// Program: userational.cpp
// Add two rational numbers.
#include
// the new type rational
struct rational {
int n;
int d; // INV: d != 0
};
// POST: return value is the sum of a and b
rational add (const rational a, const rational b)
{
rational result;
result.n = a.n * b.d + a.d * b.n;
result.d = a.d * b.d;
return result;
}
int main ()
{
// input
std::cout << "Rational number r:\n";
rational r;
std::cout << " numerator =? "; std::cin >> r.n;
std::cout << " denominator =? "; std::cin >> r.d;
std::cout << "Rational number s:\n";
rational s;
std::cout << " numerator =? "; std::cin >> s.n;
std::cout << " denominator =? "; std::cin >> s.d;
// computation
const rational t = add (r, s);
// output
std::cout << "Sum is " << t.n << "/" << t.d << ".\n";
return 0;
}
