CbcHeuristicLocal.hpp

/* $Id: CbcHeuristicLocal.hpp 1802 2012-11-21 09:38:56Z forrest $ */
// Copyright (C) 2002, International Business Machines
// Corporation and others.  All Rights Reserved.
// This code is licensed under the terms of the Eclipse Public License (EPL).

#ifndef CbcHeuristicLocal_H
#define CbcHeuristicLocal_H

#include "CbcHeuristic.hpp"
/** LocalSearch class
 */

class CbcHeuristicLocal : public CbcHeuristic {
public:

    // Default Constructor
    CbcHeuristicLocal ();

    /* Constructor with model - assumed before cuts
       Initial version does not do Lps
    */
    CbcHeuristicLocal (CbcModel & model);

    // Copy constructor
    CbcHeuristicLocal ( const CbcHeuristicLocal &);

    // Destructor
    ~CbcHeuristicLocal ();

    /// Clone
    virtual CbcHeuristic * clone() const;

    /// Assignment operator
    CbcHeuristicLocal & operator=(const CbcHeuristicLocal& rhs);

    /// Create C++ lines to get to current state
    virtual void generateCpp( FILE * fp) ;

    /// Resets stuff if model changes
    virtual void resetModel(CbcModel * model);

    /// update model (This is needed if cliques update matrix etc)
    virtual void setModel(CbcModel * model);

    using CbcHeuristic::solution ;
    /** returns 0 if no solution, 1 if valid solution.
        Sets solution values if good, sets objective value (only if good)
        This is called after cuts have been added - so can not add cuts
        First tries setting a variable to better value.  If feasible then
        tries setting others.  If not feasible then tries swaps

        ********

        This first version does not do LP's and does swaps of two integer
        variables.  Later versions could do Lps.
    */
    virtual int solution(double & objectiveValue,
                         double * newSolution);
    /// This version fixes stuff and does IP
    int solutionFix(double & objectiveValue,
                    double * newSolution,
                    const int * keep);

    /// Sets type of search
    inline void setSearchType(int value) {
        swap_ = value;
    }
    /// Used array so we can set
    inline int * used() const {
        return used_;
    }

protected:
    // Data

    // Original matrix by column
    CoinPackedMatrix matrix_;

    // Number of solutions so we only do after new solution
    int numberSolutions_;
    // Type of search 0=normal, 1=BAB
    int swap_;
    /// Whether a variable has been in a solution (also when)
    int * used_;
};

/** Proximity Search class
 */
class CbcHeuristicFPump;
class CbcHeuristicProximity : public CbcHeuristic {
public:

    // Default Constructor
    CbcHeuristicProximity ();

    /* Constructor with model - assumed before cuts
    */
    CbcHeuristicProximity (CbcModel & model);

    // Copy constructor
    CbcHeuristicProximity ( const CbcHeuristicProximity &);

    // Destructor
    ~CbcHeuristicProximity ();

    /// Clone
    virtual CbcHeuristic * clone() const;

    /// Assignment operator
    CbcHeuristicProximity & operator=(const CbcHeuristicProximity& rhs);

    /// Create C++ lines to get to current state
    virtual void generateCpp( FILE * fp) ;

    /// Resets stuff if model changes
    virtual void resetModel(CbcModel * model);

    /// update model (This is needed if cliques update matrix etc)
    virtual void setModel(CbcModel * model);

    using CbcHeuristic::solution ;
    /** returns 0 if no solution, 1 if valid solution.
        Sets solution values if good, sets objective value (only if good)
    */
    virtual int solution(double & objectiveValue,
                         double * newSolution);

    /// Used array so we can set
    inline int * used() const {
        return used_;
    }

protected:
    // Data
    // Copy of Feasibility pump
    CbcHeuristicFPump * feasibilityPump_;
    // Number of solutions so we only do after new solution
    int numberSolutions_;
    /// Whether a variable has been in a solution (also when)
    int * used_;
};


/** Naive class
    a) Fix all ints as close to zero as possible
    b) Fix all ints with nonzero costs and < large to zero
    c) Put bounds round continuous and UIs and maximize
 */

class CbcHeuristicNaive : public CbcHeuristic {
public:

    // Default Constructor
    CbcHeuristicNaive ();

    /* Constructor with model - assumed before cuts
       Initial version does not do Lps
    */
    CbcHeuristicNaive (CbcModel & model);

    // Copy constructor
    CbcHeuristicNaive ( const CbcHeuristicNaive &);

    // Destructor
    ~CbcHeuristicNaive ();

    /// Clone
    virtual CbcHeuristic * clone() const;

    /// Assignment operator
    CbcHeuristicNaive & operator=(const CbcHeuristicNaive& rhs);

    /// Create C++ lines to get to current state
    virtual void generateCpp( FILE * fp) ;

    /// Resets stuff if model changes
    virtual void resetModel(CbcModel * model);

    /// update model (This is needed if cliques update matrix etc)
    virtual void setModel(CbcModel * model);

    using CbcHeuristic::solution ;
    /** returns 0 if no solution, 1 if valid solution.
        Sets solution values if good, sets objective value (only if good)
    */
    virtual int solution(double & objectiveValue,
                         double * newSolution);

    /// Sets large cost value
    inline void setLargeValue(double value) {
        large_ = value;
    }
    /// Gets large cost value
    inline double largeValue() const {
        return large_;
    }

protected:
    /// Data
    /// Large value
    double large_;
};

/** Crossover Search class
 */

class CbcHeuristicCrossover : public CbcHeuristic {
public:

    // Default Constructor
    CbcHeuristicCrossover ();

    /* Constructor with model - assumed before cuts
       Initial version does not do Lps
    */
    CbcHeuristicCrossover (CbcModel & model);

    // Copy constructor
    CbcHeuristicCrossover ( const CbcHeuristicCrossover &);

    // Destructor
    ~CbcHeuristicCrossover ();

    /// Clone
    virtual CbcHeuristic * clone() const;

    /// Assignment operator
    CbcHeuristicCrossover & operator=(const CbcHeuristicCrossover& rhs);

    /// Create C++ lines to get to current state
    virtual void generateCpp( FILE * fp) ;

    /// Resets stuff if model changes
    virtual void resetModel(CbcModel * model);

    /// update model (This is needed if cliques update matrix etc)
    virtual void setModel(CbcModel * model);

    using CbcHeuristic::solution ;
    /** returns 0 if no solution, 1 if valid solution.
        Fix variables if agree in useNumber_ solutions
        when_ 0 off, 1 only at new solutions, 2 also every now and then
        add 10 to make only if agree at lower bound
    */
    virtual int solution(double & objectiveValue,
                         double * newSolution);

    /// Sets number of solutions to use
    inline void setNumberSolutions(int value) {
        if (value > 0 && value <= 10)
            useNumber_ = value;
    }

protected:
    // Data
    /// Attempts
    std::vector <double> attempts_;
    /// Random numbers to stop same search happening
    double random_[10];
    /// Number of solutions so we only do after new solution
    int numberSolutions_;
    /// Number of solutions to use
    int useNumber_;
};

#endif