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source: branches/2521_ProblemRefactoring/HeuristicLab.Problems.VehicleRouting/3.4/Encodings/Potvin/Manipulators/PotvinTwoLevelExchangeManipulator.cs @ 17712

Last change on this file since 17712 was 17712, checked in by abeham, 4 years ago

#2521: working on VRP

File size: 4.2 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) Heuristic and Evolutionary Algorithms Laboratory (HEAL)
4 *
5 * This file is part of HeuristicLab.
6 *
7 * HeuristicLab is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, either version 3 of the License, or
10 * (at your option) any later version.
11 *
12 * HeuristicLab is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
19 */
20#endregion
21
22using HEAL.Attic;
23using HeuristicLab.Common;
24using HeuristicLab.Core;
25using HeuristicLab.Problems.VehicleRouting.Interfaces;
26
27namespace HeuristicLab.Problems.VehicleRouting.Encodings.Potvin {
28  [Item("PotvinTwoLevelExchangeManipulator", "The 2M operator which manipulates a VRP representation.  It is implemented as described in Potvin, J.-Y. and Bengio, S. (1996). The Vehicle Routing Problem with Time Windows - Part II: Genetic Search. INFORMS Journal of Computing, 8:165–172.")]
29  [StorableType("FB992182-9FD8-4B08-A48C-97378E85DAD5")]
30  public sealed class PotvinTwoLevelExchangeManipulator : PotvinManipulator {
31    [StorableConstructor]
32    private PotvinTwoLevelExchangeManipulator(StorableConstructorFlag _) : base(_) { }
33
34    public PotvinTwoLevelExchangeManipulator() : base() { }
35
36    public override IDeepCloneable Clone(Cloner cloner) {
37      return new PotvinTwoLevelExchangeManipulator(this, cloner);
38    }
39
40    private PotvinTwoLevelExchangeManipulator(PotvinTwoLevelExchangeManipulator original, Cloner cloner)
41      : base(original, cloner) {
42    }
43
44    public static void ApplyManipulation(IRandom random, PotvinEncodedSolution individual, IVRPProblemInstance instance, bool allowInfeasible) {
45      int selectedIndex = SelectRandomTourBiasedByLength(random, individual, instance);
46      if (selectedIndex >= 0) {
47        Tour route1 = individual.Tours[selectedIndex];
48
49        bool performed = false;
50        int customer1Position = 0;
51        while (customer1Position < route1.Stops.Count) {
52          performed = false;
53
54          foreach (Tour tour in individual.Tours) {
55            if (tour != route1) {
56              for (int customer2Position = 0; customer2Position < tour.Stops.Count; customer2Position++) {
57                int customer1 = route1.Stops[customer1Position];
58                int customer2 = tour.Stops[customer2Position];
59
60                //customer1 can be feasibly inserted at the location of customer2
61                tour.Stops[customer2Position] = customer1;
62                route1.Stops.RemoveAt(customer1Position);
63
64                var tourEval = instance.EvaluateTour(tour, individual);
65                if (tourEval.IsFeasible) {
66                  int routeIdx, place;
67                  if (FindInsertionPlace(individual,
68                    customer2, selectedIndex, allowInfeasible, out routeIdx, out place)) {
69                    individual.Tours[routeIdx].Stops.Insert(place, customer2);
70
71                    //two-level exchange has been performed
72                    performed = true;
73                    break;
74                  } else {
75                    tour.Stops[customer2Position] = customer2;
76                    route1.Stops.Insert(customer1Position, customer1);
77                  }
78                } else {
79                  tour.Stops[customer2Position] = customer2;
80                  route1.Stops.Insert(customer1Position, customer1);
81                }
82              }
83            }
84
85            if (performed)
86              break;
87          }
88
89          if (!performed)
90            customer1Position++;
91        }
92      }
93    }
94     
95
96    protected override void Manipulate(IRandom random, PotvinEncodedSolution individual) {
97      bool allowInfeasible = AllowInfeasibleSolutions.Value.Value;
98
99      ApplyManipulation(random, individual, ProblemInstance, allowInfeasible);
100    }
101  }
102}
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