2.2j.cpp

#include <iostream>
#include <locale>

using namespace std;

class Fraction {
public:
    // Конструктор
    Fraction() {
        num = 0;
        denom = 1;
    }

    Fraction(int n, int d) {
        num = n;
        denom = (d == 0 ? 1 : d);
        reduce();
    }

    // Операторы
    Fraction add(Fraction b) {
        Fraction res;
        res.num = num * b.denom + b.num * denom;
        res.denom = denom * b.denom;
        res.reduce();
        return res;
    }

    Fraction sub(Fraction b) {
        Fraction res;
        res.num = num * b.denom - b.num * denom;
        res.denom = denom * b.denom;
        res.reduce();
        return res;
    }

    Fraction mul(Fraction b) {
        Fraction res;
        res.num = num * b.num;
        res.denom = denom * b.denom;
        res.reduce();
        return res;
    }

    Fraction div(Fraction b) {
        Fraction res;
        if (b.num == 0) {
            res.num = 0; res.denom = 1;
        }
        else {
            res.num = num * b.denom;
            res.denom = denom * b.num;
            res.reduce();
        }
        return res;
    }

    // Сокращение дроби
    void reduce() {
        int a = abs(num), b = abs(denom);
        int r;
        while (b != 0) {
            r = a % b;
            a = b;
            b = r;
        }
        if (a != 0) {
            num /= a;
            denom /= a;
        }
        if (denom < 0) {
            num = -num;
            denom = -denom;
        }
    }

    // Вывод
    void print() {
        cout << num;
        if (denom != 1)
            cout << "/" << denom;
    }

    // Статический gcd
    static int gcd(int a, int b) {
        int r;
        while (b != 0) {
            r = a % b;
            a = b;
            b = r;
        }
        return a;
    }

    // Статический метод: перевод десятичных в простую дробь (грубый)
    static void printAsFraction(double d) {
        int den = 10000;
        int num = int(d * den + 0.5);
        int g = gcd(num, den);
        num /= g;
        den /= g;
        cout << num << "/" << den << endl;
    }

    int num, denom;
};


int main() {
    setlocale(LC_ALL, "Russian");

    cout << " ЛАБОРАТОРНАЯ №2, ЗАДАНИЕ 2: Класс Fraction\n";
    Fraction a(1, 2), b(1, 3), c(3, 4), d(2, 5);

    cout << "\nИсходные дроби:\n";
    cout << "a = "; a.print(); cout << endl;
    cout << "b = "; b.print(); cout << endl;
    cout << "c = "; c.print(); cout << endl;
    cout << "d = "; d.print(); cout << endl;

    cout << "\nСложение: "; a.print(); cout << " + "; b.print(); cout << " = ";
    Fraction sum = a.add(b); sum.print(); cout << endl;

    cout << "Вычитание: "; c.print(); cout << " - "; d.print(); cout << " = ";
    Fraction sub = c.sub(d); sub.print(); cout << endl;

    cout << "Умножение: "; a.print(); cout << " * "; c.print(); cout << " = ";
    Fraction mul = a.mul(c); mul.print(); cout << endl;

    cout << "Деление: "; b.print(); cout << " / "; d.print(); cout << " = ";
    Fraction div = b.div(d); div.print(); cout << endl;

    cout << "\nСокращение дроби 15/45: ";
    Fraction f(15, 45); f.print(); cout << endl;

    cout << "\nПеревод из десятичной:\n";
    cout << "0.25 = "; Fraction::printAsFraction(0.25);
    cout << "0.333 = "; Fraction::printAsFraction(0.333);
    cout << "1.125 = "; Fraction::printAsFraction(1.125);

    cout << "\n ПРОГРАММА ЗАВЕРШЕНА \n";
    return 0;
}