rational.h

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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*                                                                           */
/*                  This file is part of the class library                   */
/*       SoPlex --- the Sequential object-oriented simPlex.                  */
/*                                                                           */
/*    Copyright (C) 1996-2019 Konrad-Zuse-Zentrum                            */
/*                            fuer Informationstechnik Berlin                */
/*                                                                           */
/*  SoPlex is distributed under the terms of the ZIB Academic Licence.       */
/*                                                                           */
/*  You should have received a copy of the ZIB Academic License              */
/*  along with SoPlex; see the file COPYING. If not email to soplex@zib.de.  */
/*                                                                           */
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/**@file  rational.h
 * @brief Wrapper for GMP types.
 */
#ifndef _RATIONAL_H_
#define _RATIONAL_H_

#include <math.h>
#include <assert.h>
#include <string.h>
#include <iostream>

#include "soplex/spxdefines.h"
#include "soplex/idlist.h"

#ifdef SOPLEX_WITH_GMP
#include "gmp.h"
#endif


namespace soplex
{
/**@brief   Wrapper for GMP type mpq_class.
 * @ingroup Algebra
 *
 * We wrap mpq_class so that we can replace it by a double type if GMP is not available.
 */

/// If compiled with GMP support, Rational is defined as mpq_class.
class Rational
{
private:
   class Private;
   Private* dpointer;

#ifdef SOPLEX_WITH_GMP
   THREADLOCAL static IdList< Private > unusedPrivateList;
   THREADLOCAL static bool useListMem;


   /// special constructor only for initializing static rational variables; this is necessary since we need a
   /// constructor for Rational::{ZERO, POSONE, NEGONE} that does not use these numbers
   Rational(const int& i, const bool& dummy);

   //**@name Static variables for special rational values */
   //@{

   static const Rational ZERO;
   static const Rational POSONE;
   static const Rational NEGONE;

   //@}
#endif

public:

   //**@name Construction and destruction */
   //@{

   /// default constructor
   Rational();

   /// copy constructor
   Rational(const Rational& r);

   /// constructor from long double
   Rational(const long double& r);

   /// constructor from double
   Rational(const double& r);

   ///constructor from int
   Rational(const int& i);

#ifdef SOPLEX_WITH_GMP
   /// constructor from mpq_t
   Rational(const mpq_t& q);
#endif

   /// destructor
   ~Rational();

   /// enables list memory
   static void enableListMem();

   /// frees the unused rational elements in the memory list
   /** this can be useful when you want to save memory or needed when working with a GMP memory manager like the one
    *  in EGlib that frees GMP memory before the destructor of the static memory list is called; in most cases this
    *  method is optional; note that this does not free the Rational elements that are currently in use
    */
   static void freeListMem();

   /// disables list memory
   static void disableListMem();

   /// assignment operator
   Rational& operator=(const Rational&);

   /// assignment operator from long double
   Rational& operator=(const long double& r);

   /// assignment operator from double
   Rational& operator=(const double& r);

   /// assignment operator from int
   Rational& operator=(const int& i);

#ifdef SOPLEX_WITH_GMP
   /// assignment operator from mpq_t
   Rational& operator=(const mpq_t& q);
#endif

   //@}


   //**@name Typecasts */
   //@{

   operator double() const;
   operator long double() const;

#ifdef SOPLEX_WITH_GMP
   /// provides read-only access to underlying mpq_t
   const mpq_t* getMpqPtr() const;

   /// provides read-only access to underlying mpq_t
   const mpq_t& getMpqRef() const;

   /// provides write access to underlying mpq_t; use with care
   mpq_t* getMpqPtr_w() const;

   /// provides write access to underlying mpq_t; use with care
   mpq_t& getMpqRef_w() const;
#endif
   //@}


   //**@name Arithmetic operators */
   //@{

   /// addition operator
   Rational operator+(const Rational& r) const;

   /// addition assignment operator
   Rational& operator+=(const Rational& r);

   /// addition operator for doubles
   Rational operator+(const double& r) const;

   /// addition assignment operator  for doubles
   Rational& operator+=(const double& r);

   /// addition operator for ints
   Rational operator+(const int& r) const;

   /// addition assignment operator  for ints
   Rational& operator+=(const int& r);

   /// subtraction operator
   Rational operator-(const Rational& r) const;

   /// subtraction assignment operator
   Rational& operator-=(const Rational& r);

   /// subtraction operator for doubles
   Rational operator-(const double& r) const;

   /// subtraction assignment operator for doubles
   Rational& operator-=(const double& r);

   /// subtraction operator for ints
   Rational operator-(const int& r) const;

   /// subtraction assignment operator for ints
   Rational& operator-=(const int& r);

   /// multiplication operator
   Rational operator*(const Rational& r) const;

   /// multiplication assignment operator operator
   Rational& operator*=(const Rational& r);

   /// multiplication operator for doubles
   Rational operator*(const double& r) const;

   /// multiplication assignment operator for doubles
   Rational& operator*=(const double& r);

   /// multiplication operator for ints
   Rational operator*(const int& r) const;

   /// multiplication assignment operator for ints
   Rational& operator*=(const int& r);

   /// division operator
   Rational operator/(const Rational& r) const;

   /// division assignment operator
   Rational& operator/=(const Rational& r);

   /// division operator for doubles
   Rational operator/(const double& r) const;

   /// division assignment operator for doubles
   Rational& operator/=(const double& r);

   /// division operator for ints
   Rational operator/(const int& r) const;

   /// division assignment operator for ints
   Rational& operator/=(const int& r);

   /// add product of two rationals
   Rational& addProduct(const Rational& r, const Rational& s);

   /// subtract product of two rationals
   Rational& subProduct(const Rational& r, const Rational& s);

   /// add quotient of two rationals, r divided by s
   Rational& addQuotient(const Rational& r, const Rational& s);

   /// subtract quotient of two rationals, r divided by s
   Rational& subQuotient(const Rational& r, const Rational& s);

   /// inversion
   Rational& invert();

   /// round up to next power of two
   Rational& powRound();

   //@}


   //**@name Methods for checking exactness of doubles  */
   //@{

   /// checks if \p d is the closest number that can be represented by double
   bool isNextTo(const double& d);

   /// checks if \p d is exactly equal to the Rational and if not, if it is one of the two adjacent doubles
   bool isAdjacentTo(const double& d) const;

   //@}


   //**@name Methods for querying size */
   //@{

   /// Size in specified base (bit size for base 2)
   int sizeInBase(const int base = 2) const;

   //@}


   //**@name Static methods  */
   //@{

   /// returns precision of Rational implementation, i.e., number of bits used to store Rational numbers (INT_MAX if exact)
   static int precision();

   //@}


   //**@name Conversion from and to String */
   //@{

   /// read Rational from string
   bool readString(const char* s);

   friend std::string rationalToString(const Rational& r, const int precision);
   friend bool readStringRational(const char* s, Rational& value);
   friend std::ostream& operator<<(std::ostream& os, const Rational& q);

   //@}


   //**@name Friends */
   //@{

   friend int compareRational(const Rational& r, const Rational& s);
   friend bool operator!=(const Rational& r, const Rational& s);
   friend bool operator==(const Rational& r, const Rational& s);
   friend bool operator<(const Rational& r, const Rational& s);
   friend bool operator<=(const Rational& r, const Rational& s);
   friend bool operator>(const Rational& r, const Rational& s);
   friend bool operator>=(const Rational& r, const Rational& s);

   friend bool operator!=(const Rational& r, const double& s);
   friend bool operator==(const Rational& r, const double& s);
   friend bool operator<(const Rational& r, const double& s);
   friend bool operator<=(const Rational& r, const double& s);
   friend bool operator>(const Rational& r, const double& s);
   friend bool operator>=(const Rational& r, const double& s);

   friend bool operator!=(const double& r, const Rational& s);
   friend bool operator==(const double& r, const Rational& s);
   friend bool operator<(const double& r, const Rational& s);
   friend bool operator<=(const double& r, const Rational& s);
   friend bool operator>(const double& r, const Rational& s);
   friend bool operator>=(const double& r, const Rational& s);

   friend bool operator!=(const Rational& r, const long double& s);
   friend bool operator==(const Rational& r, const long double& s);
   friend bool operator<(const Rational& r, const long double& s);
   friend bool operator<=(const Rational& r, const long double& s);
   friend bool operator>(const Rational& r, const long double& s);
   friend bool operator>=(const Rational& r, const long double& s);

   friend bool operator!=(const long double& r, const Rational& s);
   friend bool operator==(const long double& r, const Rational& s);
   friend bool operator<(const long double& r, const Rational& s);
   friend bool operator<=(const long double& r, const Rational& s);
   friend bool operator>(const long double& r, const Rational& s);
   friend bool operator>=(const long double& r, const Rational& s);

   friend Rational operator+(const double& d, const Rational& r);
   friend Rational operator-(const double& d, const Rational& r);
   friend Rational operator*(const double& d, const Rational& r);
   friend Rational operator/(const double& d, const Rational& r);

   friend bool operator!=(const Rational& r, const int& s);
   friend bool operator==(const Rational& r, const int& s);
   friend bool operator<(const Rational& r, const int& s);
   friend bool operator<=(const Rational& r, const int& s);
   friend bool operator>(const Rational& r, const int& s);
   friend bool operator>=(const Rational& r, const int& s);

   friend bool operator!=(const int& r, const Rational& s);
   friend bool operator==(const int& r, const Rational& s);
   friend bool operator<(const int& r, const Rational& s);
   friend bool operator<=(const int& r, const Rational& s);
   friend bool operator>(const int& r, const Rational& s);
   friend bool operator>=(const int& r, const Rational& s);

   friend Rational operator+(const int& d, const Rational& r);
   friend Rational operator-(const int& d, const Rational& r);
   friend Rational operator*(const int& d, const Rational& r);
   friend Rational operator/(const int& d, const Rational& r);

   friend Rational spxAbs(const Rational& r);
   friend int sign(const Rational& r);
   friend Rational operator-(const Rational& q);

   //@}
};


//**@name Parsing and printing */
//@{

/// convert rational number to string
std::string rationalToString(const Rational& r, const int precision = 32);

/// read Rational from string
bool readStringRational(const char* s, Rational& value);

/// print Rational
std::ostream& operator<<(std::ostream& os, const Rational& r);

//@}


//**@name Relational operators */
//@{

/// comparison operator returning a positive value if r > s, zero if r = s, and a negative value if r < s
int compareRational(const Rational& r, const Rational& s);

/// equality operator
bool operator==(const Rational& r, const Rational& s);

/// inequality operator
bool operator!=(const Rational& r, const Rational& s);

/// less than operator
bool operator<(const Rational& r, const Rational& s);

/// less than or equal to operator
bool operator<=(const Rational& r, const Rational& s);

/// greater than operator
bool operator>(const Rational& r, const Rational& s);

/// greater than or equal to operator
bool operator>=(const Rational& r, const Rational& s);

/// equality operator for Rational and double
bool operator==(const Rational& r, const double& s);

/// inequality operator for Rational and double
bool operator!=(const Rational& r, const double& s);

/// less than operator for Rational and double
bool operator<(const Rational& r, const double& s);

/// less than or equal to operator for Rational and double
bool operator<=(const Rational& r, const double& s);

/// greater than operator for Rational and double
bool operator>(const Rational& r, const double& s);

/// greater than or equal to operator for Rational and double
bool operator>=(const Rational& r, const double& s);

/// equality operator for double and Rational
bool operator==(const double& r, const Rational& s);

/// inequality operator for double and Rational
bool operator!=(const double& r, const Rational& s);

/// less than operator for double and Rational
bool operator<(const double& r, const Rational& s);

/// less than or equal to operator for double and Rational
bool operator<=(const double& r, const Rational& s);

/// greater than operator for double and Rational
bool operator>(const double& r, const Rational& s);

/// greater than or equal to operator for double and Rational
bool operator>=(const double& r, const Rational& s);

/// equality operator for Rational and long double
bool operator==(const Rational& r, const long double& s);

/// inequality operator for Rational and long double
bool operator!=(const Rational& r, const long double& s);

/// less than operator for Rational and long double
bool operator<(const Rational& r, const long double& s);

/// less than or equal to operator for Rational and long double
bool operator<=(const Rational& r, const long double& s);

/// greater than operator for Rational and long double
bool operator>(const Rational& r, const long double& s);

/// greater than or equal to operator for Rational and long double
bool operator>=(const Rational& r, const long double& s);

/// equality operator for long double and Rational
bool operator==(const long double& r, const Rational& s);

/// inequality operator for long double and Rational
bool operator!=(const long double& r, const Rational& s);

/// less than operator for long double and Rational
bool operator<(const long double& r, const Rational& s);

/// less than or equal to operator for long double and Rational
bool operator<=(const long double& r, const Rational& s);

/// greater than operator for long double and Rational
bool operator>(const long double& r, const Rational& s);

/// greater than or equal to operator for long double and Rational
bool operator>=(const long double& r, const Rational& s);

/// equality operator for Rational and int
bool operator==(const Rational& r, const int& s);

/// inequality operator for Rational and int
bool operator!=(const Rational& r, const int& s);

/// less than operator for Rational and int
bool operator<(const Rational& r, const int& s);

/// less than or equal to operator for Rational and int
bool operator<=(const Rational& r, const int& s);

/// greater than operator for Rational and int
bool operator>(const Rational& r, const int& s);

/// greater than or equal to operator for Rational and int
bool operator>=(const Rational& r, const int& s);

/// equality operator for int and Rational
bool operator==(const int& r, const Rational& s);

/// inequality operator for int and Rational
bool operator!=(const int& r, const Rational& s);

/// less than operator for int and Rational
bool operator<(const int& r, const Rational& s);

/// less than or equal to operator for int and Rational
bool operator<=(const int& r, const Rational& s);

/// greater than operator for int and Rational
bool operator>(const int& r, const Rational& s);

/// greater than or equal to operator for int and Rational
bool operator>=(const int& r, const Rational& s);

//@}


//**@name Non-member arithmetic operators and functions */
//@{

/// addition operator for double and Rational
Rational operator+(const double& d, const Rational& r);

/// addition operator for double and Rational
Rational operator+(const double& d, const Rational& r);

/// addition operator for double and Rational
Rational operator+(const double& d, const Rational& r);

/// addition operator for double and Rational
Rational operator+(const double& d, const Rational& r);

/// addition operator for int and Rational
Rational operator+(const int& d, const Rational& r);

/// addition operator for int and Rational
Rational operator+(const int& d, const Rational& r);

/// addition operator for int and Rational
Rational operator+(const int& d, const Rational& r);

/// addition operator for int and Rational
Rational operator+(const int& d, const Rational& r);

/// absolute function
Rational spxAbs(const Rational& r);

/// Sign function; returns 1 if r > 0, 0 if r = 0, and -1 if r < 0.
int sign(const Rational& r);

/// Negation.
Rational operator-(const Rational& r);

/// Total size of rational vector.
int totalSizeRational(const Rational* vector, const int length, const int base = 2);

/// Size of least common multiple of denominators in rational vector.
int dlcmSizeRational(const Rational* vector, const int length, const int base = 2);

/// Size of largest denominator in rational vector.
int dmaxSizeRational(const Rational* vector, const int length, const int base = 2);

//@}

} // namespace soplex

#endif // _RATIONAL_H_