
116  // [START routing_model]
117  RoutingModel routing = new RoutingModel(manager);
118  // [END routing_model]
119 
120  // Create and register a transit callback.
121  // [START transit_callback]
122  int transitCallbackIndex = routing.RegisterTransitCallback(
123  (long fromIndex, long toIndex) => {
124  // Convert from routing variable Index to distance matrix NodeIndex.
125  var fromNode = manager.IndexToNode(fromIndex);
126  var toNode = manager.IndexToNode(toIndex);
127  return data.DistanceMatrix[fromNode, toNode]; }
128  );
129  // [END transit_callback]
130 
131  // Define cost of each arc.
132  // [START arc_cost]
133  routing.SetArcCostEvaluatorOfAllVehicles(transitCallbackIndex);
134  // [END arc_cost]
135 
136  // Add Capacity constraint.
137  // [START capacity_constraint]
138  int demandCallbackIndex = routing.RegisterUnaryTransitCallback(
139  (long fromIndex) => {
140  // Convert from routing variable Index to demand NodeIndex.
141  var fromNode = manager.IndexToNode(fromIndex);
142  return data.Demands[fromNode]; }
143  );
145  demandCallbackIndex, 0, // null capacity slack
146  data.VehicleCapacities, // vehicle maximum capacities
147  true, // start cumul to zero
148  "Capacity");
149  // Allow to drop nodes.
150  long penalty = 1000;
151  for (int i = 1; i < data.DistanceMatrix.GetLength(0); ++i) {
152  routing.AddDisjunction(
153  new long[] {manager.NodeToIndex(i)}, penalty);
154  }
155  // [END capacity_constraint]
156 
157  // Setting first solution heuristic.
158  // [START parameters]
159  RoutingSearchParameters searchParameters =
161  searchParameters.FirstSolutionStrategy =
162  FirstSolutionStrategy.Types.Value.PathCheapestArc;
163  // [END parameters]
164 
165  // Solve the problem.
166  // [START solve]
167  Assignment solution = routing.SolveWithParameters(searchParameters);
168  // [END solve]
169 
170  // Print solution on console.
171  // [START print_solution]
172  PrintSolution(data, routing, manager, solution);
173  // [END print_solution]
174  }
175 }
176 // [END program]
void SetArcCostEvaluatorOfAllVehicles(int evaluator_index)
static void Main(String[] args)
global::Google.OrTools.ConstraintSolver.FirstSolutionStrategy.Types.Value FirstSolutionStrategy
First solution strategies, used as starting point of local search.
long NodeToIndex(int node)
Definition: Assignment.cs:11
int IndexToNode(long index)
Value
Definition: RoutingModel.cs:18
First solution strategies, used as starting point of local search.
Minimal Vrp with drop nodes.
Definition: VrpDropNodes.cs:24
int RegisterUnaryTransitCallback(LongToLong callback)
static Google.OrTools.ConstraintSolver.RoutingSearchParameters DefaultRoutingSearchParameters()
Definition: Assignment.cs:18
bool AddDimensionWithVehicleCapacity(int evaluator_index, long slack_max, long[] vehicle_capacities, bool fix_start_cumul_to_zero, string name)
int AddDisjunction(long[] indices, long penalty, long max_cardinality)
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.