CglTreeInfo.hpp

// $Id$
// Copyright (C) 2000, International Business Machines
// Corporation and others.  All Rights Reserved.
// This code is licensed under the terms of the Eclipse Public License (EPL).

#ifndef CglTreeInfo_H
#define CglTreeInfo_H

#include "OsiCuts.hpp"
#include "OsiSolverInterface.hpp"
#include "CoinHelperFunctions.hpp"
class CglStored;
/** Information about where the cut generator is invoked from. */

class CglTreeInfo {
public:
  /// The level of the search tree node
  int level;
  /** How many times the cut generator was already invoked in this search tree
      node */
  int pass;
  /** The number of rows in the original formulation. Some generators may not
      want to consider already generated rows when generating new ones. */
  int formulation_rows;
  /** Options 
      1 - treat costed integers as important
      2 - switch off some stuff as variables semi-integer
      4 - set global cut flag if at root node
      8 - set global cut flag if at root node and first pass
      16 - set global cut flag and make cuts globally valid
      32 - last round of cuts did nothing - maybe be more aggressive
      64 - in preprocessing stage
      128 - looks like solution
      256 - want alternate cuts
      512 - in sub tree (i.e. parent model)
      1024 - in must call again mode or after everything mode
  */
  int options;
  /// Set true if in tree (to avoid ambiguity at first branch)
  bool inTree;
  /** nonzero if called from child of main model
      1 if heuristic run
      2 if doing full search
  */
  int hasParent;
  /// parent solver
  OsiSolverInterface *parentSolver;
  /// Original columns (if preprocessed)
  int *originalColumns;
  /** Replacement array.  Before Branch and Cut it may be beneficial to strengthen rows
      rather than adding cuts.  If this array is not NULL then the cut generator can
      place a pointer to the stronger cut in this array which is number of rows in size.

      A null (i.e. zero elements and free rhs) cut indicates that the row is useless 
      and can be removed.

      The calling function can then replace those rows.
  */
  OsiRowCut **strengthenRow;
  /// Optional pointer to thread specific random number generator
  CoinThreadRandom *randomNumberGenerator;
  /// Default constructor
  CglTreeInfo();

  /// Copy constructor
  CglTreeInfo(
    const CglTreeInfo &);
  /// Clone
  virtual CglTreeInfo *clone() const;

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

  /// Destructor
  virtual ~CglTreeInfo();
  /// Take action if cut generator can fix a variable (toValue -1 for down, +1 for up)
  virtual bool fixes(int, int, int, bool) { return false; }
  /** Initalizes fixing arrays etc - returns >0 if we want to save info
      0 if we don't and -1 if is to be used */
  virtual int initializeFixing(const OsiSolverInterface *) { return 0; }
};

/** Derived class to pick up probing info. */
typedef struct {
  //unsigned int oneFixed:1; //  nonzero if variable to 1 fixes all
  //unsigned int sequence:31; //  variable (in matrix) (but also see cliqueRow_)
  unsigned int fixes;
} CliqueEntry;

class CglTreeProbingInfo : public CglTreeInfo {
public:
  /// Default constructor
  CglTreeProbingInfo();
  /// Constructor from model
  CglTreeProbingInfo(const OsiSolverInterface *model);

  /// Copy constructor
  CglTreeProbingInfo(
    const CglTreeProbingInfo &);
  /// Clone
  virtual CglTreeInfo *clone() const;

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

  /// Destructor
  virtual ~CglTreeProbingInfo();
  OsiSolverInterface *analyze(const OsiSolverInterface &si, int createSolver = 0,
    int numberExtraCliques = 0, const CoinBigIndex *starts = NULL,
    const CliqueEntry *entries = NULL, const char *type = NULL);
  /** Take action if cut generator can fix a variable 
      (toValue -1 for down, +1 for up)
      Returns true if still room, false if not  */
  virtual bool fixes(int variable, int toValue, int fixedVariable, bool fixedToLower);
  /** Initalizes fixing arrays etc - returns >0 if we want to save info
      0 if we don't and -1 if is to be used */
  virtual int initializeFixing(const OsiSolverInterface *model);
  /// Fix entries in a solver using implications
  int fixColumns(OsiSolverInterface &si) const;
  /// Fix entries in a solver using implications for one variable
  int fixColumns(int iColumn, int value, OsiSolverInterface &si) const;
  /// Packs down entries
  int packDown();
  /// Generate cuts from implications
  void generateCuts(const OsiSolverInterface &si, OsiCuts &cs,
    const CglTreeInfo info) const;
  /// Entries for fixing variables
  inline CliqueEntry *fixEntries()
  {
    convert();
    return fixEntry_;
  }
  /// Starts of integer variable going to zero
  inline int *toZero()
  {
    convert();
    return toZero_;
  }
  /// Starts of integer variable going to one
  inline int *toOne()
  {
    convert();
    return toOne_;
  }
  /// List of 0-1 integer variables
  inline int *integerVariable() const
  {
    return integerVariable_;
  }
  /// Backward look up
  inline int *backward() const
  {
    return backward_;
  }
  /// Number of variables
  inline int numberVariables() const
  {
    return numberVariables_;
  }
  /// Number of 0-1 variables
  inline int numberIntegers() const
  {
    return numberIntegers_;
  }

private:
  /// Converts to ordered
  void convert();

protected:
  /// Entries for fixing variables
  CliqueEntry *fixEntry_;
  /// Starts of integer variable going to zero
  int *toZero_;
  /// Starts of integer variable going to one
  int *toOne_;
  /// List of 0-1 integer variables
  int *integerVariable_;
  /// Backward look up
  int *backward_;
  /// Entries for fixing variable when collecting
  int *fixingEntry_;
  /// Number of variables
  int numberVariables_;
  /// Number of 0-1 variables
  int numberIntegers_;
  /// Maximum number in fixEntry_
  int maximumEntries_;
  /// Number entries in fixingEntry_ (and fixEntry_) or -2 if correct style
  int numberEntries_;
};
inline int sequenceInCliqueEntry(const CliqueEntry &cEntry)
{
  return cEntry.fixes & 0x7fffffff;
}
inline void setSequenceInCliqueEntry(CliqueEntry &cEntry, int sequence)
{
  cEntry.fixes = sequence | (cEntry.fixes & 0x80000000);
}
inline bool oneFixesInCliqueEntry(const CliqueEntry &cEntry)
{
  return (cEntry.fixes & 0x80000000) != 0;
}
inline void setOneFixesInCliqueEntry(CliqueEntry &cEntry, bool oneFixes)
{
  cEntry.fixes = (oneFixes ? 0x80000000 : 0) | (cEntry.fixes & 0x7fffffff);
}

#endif

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