hw_rational_numbers

#include<iostream>
#include <vector>

class RationalNumber
{
public: // Constructors
  RationalNumber(int numerator)
  {
    numerator_ = numerator;
    denominator_ = 1;
  }

  RationalNumber(int numerator, int denominator)
  {
    if (denominator == 0)
      throw std::logic_error("Denominator could not be zero!");

    numerator_ = numerator;
    denominator_ = denominator;

    simplify_current_fraction();
  }

public:
  RationalNumber& operator+=(const RationalNumber& right)
  {
    const int new_numerator = numerator_ * right.denominator_ + right.numerator_ * denominator_;
    const int new_denominator = denominator_ * right.denominator_;

    numerator_ = new_numerator;
    denominator_ = new_denominator;

    simplify_current_fraction();

    return *this;
  }

  RationalNumber operator+(const RationalNumber& right) const
  {
    RationalNumber result(*this);
    result += right;

    return result;
  }

  RationalNumber& operator-=(const RationalNumber& right)
  {
    const int new_numerator = numerator_ * right.denominator_ - right.numerator_ * denominator_;
    const int new_denominator = denominator_ * right.denominator_;

    numerator_ = new_numerator;
    denominator_ = new_denominator;

    simplify_current_fraction();

    return *this;
  }

  RationalNumber operator-(const RationalNumber& right) const
  {
    RationalNumber result(*this);
    result -= right;

    return result;
  }

  RationalNumber& operator*=(const RationalNumber& right)
  {
    numerator_ *= right.numerator_;
    denominator_ *= right.denominator_;

    simplify_current_fraction();

    return *this;
  }

  RationalNumber operator*(const RationalNumber& right) const
  {
    RationalNumber result(*this);
    result *= right;

    return result;
  }

  RationalNumber& operator/=(const RationalNumber& right)
  {
    numerator_ *= right.denominator_;
    denominator_ *= right.numerator_;

    simplify_current_fraction();

    return *this;
  }

  RationalNumber operator/(const RationalNumber& right) const
  {
    RationalNumber result(*this);
    result /= right;

    return result;
  }

  RationalNumber operator-() const
  {
    return RationalNumber(-numerator_, denominator_);
  }

public: // Overload operator =
  RationalNumber& operator=(const RationalNumber& right)
  {
    if(this != &right)
    {
      numerator_ = right.numerator_;
      denominator_ = right.denominator_;
    }

    return *this;
  }

public: // Overload boolean operators
  bool operator==(const RationalNumber& right) const
  {
    return numerator_ == right.numerator_ && denominator_ == right.denominator_;
  }

  bool operator<(const RationalNumber& right) const
  {
    return numerator_ * right.denominator_ < right.numerator_* denominator_;
  }

  bool operator<=(const RationalNumber& right) const
  {
    return *this < right || *this == right;
  }

  bool operator>(const RationalNumber& right) const
  {
    return !(*this <= right);
  }

  bool operator>=(const RationalNumber& right) const
  {
    return !(*this < right);
  }

public:
  friend std::ostream& operator<<(std::ostream& os, const RationalNumber& rational_number);

private:
  void simplify_current_fraction()
  {
    const int count = std::max(numerator_, denominator_);

    // Here we try to simplify the fraction: if both - numerator & denominator could be divided on value - they will be ;)
    // Example: On input: 12 / 24 = 2 * 2 * 3 / 2 * 2 * 2 * 3 = 1 / 3 will be output
    for(int possible_divider = 2; possible_divider < count; ++possible_divider)
    {
      while (numerator_ % possible_divider == 0 && denominator_ % possible_divider == 0)
      {
        numerator_ /= possible_divider;
        denominator_ /= possible_divider;
      }
    }
  }

private:
  int denominator_;
  int numerator_;
};

std::ostream& operator<<(std::ostream& os, const RationalNumber& rational_number)
{
  os << rational_number.numerator_ << "/" << rational_number.denominator_;
  return os;
}


int main()
{
  const RationalNumber first(12, 24);
  const RationalNumber second(2, 3);

  std::cout << "fist = " << first << " " << " second = " << second << std::endl;

  std::cout << first + second << std::endl;
  std::cout << first - second << std::endl;
  std::cout << first * second << std::endl;
  std::cout << first / second << std::endl;

  RationalNumber result = first + second;

  return 0;
}