// rational.cc
// member function definitions for rational class
// for Problem 6.6 in D&D

#include "rational.h"
#include <iostream.h>
#include <iomanip.h>
#include <math.h>

// constructor function to initialize private data
// default to 0 (see class definition)
rational::rational(int num, int denom)
{
  setrational(num, denom);
}

// set the numerator and denominator
void rational::setrational(int num, int denom)
{
  numerator = num;
  denominator = (denom == 0) ? 1 : denom;
}

// get functions
int rational::getnumerator()
{
  return numerator;
}


int rational::getdenominator()
{
  return denominator;
}
  
// printing functions
void rational::printfract()
{
  cout << numerator << "/" << denominator << endl;
}

void rational::printfloat()
{
  cout << setiosflags(ios::fixed | ios::showpoint) 
    << setprecision(2)  <<  ((float) numerator / denominator) << endl;
}
  
// arithmetic functions
rational rational::add(rational r2)
{
  // use two temps because this and r2 will be altered in processing
  rational temp1, temp2;
  temp1 = (*this);
  temp2 = r2;
  rational solution;
  makeCommonDenom(r2);
  solution.setrational((numerator + r2.numerator),
		       denominator);
  solution.reduceform();
  // reset this and r2 to original form
  (*this) = temp1;
  r2 = temp2;
  return solution;
}

rational rational::subtract(rational r2)
{
  // use two temps because this and r2 will be altered in processing
  rational temp1, temp2;
  temp1 = (*this);
  temp2 = r2;
  rational solution;
  makeCommonDenom(r2);
  solution.setrational((numerator - r2.numerator),
		       denominator);
  solution.reduceform();
  // reset this and r2 to original form
  (*this) = temp1;
  r2 = temp2;
  return solution;
}

rational rational::mult(rational r2)
{
  rational solution;
  solution.setrational((numerator * r2.numerator),
		       (denominator * r2.denominator));
  solution.reduceform();
  return solution;
}

rational rational::divide(rational r2)
{
  rational solution;
  solution.setrational((numerator * r2.denominator),
		       (denominator * r2.numerator));
  solution.reduceform();
  return solution;
}

int rational::findCommonDenom(rational r2)
{
  return (denominator * r2.denominator);
}

// reduces the form of the rational number
void rational::reduceform()
{
  int num, denom, i, smaller;

  //  cout << "Entering  reduceform with numberator = " << numerator 
  //       << " and denominator = " << denominator << endl;

  num = numerator;
  denom = denominator;
  smaller = 
    (fabs(static_cast<double>(numerator)) 
     <= fabs(static_cast<double>(denominator))) 
    ? 
    fabs(static_cast<double>(numerator)) 
    : 
    fabs(static_cast<double>(denominator));
  i = 2;

  while (i <= smaller)
    {
      //      cout << endl << "in reduceform -- i = " << i << ", smaller = "
      //   << smaller
      //   << ", num = " << num << ", denom = " << denom << endl;

      if ((num % i) == 0 && (denom % i) == 0)
	{
	  num /= i;
	  denom /= i;
	  smaller /= i;
	}
      else i++;
    }
    numerator = num;
    denominator = denom;
}

// alters the rational numbers this and r2 so that they 
// have a common denominator
void rational::makeCommonDenom(rational &r2)
{
  int cdenom;
  cdenom = findCommonDenom(r2);

  numerator *= (cdenom / denominator);
  denominator = cdenom;

  r2.numerator *= (cdenom / r2.denominator);
  r2.denominator = cdenom;       
					
}