Rational numbers (1) P85696

Using the definition

    struct Rational {
        int num, den;
    };

write a function

    Rational rational(int n, int d);

that returns an equivalent rational to $\frac{n}{d}$ and “normalized” according to: if the numerator is 0, the denominator is 1; otherwise, the numerator and the denominator do not have any common factor, and the denominator is positive.

Precondition

@d@ $\neq 0$.

Observation

You only need to submit the required classes; your main program will be ignored.

Strictly obey the type definitions of the statement.