OptFrame/Heuristic/IteratedLocalSearch.hpp

#ifndef OPTFRAME_ILS_HPP_
#define OPTFRAME_ILS_HPP_

#include <math.h>
#include <vector>

#include "../Heuristic.hpp"
#include "../Evaluator.hpp"

template<class H, class R, class M = OPTFRAME_DEFAULT_MEMORY>
class IteratedLocalSearch: public Heuristic<R, M>
{
protected:
        Evaluator<R, M>& evaluator;

public:

        using Heuristic<R, M>::exec; // prevents name hiding

        IteratedLocalSearch(Evaluator<R, M>& _evaluator) :
                evaluator(_evaluator)
        {
        }

        virtual H& initializeHistory() = 0;

        virtual void localSearch(Solution<R>& s, Evaluation<M>& e, double timelimit, double target_f) = 0;

        virtual void perturbation(Solution<R>& s, Evaluation<M>& e, double timelimit, double target_f, H& history) = 0;

        virtual Solution<R>& acceptanceCriterion(const Solution<R>& s1, const Solution<R>& s2, H& history) = 0;

        virtual bool terminationCondition(H& history) = 0;

        void exec(Solution<R>& s, double timelimit, double target_f)
        {
                Evaluation<M>& e = evaluator.evaluate(s.getR());
                exec(s, e, timelimit, target_f);
                delete &e;
        }

        void exec(Solution<R>& s, Evaluation<M>& e, double timelimit, double target_f)
        {
                cout << "ILS exec(" << target_f << "," << timelimit << ")" << endl;

                Timer tnow;

                H* history = &initializeHistory();

                // 's0' <- GenerateSolution
                // 's*' <- localSearch 's'


                localSearch(s, e, (timelimit - (tnow.now())), target_f);

                Solution<R>* sStar = &s.clone();
                Evaluation<M>* eStar = &e.clone();

                cout << "ILS starts: ";
                e.print();

                do
                {
                        Solution<R>* s1 = &sStar->clone();
                        Evaluation<M>* e1 = &eStar->clone();

                        perturbation(*s1, *e1, (timelimit - (tnow.now())), target_f, *history);

                        localSearch(*s1, *e1, (timelimit - (tnow.now())), target_f);

                        Solution<R>* s2 = s1;
                        Evaluation<M>* e2 = e1;

                        Solution<R>* sStar1 = &acceptanceCriterion(*sStar, *s2, *history);

                        delete sStar;
                        delete eStar;
                        delete s2;
                        delete e2;

                        sStar = sStar1;
                        eStar = &evaluator.evaluate(*sStar);

                } while (evaluator.betterThan(target_f, eStar->evaluation()) && !terminationCondition(*history) && ((tnow.now()) < timelimit));

                e = *eStar;
                s = *sStar;

                delete eStar;
                delete sStar;

                delete history;
        }
};

#endif /*OPTFRAME_ILS_HPP_*/