Answer to Question 25B-1

Here is one answer.
// An object of type Complex is a complex number.  It has
// a real part (repart) and an imaginary part (impart).

struct Complex
{
  double repart, impart;
};


// sum(a,b,c) sets c = a + b.

void sum(const Complex& a, const Complex& b, Complex& c)
{
  c.repart = a.repart + b.repart;
  c.impart = a.impart + b.impart;
}