// a Rational object holds one Rational number, one fraction  // Carol Zander

#ifndef RAT2_H
#define RAT2_H
#include <iostream>
using namespace std;

//---------------------------------------------------------------------------
// Rational numbers:  defined as ratios of whole number, otherwise known as 
//    fractions (can be proper or improper), all follow the laws of arithmetic 
//    such as commutative law, associative law, distributive law, etc.
//    Examples include  2/3 , -7/8 , 20/9
//
// Assumptions:
//   -- Rationals are stored as integer numerators and denominators
//   -- if the rational number is negative, the numerator is the negative
//   -- all stored rationals are reduced to lowest terms
//   -- all arithmetic operators return Rationals reduced to lowest terms
//---------------------------------------------------------------------------

class Rational {

// overloaded <<: prints "DIVIDE BY ZERO ERROR!!!" if denominator is zero,
//    prints whole numbers without denominator (as ints), otherwise uses '/'
friend ostream& operator<<(ostream&, const Rational&);

// overloaded >>: takes 2 ints as numerator and denominator, does no
//    error checking, standard C casting between floats, char, etc occurs
friend istream& operator>>(istream&, Rational&);

public:
   // default constructor:  parameters are numerator and denominator resp.
   Rational(int = 0, int = 1 );                        

   // arithmetic operators
   Rational operator+(const Rational &) const;   // add 2 Rationals
   Rational operator-(const Rational &) const;   // subtract 2 Rationals
   Rational operator*(const Rational &) const;   // multiply 2 Rationals
   Rational operator/(const Rational &) const;   // divide 2 Rationals
                                                 // division by zero terminates 

   // boolean comparison operators
   bool operator>(const Rational &) const;       // is object > parameter?
   bool operator<(const Rational &) const;       // is object < parameter?
   bool operator>=(const Rational &) const;      // is object >= parameter?
   bool operator<=(const Rational &) const;      // is object >= parameter?
   bool operator==(const Rational &) const;      // is object == parameter?
   bool operator!=(const Rational &) const;      // is object != parameter?

   // assignment operators
   Rational& operator+=(const Rational &);       // current object += parameter
// Rational& operator-=(const Rational &);       // current object -= parameter
// Rational& operator*=(const Rational &);       // current object *= parameter
// Rational& operator/=(const Rational &);       // current object /= parameter
                                                 // division by zero terminates 

private:
   int numerator;                       // numerator of fraction
   int denominator;                     // denominator of fraction
   void reduce();                       // reduce fraction to lowest terms
};

#endif