source: branches/VRP/HeuristicLab.Problems.VehicleRouting/3.3/Encodings/Alba/Moves/LambdaInterchange/StochasticLambdaInterchangeSingleMoveGenerator.cs @ 4287

#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2010 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
 *
 * This file is part of HeuristicLab.
 *
 * HeuristicLab is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
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 * HeuristicLab is distributed in the hope that it will be useful,
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 * GNU General Public License for more details.
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 * You should have received a copy of the GNU General Public License
 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
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#endregion

using System;
using HeuristicLab.Core;
using HeuristicLab.Optimization;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
using HeuristicLab.Problems.VehicleRouting.Encodings.Alba;
using HeuristicLab.Parameters;
using System.Collections.Generic;
using HeuristicLab.Problems.VehicleRouting.Encodings.General;

namespace HeuristicLab.Problems.VehicleRouting.Encodings.Alba {
  [Item("StochasticLambdaInterchangeSingleMoveGenerator", "Generates one random lambda interchange move from a given VRP encoding.")]
  [StorableClass]
  public sealed class StochasticLambdaInterchangeSingleMoveGenerator : LambdaInterchangeMoveGenerator,
    IStochasticOperator, ISingleMoveGenerator, IAlbaLambdaInterchangeMoveOperator, IMultiVRPMoveGenerator {
    #region IMultiVRPMoveOperator Members

    public ILookupParameter VRPMoveParameter {
      get { return (ILookupParameter)Parameters["LambdaInterchangeMove"]; }
    }

    #endregion
    
    public ILookupParameter<IRandom> RandomParameter {
      get { return (ILookupParameter<IRandom>)Parameters["Random"]; }
    }
    
    [StorableConstructor]
    private StochasticLambdaInterchangeSingleMoveGenerator(bool deserializing) : base(deserializing) { }

    public StochasticLambdaInterchangeSingleMoveGenerator()
      : base() {
        Parameters.Add(new LookupParameter<IRandom>("Random", "The random number generator."));
    }

    public static LambdaInterchangeMove Apply(AlbaEncoding individual, int cities, int lambda, IRandom rand) {
      List<Tour> tours = individual.GetTours();

      int route1Index = rand.Next(tours.Count);
      Tour route1 = tours[route1Index];

      int route2Index = rand.Next(tours.Count - 1);
      if (route2Index >= route1Index)
        route2Index += 1;
      Tour route2 = tours[route2Index];

      int length1 = rand.Next(Math.Min(lambda + 1, route1.Cities.Count + 1));
      int index1 = rand.Next(route1.Cities.Count - length1 + 1);

      int l2Min = 0;
      if (length1 == 0)
        l2Min = 1;
      int length2 = rand.Next(l2Min, Math.Min(lambda + 1, route2.Cities.Count + 1));
      int index2 = rand.Next(route2.Cities.Count - length2 + 1);

      return new LambdaInterchangeMove(route1Index, index1, length1, route2Index, index2, length2, individual);
    }

    protected override LambdaInterchangeMove[] GenerateMoves(AlbaEncoding individual, int lambda) {
      List<LambdaInterchangeMove> moves = new List<LambdaInterchangeMove>();

      LambdaInterchangeMove move = Apply(individual, Cities, lambda, RandomParameter.ActualValue);
      if(move != null)
        moves.Add(move);

      return moves.ToArray();
    }
  }
}