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source: branches/ScatterSearch (trunk integration)/HeuristicLab.Algorithms.ScatterSearch/3.3/ScatterSearch.cs @ 8086

Last change on this file since 8086 was 8086, checked in by jkarder, 12 years ago

#1331:

  • synced branch with trunk
  • added custom interface (ISimilarityBasedOperator) to mark operators that conduct similarity calculation
  • similarity calculators are now parameterized by the algorithm
  • deleted SolutionPool2TierUpdateMethod
  • deleted KnapsackMultipleGuidesPathRelinker
  • moved IImprovementOperator, IPathRelinker and ISimilarityCalculator to HeuristicLab.Optimization
  • added parameter descriptions
  • fixed plugin references
  • fixed count of EvaluatedSolutions
  • fixed check for duplicate solutions
  • minor code improvements
File size: 21.9 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2012 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 System;
23using System.Linq;
24using System.Reflection;
25using HeuristicLab.Analysis;
26using HeuristicLab.Common;
27using HeuristicLab.Core;
28using HeuristicLab.Data;
29using HeuristicLab.Operators;
30using HeuristicLab.Optimization;
31using HeuristicLab.Optimization.Operators;
32using HeuristicLab.Parameters;
33using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
34using HeuristicLab.Random;
35using HeuristicLab.Selection;
36
37namespace HeuristicLab.Algorithms.ScatterSearch {
38  /// <summary>
39  /// A scatter search algorithm.
40  /// </summary>
41  [Item("Scatter Search", "A scatter search algorithm.")]
42  [Creatable("Algorithms")]
43  [StorableClass]
44  public sealed class ScatterSearch : HeuristicOptimizationEngineAlgorithm, IStorableContent {
45    public string Filename { get; set; }
46
47    #region Problem Properties
48    public override Type ProblemType {
49      get { return typeof(ISingleObjectiveHeuristicOptimizationProblem); }
50    }
51    public new ISingleObjectiveHeuristicOptimizationProblem Problem {
52      get { return (ISingleObjectiveHeuristicOptimizationProblem)base.Problem; }
53      set { base.Problem = value; }
54    }
55    #endregion
56
57    #region Parameter Properties
58    public IValueParameter<MultiAnalyzer> AnalyzerParameter {
59      get { return (IValueParameter<MultiAnalyzer>)Parameters["Analyzer"]; }
60    }
61    public ConstrainedValueParameter<ICrossover> CrossoverParameter {
62      get { return (ConstrainedValueParameter<ICrossover>)Parameters["Crossover"]; }
63    }
64    public IValueParameter<BoolValue> ExecutePathRelinkingParameter {
65      get { return (IValueLookupParameter<BoolValue>)Parameters["ExecutePathRelinking"]; }
66    }
67    public ConstrainedValueParameter<IImprovementOperator> ImproverParameter {
68      get { return (ConstrainedValueParameter<IImprovementOperator>)Parameters["Improver"]; }
69    }
70    public IValueParameter<IntValue> MaximumIterationsParameter {
71      get { return (IValueParameter<IntValue>)Parameters["MaximumIterations"]; }
72    }
73    public IValueParameter<IntValue> NumberOfHighQualitySolutionsParameter {
74      get { return (IValueParameter<IntValue>)Parameters["NumberOfHighQualitySolutions"]; }
75    }
76    public ConstrainedValueParameter<IPathRelinker> PathRelinkerParameter {
77      get { return (ConstrainedValueParameter<IPathRelinker>)Parameters["PathRelinker"]; }
78    }
79    public IValueParameter<IntValue> PopulationSizeParameter {
80      get { return (IValueParameter<IntValue>)Parameters["PopulationSize"]; }
81    }
82    public IValueParameter<IntValue> ReferenceSetSizeParameter {
83      get { return (IValueParameter<IntValue>)Parameters["ReferenceSetSize"]; }
84    }
85    public IValueParameter<IntValue> SeedParameter {
86      get { return (IValueParameter<IntValue>)Parameters["Seed"]; }
87    }
88    public IValueParameter<BoolValue> SetSeedRandomlyParameter {
89      get { return (IValueParameter<BoolValue>)Parameters["SetSeedRandomly"]; }
90    }
91    public ConstrainedValueParameter<ISimilarityCalculator> SimilarityCalculatorParameter {
92      get { return (ConstrainedValueParameter<ISimilarityCalculator>)Parameters["SimilarityCalculator"]; }
93    }
94    #endregion
95
96    #region Properties
97    private MultiAnalyzer Analyzer {
98      get { return AnalyzerParameter.Value; }
99      set { AnalyzerParameter.Value = value; }
100    }
101    private ICrossover Crossover {
102      get { return CrossoverParameter.Value; }
103      set { CrossoverParameter.Value = value; }
104    }
105    private BoolValue ExecutePathRelinking {
106      get { return ExecutePathRelinkingParameter.Value; }
107      set { ExecutePathRelinkingParameter.Value = value; }
108    }
109    private IImprovementOperator Improver {
110      get { return ImproverParameter.Value; }
111      set { ImproverParameter.Value = value; }
112    }
113    private IntValue MaximumIterations {
114      get { return MaximumIterationsParameter.Value; }
115      set { MaximumIterationsParameter.Value = value; }
116    }
117    private IntValue NumberOfHighQualitySolutions {
118      get { return NumberOfHighQualitySolutionsParameter.Value; }
119      set { NumberOfHighQualitySolutionsParameter.Value = value; }
120    }
121    private IPathRelinker PathRelinker {
122      get { return PathRelinkerParameter.Value; }
123      set { PathRelinkerParameter.Value = value; }
124    }
125    private IntValue PopulationSize {
126      get { return PopulationSizeParameter.Value; }
127      set { PopulationSizeParameter.Value = value; }
128    }
129    private IntValue ReferenceSetSize {
130      get { return ReferenceSetSizeParameter.Value; }
131      set { ReferenceSetSizeParameter.Value = value; }
132    }
133    private IntValue Seed {
134      get { return SeedParameter.Value; }
135      set { SeedParameter.Value = value; }
136    }
137    private BoolValue SetSeedRandomly {
138      get { return SetSeedRandomlyParameter.Value; }
139      set { SetSeedRandomlyParameter.Value = value; }
140    }
141    private ISimilarityCalculator SimilarityCalculator {
142      get { return SimilarityCalculatorParameter.Value; }
143      set { SimilarityCalculatorParameter.Value = value; }
144    }
145    private RandomCreator RandomCreator {
146      get { return (RandomCreator)OperatorGraph.InitialOperator; }
147    }
148    private SolutionsCreator SolutionsCreator {
149      get { return (SolutionsCreator)RandomCreator.Successor; }
150    }
151    private ScatterSearchMainLoop MainLoop {
152      get { return FindMainLoop(SolutionsCreator.Successor); }
153    }
154
155    [Storable]
156    private BestAverageWorstQualityAnalyzer qualityAnalyzer;
157    #endregion
158
159    [StorableConstructor]
160    private ScatterSearch(bool deserializing) : base(deserializing) { }
161    [StorableHook(HookType.AfterDeserialization)]
162    private void AfterDeserialization() {
163      Initialize();
164    }
165    private ScatterSearch(ScatterSearch original, Cloner cloner)
166      : base(original, cloner) {
167      qualityAnalyzer = cloner.Clone(original.qualityAnalyzer);
168      Initialize();
169    }
170    public override IDeepCloneable Clone(Cloner cloner) {
171      return new ScatterSearch(this, cloner);
172    }
173    public ScatterSearch()
174      : base() {
175      #region Create parameters
176      Parameters.Add(new ValueParameter<MultiAnalyzer>("Analyzer", "The analyzer used to analyze each iteration.", new MultiAnalyzer()));
177      Parameters.Add(new ConstrainedValueParameter<ICrossover>("Crossover", "The operator used to cross solutions."));
178      Parameters.Add(new ValueParameter<BoolValue>("ExecutePathRelinking", "True if path relinking should be executed instead of crossover, otherwise false.", new BoolValue(true)));
179      Parameters.Add(new ConstrainedValueParameter<IImprovementOperator>("Improver", "The operator used to improve solutions."));
180      Parameters.Add(new ValueParameter<IntValue>("MaximumIterations", "The maximum number of iterations which should be processed.", new IntValue(100)));
181      Parameters.Add(new ValueParameter<IntValue>("NumberOfHighQualitySolutions", "The number of high quality solutions in the reference set.", new IntValue(5)));
182      Parameters.Add(new ConstrainedValueParameter<IPathRelinker>("PathRelinker", "The operator used to execute path relinking."));
183      Parameters.Add(new ValueParameter<IntValue>("PopulationSize", "The size of the population of solutions.", new IntValue(50)));
184      Parameters.Add(new ValueParameter<IntValue>("ReferenceSetSize", "The size of the reference set.", new IntValue(20)));
185      Parameters.Add(new ValueParameter<IntValue>("Seed", "The random seed used to initialize the new pseudo random number generator.", new IntValue(0)));
186      Parameters.Add(new ValueParameter<BoolValue>("SetSeedRandomly", "True if the random seed should be set to a random value, otherwise false.", new BoolValue(true)));
187      Parameters.Add(new ConstrainedValueParameter<ISimilarityCalculator>("SimilarityCalculator", "The operator used to calculate the similarity between two solutions."));
188      #endregion
189
190      #region Create operators
191      RandomCreator randomCreator = new RandomCreator();
192      SolutionsCreator solutionsCreator = new SolutionsCreator();
193      UniformSubScopesProcessor uniformSubScopesProcessor = new UniformSubScopesProcessor();
194      Placeholder solutionEvaluator = new Placeholder();
195      Placeholder solutionImprover = new Placeholder();
196      VariableCreator variableCreator = new VariableCreator();
197      DataReducer dataReducer = new DataReducer();
198      ResultsCollector resultsCollector = new ResultsCollector();
199      BestSelector bestSelector = new BestSelector();
200      ScatterSearchMainLoop mainLoop = new ScatterSearchMainLoop();
201      #endregion
202
203      #region Create operator graph
204      OperatorGraph.InitialOperator = randomCreator;
205      randomCreator.RandomParameter.ActualName = "Random";
206      randomCreator.SeedParameter.ActualName = SeedParameter.Name;
207      randomCreator.SetSeedRandomlyParameter.ActualName = SetSeedRandomlyParameter.Name;
208      randomCreator.Successor = solutionsCreator;
209
210      solutionsCreator.Name = "DiversificationGenerationMethod";
211      solutionsCreator.NumberOfSolutionsParameter.ActualName = "PopulationSize";
212      solutionsCreator.Successor = uniformSubScopesProcessor;
213
214      uniformSubScopesProcessor.Operator = solutionImprover;
215      uniformSubScopesProcessor.Successor = variableCreator;
216
217      solutionImprover.Name = "SolutionImprover";
218      solutionImprover.OperatorParameter.ActualName = "Improver";
219      solutionImprover.Successor = solutionEvaluator;
220
221      solutionEvaluator.Name = "SolutionEvaluator";
222      solutionEvaluator.OperatorParameter.ActualName = "Evaluator";
223      solutionEvaluator.Successor = null;
224
225      variableCreator.Name = "Initialize EvaluatedSolutions";
226      variableCreator.CollectedValues.Add(new ValueParameter<IntValue>("EvaluatedSolutions", new IntValue()));
227      variableCreator.Successor = dataReducer;
228
229      dataReducer.Name = "Increment EvaluatedSolutions";
230      dataReducer.ParameterToReduce.ActualName = "LocalEvaluatedSolutions";
231      dataReducer.TargetParameter.ActualName = "EvaluatedSolutions";
232      dataReducer.ReductionOperation.Value = new ReductionOperation(ReductionOperations.Sum);
233      dataReducer.TargetOperation.Value = new ReductionOperation(ReductionOperations.Sum);
234      dataReducer.Successor = resultsCollector;
235
236      resultsCollector.Name = "ResultsCollector";
237      resultsCollector.CollectedValues.Add(new LookupParameter<IntValue>("EvaluatedSolutions", null, "EvaluatedSolutions"));
238      resultsCollector.Successor = bestSelector;
239
240      bestSelector.NumberOfSelectedSubScopesParameter.ActualName = NumberOfHighQualitySolutionsParameter.Name;
241      bestSelector.CopySelected = new BoolValue(false);
242      bestSelector.Successor = mainLoop;
243
244      mainLoop.MaximumIterationsParameter.ActualName = MaximumIterationsParameter.Name;
245      mainLoop.RandomParameter.ActualName = randomCreator.RandomParameter.ActualName;
246      mainLoop.ResultsParameter.ActualName = "Results";
247      mainLoop.AnalyzerParameter.ActualName = AnalyzerParameter.Name;
248      mainLoop.IterationsParameter.ActualName = "Iterations";
249      mainLoop.EvaluatedSolutionsParameter.ActualName = "EvaluatedSolutions";
250      mainLoop.CrossoverParameter.ActualName = CrossoverParameter.Name;
251      mainLoop.PopulationSizeParameter.ActualName = PopulationSizeParameter.Name;
252      mainLoop.NumberOfHighQualitySolutionsParameter.ActualName = NumberOfHighQualitySolutionsParameter.Name;
253      mainLoop.Successor = null;
254      #endregion
255
256      qualityAnalyzer = new BestAverageWorstQualityAnalyzer();
257      ParameterizeAnalyzers();
258      UpdateAnalyzers();
259
260      Initialize();
261    }
262
263    public override void Prepare() {
264      if (Problem != null && Improver != null && PathRelinker != null && SimilarityCalculator != null)
265        base.Prepare();
266    }
267
268    #region Events
269    protected override void OnProblemChanged() {
270      ParameterizeStochasticOperator(Problem.SolutionCreator);
271      ParameterizeStochasticOperator(Problem.Evaluator);
272      foreach (IOperator op in Problem.Operators.OfType<IOperator>()) ParameterizeStochasticOperator(op);
273      ParameterizeAnalyzers();
274      ParameterizeSolutionsCreator();
275      ParameterizeBestSelector();
276      UpdateAnalyzers();
277      UpdateCrossovers();
278      UpdatePathRelinkers();
279      UpdateSimilarityCalculators();
280      UpdateImprovers();
281      ParameterizeMainLoop();
282      UpdateSimilarityCalculators();
283      Problem.Evaluator.QualityParameter.ActualNameChanged += new EventHandler(Evaluator_QualityParameter_ActualNameChanged);
284      base.OnProblemChanged();
285    }
286    protected override void Problem_SolutionCreatorChanged(object sender, EventArgs e) {
287      ParameterizeStochasticOperator(Problem.SolutionCreator);
288      ParameterizeSolutionsCreator();
289      base.Problem_SolutionCreatorChanged(sender, e);
290    }
291    protected override void Problem_EvaluatorChanged(object sender, EventArgs e) {
292      ParameterizeStochasticOperator(Problem.Evaluator);
293      ParameterizeSolutionsCreator();
294      ParameterizeMainLoop();
295      ParameterizeAnalyzers();
296      Problem.Evaluator.QualityParameter.ActualNameChanged += new EventHandler(Evaluator_QualityParameter_ActualNameChanged);
297      base.Problem_EvaluatorChanged(sender, e);
298    }
299    protected override void Problem_OperatorsChanged(object sender, EventArgs e) {
300      foreach (IOperator op in Problem.Operators.OfType<IOperator>()) ParameterizeStochasticOperator(op);
301      UpdateAnalyzers();
302      UpdateCrossovers();
303      UpdatePathRelinkers();
304      UpdateSimilarityCalculators();
305      UpdateImprovers();
306      ParameterizeMainLoop();
307      ParameterizeAnalyzers();
308      base.Problem_OperatorsChanged(sender, e);
309    }
310    private void Evaluator_QualityParameter_ActualNameChanged(object sender, EventArgs e) {
311      ParameterizeMainLoop();
312      ParameterizeAnalyzers();
313      ParameterizeBestSelector();
314    }
315    #endregion
316
317    #region Helpers
318    private void Initialize() {
319      if (Problem != null) {
320        Problem.Evaluator.QualityParameter.ActualNameChanged += new EventHandler(Evaluator_QualityParameter_ActualNameChanged);
321      }
322    }
323    private void UpdateAnalyzers() {
324      Analyzer.Operators.Clear();
325      if (Problem != null) {
326        foreach (IAnalyzer analyzer in Problem.Operators.OfType<IAnalyzer>()) {
327          foreach (IScopeTreeLookupParameter param in analyzer.Parameters.OfType<IScopeTreeLookupParameter>())
328            param.Depth = 1;
329          Analyzer.Operators.Add(analyzer, analyzer.EnabledByDefault);
330        }
331      }
332      Analyzer.Operators.Add(qualityAnalyzer, qualityAnalyzer.EnabledByDefault);
333    }
334    private void UpdateCrossovers() {
335      ICrossover oldCrossover = CrossoverParameter.Value;
336      CrossoverParameter.ValidValues.Clear();
337      ICrossover defaultCrossover = Problem.Operators.OfType<ICrossover>().FirstOrDefault();
338
339      foreach (ICrossover crossover in Problem.Operators.OfType<ICrossover>().OrderBy(x => x.Name))
340        CrossoverParameter.ValidValues.Add(crossover);
341
342      if (oldCrossover != null) {
343        ICrossover crossover = CrossoverParameter.ValidValues.FirstOrDefault(x => x.GetType() == oldCrossover.GetType());
344        if (crossover != null) CrossoverParameter.Value = crossover;
345        else oldCrossover = null;
346      }
347      if (oldCrossover == null && defaultCrossover != null)
348        CrossoverParameter.Value = defaultCrossover;
349    }
350    private void UpdateImprovers() {
351      IImprovementOperator oldImprover = ImproverParameter.Value;
352      ImproverParameter.ValidValues.Clear();
353      IImprovementOperator defaultImprover = Problem.Operators.OfType<IImprovementOperator>().FirstOrDefault();
354
355      foreach (IImprovementOperator improver in Problem.Operators.OfType<IImprovementOperator>().OrderBy(x => x.Name))
356        ImproverParameter.ValidValues.Add(improver);
357
358      if (oldImprover != null) {
359        IImprovementOperator improver = ImproverParameter.ValidValues.FirstOrDefault(x => x.GetType() == oldImprover.GetType());
360        if (improver != null) ImproverParameter.Value = improver;
361        else oldImprover = null;
362      }
363      if (oldImprover == null && defaultImprover != null)
364        ImproverParameter.Value = defaultImprover;
365    }
366    private void UpdatePathRelinkers() {
367      IPathRelinker oldPathRelinker = PathRelinkerParameter.Value;
368      PathRelinkerParameter.ValidValues.Clear();
369      IPathRelinker defaultPathRelinker = Problem.Operators.OfType<IPathRelinker>().FirstOrDefault();
370
371      foreach (IPathRelinker pathRelinker in Problem.Operators.OfType<IPathRelinker>().OrderBy(x => x.Name))
372        PathRelinkerParameter.ValidValues.Add(pathRelinker);
373
374      if (oldPathRelinker != null) {
375        IPathRelinker pathRelinker = PathRelinkerParameter.ValidValues.FirstOrDefault(x => x.GetType() == oldPathRelinker.GetType());
376        if (pathRelinker != null) PathRelinkerParameter.Value = pathRelinker;
377        else oldPathRelinker = null;
378      }
379      if (oldPathRelinker == null && defaultPathRelinker != null)
380        PathRelinkerParameter.Value = defaultPathRelinker;
381    }
382    private void UpdateSimilarityCalculators() {
383      ISimilarityCalculator oldDiversityCalculator = SimilarityCalculatorParameter.Value;
384      SimilarityCalculatorParameter.ValidValues.Clear();
385      ISimilarityCalculator defaultDiversityCalculator = Problem.Operators.OfType<ISimilarityCalculator>().FirstOrDefault();
386
387      foreach (ISimilarityCalculator diversityCalculator in Problem.Operators.OfType<ISimilarityCalculator>())
388        SimilarityCalculatorParameter.ValidValues.Add(diversityCalculator);
389
390      if (oldDiversityCalculator != null) {
391        ISimilarityCalculator diversityCalculator = SimilarityCalculatorParameter.ValidValues.FirstOrDefault(x => x.GetType() == oldDiversityCalculator.GetType());
392        if (diversityCalculator != null) SimilarityCalculatorParameter.Value = diversityCalculator;
393        else oldDiversityCalculator = null;
394      }
395      if (oldDiversityCalculator == null && defaultDiversityCalculator != null)
396        SimilarityCalculatorParameter.Value = defaultDiversityCalculator;
397    }
398    private void ParameterizeBestSelector() {
399      OperatorGraph.Operators.OfType<ISingleObjectiveSelector>()
400                             .First().QualityParameter.ActualName = Problem.Evaluator.QualityParameter.ActualName;
401    }
402    private void ParameterizeSolutionsCreator() {
403      SolutionsCreator.EvaluatorParameter.ActualName = Problem.EvaluatorParameter.Name;
404      SolutionsCreator.SolutionCreatorParameter.ActualName = Problem.SolutionCreatorParameter.Name;
405    }
406    private void ParameterizeMainLoop() {
407      if (Problem != null && Improver != null) {
408        MainLoop.BestKnownQualityParameter.ActualName = Problem.BestKnownQualityParameter.Name;
409        MainLoop.MaximizationParameter.ActualName = Problem.MaximizationParameter.Name;
410        MainLoop.QualityParameter.ActualName = Problem.Evaluator.QualityParameter.ActualName;
411        MainLoop.TargetParameter.ActualName = Improver.TargetParameter.ActualName;
412        foreach (var op in MainLoop.OperatorGraph.Operators.OfType<IScatterSearchOperator>()) {
413          // parameter should be accessed direclty (using an interface definition)
414          PropertyInfo propInfo = op.GetType().GetProperty(MainLoop.TargetParameter.Name + "Parameter");
415          if (propInfo != null && propInfo.CanRead)
416            (propInfo.GetValue(op, null) as IValueLookupParameter<IItem>).ActualName = MainLoop.TargetParameter.ActualName;
417          propInfo = op.GetType().GetProperty(MainLoop.QualityParameter.Name + "Parameter");
418          if (propInfo != null && propInfo.CanRead)
419            (propInfo.GetValue(op, null) as IValueLookupParameter<IItem>).ActualName = MainLoop.QualityParameter.ActualName;
420        }
421        foreach (ISimilarityBasedOperator op in MainLoop.OperatorGraph.Operators.OfType<ISimilarityBasedOperator>())
422          op.SimilarityCalculator = SimilarityCalculator;
423      }
424    }
425    private void ParameterizeStochasticOperator(IOperator op) {
426      if (op is IStochasticOperator) {
427        IStochasticOperator stOp = (IStochasticOperator)op;
428        stOp.RandomParameter.ActualName = RandomCreator.RandomParameter.ActualName;
429        stOp.RandomParameter.Hidden = true;
430      }
431    }
432    private void ParameterizeAnalyzers() {
433      qualityAnalyzer.ResultsParameter.ActualName = "Results";
434      qualityAnalyzer.ResultsParameter.Hidden = true;
435      if (Problem != null) {
436        qualityAnalyzer.MaximizationParameter.ActualName = Problem.MaximizationParameter.Name;
437        qualityAnalyzer.MaximizationParameter.Hidden = true;
438        qualityAnalyzer.QualityParameter.Hidden = false;
439        qualityAnalyzer.BestKnownQualityParameter.ActualName = Problem.BestKnownQualityParameter.Name;
440        qualityAnalyzer.BestKnownQualityParameter.Hidden = true;
441      } else {
442        qualityAnalyzer.MaximizationParameter.Hidden = false;
443        qualityAnalyzer.BestKnownQualityParameter.Hidden = false;
444      }
445    }
446    private ScatterSearchMainLoop FindMainLoop(IOperator start) {
447      IOperator mainLoop = start;
448      while (mainLoop != null && !(mainLoop is ScatterSearchMainLoop))
449        mainLoop = ((SingleSuccessorOperator)mainLoop).Successor;
450      return mainLoop as ScatterSearchMainLoop;
451    }
452    #endregion
453  }
454}
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