source: trunk/sources/HeuristicLab.Encodings.Permutation/3.3/Moves/ExhaustiveTwoOptMoveGenerator.cs @ 3026

#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
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HeuristicLab is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
 */
#endregion

using System;
using HeuristicLab.Core;
using HeuristicLab.Operators;
using HeuristicLab.Parameters;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

namespace HeuristicLab.Encodings.Permutation {
  [Item("ExhaustiveTwoOptMoveGenerator", "Generates all possible 2-opt moves from a given permutation.")]
  [StorableClass]
  public class ExhaustiveTwoOptMoveGenerator : SingleSuccessorOperator, IPermutationMoveGenerator {
    public ILookupParameter<Permutation> PermutationParameter {
      get { return (ILookupParameter<Permutation>)Parameters["Permutation"]; }
    }
    public LookupParameter<TwoOptMove> MoveParameter {
      get { return (LookupParameter<TwoOptMove>)Parameters["Move"]; }
    }
    private ScopeParameter CurrentScopeParameter {
      get { return (ScopeParameter)Parameters["CurrentScope"]; }
    }

    public ExhaustiveTwoOptMoveGenerator()
      : base() {
      Parameters.Add(new LookupParameter<Permutation>("Permutation", "The permutation for which moves should be generated."));
      Parameters.Add(new LookupParameter<TwoOptMove>("Move", "The moves that should be generated in subscopes."));
      Parameters.Add(new ScopeParameter("CurrentScope", "The current scope where the moves should be added as subscopes."));
    }

    public override IOperation Apply() {
      Permutation p = PermutationParameter.ActualValue;
      int length = p.Length;
      int totalMoves = (length) * (length - 1) / 2 - 3;
      Scope[] moveScopes = new Scope[totalMoves];
      int count = 0;
      for (int i = 0; i < length - 1; i++)
        for (int j = i + 1; j < length; j++) {
          // doesn't make sense to inverse the whole permutation or the whole but one
          if (i == 0 && j >= length - 2) continue;
          else if (i == 1 && j >= length - 1) continue;
          Scope s = new Scope(count.ToString());
          s.Variables.Add(new Variable(MoveParameter.ActualName, new TwoOptMove(i, j)));
          moveScopes[count] = s;
          count++;
        }
      // FIXME: remove the line below
      if (count != totalMoves) throw new InvalidOperationException(Name + ": totalMoves != count");
      CurrentScopeParameter.ActualValue.SubScopes.AddRange(moveScopes);
      return base.Apply();
    }
  }
}