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source: branches/2707_HeuristicLab.VRPEnhancements/HeuristicLab.Problems.VehicleRouting/3.4/Encodings/Potvin/Crossovers/PotvinSequenceBasedCrossover.cs @ 17010

Last change on this file since 17010 was 17010, checked in by pfleck, 5 years ago

#2707 Merged trunk into branch

File size: 3.8 KB
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1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2019 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 HeuristicLab.Common;
23using HeuristicLab.Core;
24using HEAL.Attic;
25using HeuristicLab.Problems.VehicleRouting.Interfaces;
26
27namespace HeuristicLab.Problems.VehicleRouting.Encodings.Potvin {
28  [Item("PotvinSequenceBasedCrossover", "The SBX crossover for a VRP representations.  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("EFC16985-0308-462C-8D6C-0F1177F53CD2")]
30  public sealed class PotvinSequenceBasedCrossover : PotvinCrossover {
31    [StorableConstructor]
32    private PotvinSequenceBasedCrossover(StorableConstructorFlag _) : base(_) { }
33
34    public PotvinSequenceBasedCrossover()
35      : base() { }
36
37    public override IDeepCloneable Clone(Cloner cloner) {
38      return new PotvinSequenceBasedCrossover(this, cloner);
39    }
40
41    private PotvinSequenceBasedCrossover(PotvinSequenceBasedCrossover original, Cloner cloner)
42      : base(original, cloner) {
43    }
44
45    public static PotvinEncoding Apply(IRandom random, PotvinEncoding parent1, PotvinEncoding parent2, IVRPProblemInstance problemInstance, bool allowInfeasible) {
46      PotvinEncoding child = parent1.Clone() as PotvinEncoding;
47      Tour newTour = new Tour();
48
49      int cities = problemInstance.Cities.Value;
50
51      if (cities > 0) {
52        int breakPoint1 = random.Next(1, cities + 1);
53        Tour tour1 = FindRoute(child, breakPoint1);
54        breakPoint1 = tour1.Stops.IndexOf(breakPoint1);
55
56        for (int i = 0; i < breakPoint1; i++)
57          newTour.Stops.Add(tour1.Stops[i]);
58
59        int breakPoint2 = random.Next(1, cities + 1);
60        Tour tour2 = FindRoute(parent2, breakPoint2);
61        breakPoint2 = tour2.Stops.IndexOf(breakPoint2);
62
63        for (int i = breakPoint2; i < tour2.Stops.Count; i++)
64          newTour.Stops.Add(tour2.Stops[i]);
65
66        int tour1Index = child.Tours.IndexOf(tour1);
67        child.Tours.Remove(tour1);
68        child.Tours.Insert(tour1Index, newTour);
69
70        foreach (int city in tour1.Stops)
71          if (FindRoute(child, city) == null && !child.Unrouted.Contains(city))
72            child.Unrouted.Add(city);
73
74        foreach (int city in tour2.Stops)
75          if (FindRoute(child, city) == null && !child.Unrouted.Contains(city))
76            child.Unrouted.Add(city);
77
78        if (Repair(random, child, newTour, problemInstance, allowInfeasible) || allowInfeasible) {
79          return child;
80        } else {
81          if (random.NextDouble() < 0.5)
82            return parent1.Clone() as PotvinEncoding;
83          else
84            return parent2.Clone() as PotvinEncoding;
85        }
86      } else {
87        return child;
88      }
89    }
90
91    protected override PotvinEncoding Crossover(IRandom random, PotvinEncoding parent1, PotvinEncoding parent2) {
92      return Apply(random, parent1, parent2, ProblemInstance, AllowInfeasibleSolutions.Value.Value);
93    }
94  }
95}
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