Лабораторные работы С++ (для ИВТ) / Готовые лабы С++ / Лаба4 / Laba 4 (4)

#include <iostream>
#include <locale>
#include <cmath>
using namespace std;

class rational {
    int numerator;
    int denominator;
    
    void reduce() {
        int gcd_val = gcd(abs(numerator), abs(denominator));
        numerator /= gcd_val;
        denominator /= gcd_val;
        if (denominator < 0) {
            numerator = -numerator;
            denominator = -denominator;
        }
    }
    
    int gcd(int a, int b) const {
        while (b != 0) {
            int temp = b;
            b = a % b;
            a = temp;
        }
        return a;
    }
    
public:
    // Конструктор (может использоваться как конструктор преобразования)
    rational(int num = 0, int den = 1) : numerator(num), denominator(den) {
        if (denominator == 0) denominator = 1;
        reduce();
    }
    
    // Арифметические операции
    rational operator+(const rational& other) const {
        return rational(numerator * other.denominator + other.numerator * denominator,
                       denominator * other.denominator);
    }
    
    rational operator-(const rational& other) const {
        return rational(numerator * other.denominator - other.numerator * denominator,
                       denominator * other.denominator);
    }
    
    rational operator*(const rational& other) const {
        return rational(numerator * other.numerator,
                       denominator * other.denominator);
    }
    
    rational operator/(const rational& other) const {
        return rational(numerator * other.denominator,
                       denominator * other.numerator);
    }
    
    // Операции с целыми числами
    friend rational operator+(const rational& r, int n);
    friend rational operator+(int n, const rational& r);
    
    // Операции сравнения
    bool operator==(const rational& other) const {
        return numerator == other.numerator && denominator == other.denominator;
    }
    
    bool operator<(const rational& other) const {
        return numerator * other.denominator < other.numerator * denominator;
    }
    
    // Приведение к double
    operator double() const {
        return static_cast<double>(numerator) / denominator;
    }
    
    void print() const {
        cout << numerator << "/" << denominator;
    }
};

rational operator+(const rational& r, int n) {
    return r + rational(n);
}

rational operator+(int n, const rational& r) {
    return rational(n) + r;
}

int main() {
    setlocale(LC_ALL, "ru_RU.UTF-8");
    
    rational r1(2, 3);
    rational r2(1, 4);
    
    cout << "r1 = "; r1.print(); cout << endl;
    cout << "r2 = "; r2.print(); cout << endl;
    
    rational sum = r1 + r2;
    cout << "Сумма: "; sum.print(); cout << endl;
    
    rational prod = r1 * r2;
    cout << "Произведение: "; prod.print(); cout << endl;
    
    cout << "r1 как double: " << static_cast<double>(r1) << endl;
    
    // Конструктор преобразования
    rational r3 = 5; // int -> rational
    cout << "r3 = "; r3.print(); cout << endl;
    
    return 0;
}