//Rationals.cpp


#include"Rationals.h"



Rational::Rational()
{
  numerator=1;
  denominator=1;
}//end default constructor

//*******************

Rational::Rational(int n, int d)
{
  set(n,d);  //set does all the work, why repeat the code here?
}

//*******************

bool Rational::set(int n, int d)  //returns false if you try to set
                                  // denominator to 0
{
  numerator = n;
  if (d==0)
    {
    denominator = 1;
    cout << "\nBad denominator.\n";
    return false;
    } //end then clause
  //Only get here if denominator nonzero
  if (d<0)  //negative signs only in numerator
    {
    numerator=-numerator;
    denominator=-d;
    } 
  else //d>0
    denominator=d;  
  int factor=gcd(numerator,denominator);
  numerator=numerator/factor;
  denominator=denominator/factor;
  return true; 
}//end bool Rational::set(int n, int d)

//*******************                                  
        
int Rational::getNumerator() 
{
  return numerator;
} //end getNumerator()  

//*******************                                  

int Rational::getDenominator()
{
  return denominator;
} // end getDenominator

//*******************  

Rational Rational::operator+(Rational right)
{
  int n, d;
  n=numerator*right.denominator + 
      denominator*right.numerator;
  d=denominator*right.denominator;
  Rational answer(n,d);  
  return answer;
} // end operator+(Rational right)

//*******************

Rational Rational::operator-( Rational right)
{
  int n, d;
  n=numerator*right.denominator - 
      denominator*right.numerator;
  d=denominator*right.denominator;
  Rational answer(n,d);  
  return answer;
} // end  operator-(Rational right)                                
                                       
Rational Rational::operator*(Rational right)
{
  int n=numerator * right.numerator;
  int d=denominator * right.denominator;
  Rational answer(n,d);
  return answer;
}//end Rational::operator*(Rational right)

Rational Rational::operator/(Rational right)
{
  if (right.numerator==0)
    {
    cout << "\n**Division by Zero**\n";
    Rational answer=*this;
    return answer;
    }
  //not dividing by zero  
  int n=numerator * right.denominator;
  int d=denominator * right.numerator;
  Rational answer(n,d);
  return answer;
}//end Rational::operator/(Rational right)

//*******************

bool Rational::operator>(Rational right)
{
  return (numerator*right.denominator>denominator*right.numerator);
}//end Rational::operator>(Rational right)

//*******************

bool Rational::operator==(Rational right)
{
  return(numerator*right.denominator == denominator*right.numerator);
} //end Rational::operator==(Rational right)

//*******************
bool Rational::operator==(int right)
{
  return ( numerator == right * denominator );
}
//*******************

ostream& Rational::printquotient(ostream & outfile)
{
  outfile << numerator << '/' << denominator;
  return outfile;
}

//*******************

ostream& Rational::printdecimal(ostream & outfile)
{
  outfile << static_cast<float>(numerator)/denominator;
  return outfile;
} // end Rational::printdecimal(ostream & outfile)

//*******************

istream& Rational::read(istream & infile)
{
  int n,d;
  char c;
  infile >> n >> c >> d;
  set(n,d);
  return infile;
} // end  Rational::read(istream & infile)
//*******************


int Rational::gcd(int & n, int & d)
//given a and b, it will compute their GCD
//and divide them both by the GCD
{
  int q, r, b;
  int a=abs(n);
  b=d;
  q=a/b;  //integer division
  r=a-b*q;  //remaider
  int rold=b;
  while (r!=0)
    {
    a=b;
    b=r;
    q=a/b;
    rold=r;
    r=a-b*q;
    }//end while
  //rold is the gcd
  return rold;
}

//*******************

bool operator==(int left, Rational right)
{
  return(right==left);
}

//*******************


//#define RATIONAL_TEST
#ifdef RATIONAL_TEST

void testSetAndEuclid(Rational & r)
{
//test set and Euclid
  cout << "\nRelatively prime: ";  
  r.set(5,7);
  cout << "r is ";
  r.printquotient(cout);
  cout << "\nPositive, common factor: ";
  r.set(18,24);
  cout << "r is ";
  r.printquotient(cout);
  cout << "\nNegative numerator, common factor: ";
  r.set(-18,24);
  cout << "r is ";
  r.printquotient(cout);
  cout << "\nNegative denominator, common factor: ";
  r.set(18,-24);
  cout << "r is ";
  r.printquotient(cout);
  cout << "\nNegative both, common factor: ";
  r.set(-18,-24);
  cout << "r is ";
  r.printquotient(cout);
  cout << "\nZero denominator ";
  r.set(18,0);
  cout << "r is ";
  r.printquotient(cout);
}  //end testSetandEuclid

void testAlternateConstructor()
{
  Rational p(85,50);
  cout << "\nAlternate constructor, common factor: ";
  p.printquotient(cout);
  Rational p0(77,0);
  cout << "\nAlternate constructor, 0 denominator: ";
  p0.printquotient(cout);
}//end testAlternateConstructor

void testProdAndDivide()
{
  Rational a(4,6),b(5,-2),c(0,3);
  cout << "\nproducts and quotients\n";
  (a*b).printquotient(cout);
  cout << '\t';
  (a/b).printquotient(cout);
  cout << '\t';
  (c/b).printquotient(cout);
  cout << '\t';
  (b/c).printquotient(cout);
}

void testCompares()
{
Rational a(5,3), b(-4,6), c(2,-3), d(-4,2);
cout << "\nComparisons\n";
if (a>b)
  cout << "a greater than b";
if (b==c) 
  cout << "\nb and c are equal\n";
if (5 == a)
  cout << "a is an integer = 5\n";
else
  cout << " a is not an integer = 5\n";
if (-2 == d)
  cout << "d is and integer =-2\n";
if(d == -2)
  cout << "-2 = d\n";
if (a==c)
  cout << "\nTrouble.\n";
}

void testInputOutput()
{
    Rational r(2,3);
    Rational p;
    cout << "\nOutput\n";
    r.printdecimal(cout) << " is decimal and ";
    r.printquotient(cout) << " is a quotient.\n";
    cout << "Enter rational number r and p in the form #/# <enter> ";
    p.read(r.read(cin));
    cout << "\np is ";
    p.printquotient(cout);
    cout << "\tand r is ";
    r.printquotient(cout);
}

void testAddAndSubtract()
{
  Rational r(2,3), p(5,-2);
  cout << "\nSum and Difference\n";
  (r+p).printquotient(cout);
  cout << '\t' ;
  (r-p).printquotient(cout);
  cout << '\t';
  r=r-p;
  r.printquotient(cout);
} 

int main()
{
//setting up input and output files
  ofstream testout("rationalout.txt");
  ifstream testin("rationalin.txt");

//testing the default constructor
  Rational r,q;
  cout << "r is ";
  r.printquotient(cout);
  testout << "q is ";
  q.printquotient(testout);
  
//test set and Euclid
  testSetAndEuclid(r);

//test alternate constructor
  testAlternateConstructor();
  
//test operations
  testProdAndDivide();  
  testCompares();
  testAddAndSubtract();

  testInputOutput();
  
  
  return 0;
}
#endif