const Rational Rational::operator-(const Rational &r) const {
// Do division first to reduce chance of integer overflow errors.
int lcm, pnew;
lcm = r.GetQ()/gcd(this->den, r.GetQ());
lcm *= this->den;
pnew = this->num*(lcm/this->den);
pnew -= r.GetP()*(lcm/r.GetQ());
return Rational(pnew, lcm);
}
const Rational Rational::operator*(const Rational &r) const {
// First remove common divisors of opposing numerators and denominators! Reduce the chance of overflow error.
// Multiplication is (a/b) * (p/q)
int a=this->num, b=this->den, p=r.GetP(), q=r.GetQ(), g;
g = gcd(a,q);
a/=g;
q/=g;
g = gcd(b, p);
b/=g;
p/=g;
return Rational(a*p, b*q);
}
