FractionTask/fraction.cpp

#include "fraction.hpp"

namespace FractionNS {

  int gcd(int p, int q) {
    while(true) {
        if(p == 0) return q;
        q %= p;
        if(q == 0) return p;
        p %= q;
      }
  }

  int lcm(int p, int q) {
    int gcd = FractionNS::gcd(p, q);

    return gcd != 0 ? (p / gcd * q) : 0;
  }

  int abs(int n)  {
    if(n < 0) return -n;
    return n;
  }


  Fraction::Fraction(int numerator, int denominator)
  {
    auto gcd = FractionNS::gcd(FractionNS::abs(numerator), FractionNS::abs(denominator));

    if(denominator < 0) {
        numerator *= -1;
        denominator *= -1;
      }

    this->m_numerator = numerator / gcd;
    this->m_denominator = denominator / gcd;
  }
  Fraction::Fraction(int n) {
    this->m_numerator = n;
    this->m_denominator = 1;
  }
  Fraction::Fraction(float n) {
    // TODO
    throw std::runtime_error("Not yet implemented");
  }
  Fraction::Fraction(const Fraction& n) {
    this->m_numerator = n.getNumerator();
    this->m_denominator = n.getDenominator();
  }

  int Fraction::getNumerator() const { return m_numerator; }
  int Fraction::getDenominator() const { return m_denominator; }

  void Fraction::setNumerator(int numerator) {
    auto gcd = std::__gcd(numerator, this->m_denominator);
    this->m_numerator = numerator / gcd;
  }
  void Fraction::setDenominator(int denominator) {
    auto gcd = std::__gcd(this->m_numerator, denominator);
    this->m_denominator = denominator / gcd;
  }

  QString Fraction::display() const {
    return QString::number(m_numerator) + '/' + QString::number(m_denominator);
  }

  bool Fraction::operator==(const int n) const {
    return (double(m_numerator) / double(m_denominator)) == n;
  }
  bool Fraction::operator==(const float n) const {
    return (double(m_numerator) / double(m_denominator)) == n;
  }
  bool Fraction::operator==(const double n) const {
    return (double(m_numerator) / double(m_denominator)) == n;
  }
  bool Fraction::operator==(const Fraction& n) const {
    return (this->m_numerator == n.getNumerator())
        && (this->m_denominator == n.getDenominator());
  }

  bool Fraction::operator!=(const int n) const {
    return (double(m_numerator) / double(m_denominator)) != n;
  }
  bool Fraction::operator!=(const float n) const {
    return (double(m_numerator) / double(m_denominator)) != n;
  }
  bool Fraction::operator!=(const double n) const {
    return (double(m_numerator) / double(m_denominator)) != n;
  }
  bool Fraction::operator!=(const Fraction& n) const {
    return (this->m_numerator != n.getNumerator())
        || (this->m_denominator != n.getDenominator());
  }

  Fraction& Fraction::operator+(const int n) const {
    return Fraction(n) + *this;
  }
  Fraction& Fraction::operator+(const float n) const {
    return Fraction(n) + *this;
  }
  Fraction& Fraction::operator+(const double n) const {
    return Fraction(n) + *this;
  }
  Fraction& Fraction::operator+(const Fraction& other) const {
    auto lcm = FractionNS::lcm(getDenominator(), other.getDenominator());
    return *new Fraction((getNumerator() + other.getNumerator()) * lcm, getDenominator() * lcm);
  }
}