// Exercise about classes: implementation of complex numbers.
// Note modifiers like const and static can be used 
// ONLY for functions that are memebrs of a class. 
// Also, they cannot be used for constructors.

#include <iostream>
#include <cmath>
using namespace std;
class complex
{
public:
	float x,y;
	complex();
	complex(float x1, float y1);
	complex add(complex a, complex b) const;
	float magnitude(complex a) const;
};
int main()
{
	float m, n;
	// complex c3(); // ERROR
	complex c3;
	cout << "Enter the real part of the first complex "
		<< "number followed by the imaginary part:\n";
	cin >> m >> n;
	complex c1(m,n);
	cout << "Enter the real part of the second complex "
		<< "number followed by the imaginary part:\n";
	cin >> m >> n;
	complex c2(m,n);
	c3 = c3.add(c1,c2);
	// c3 = c1.add(c1,c2); // OK
	// c1 = c1.add(c1,c2); // OK
	cout << "The sum of the two numbers is: "
		<< c3.x << " + " << c3.y << " i.\n";
	cout << "The magnitude/length of the first is: "
		<< c1.magnitude(c1) << endl;
	cout << "The magnitude/length of the second is: "
		<< c2.magnitude(c2) << endl;

	return 0;
}
complex::complex()
{
	x = 0; y = 0;
}
complex::complex(float x1, float y1)
{
	x = x1; y = y1;
}
complex complex::add(complex a, complex b) const
{
	complex sum;
	sum.x = a.x + b.x;
	sum.y = a.y + b.y;
	return sum;
}
float complex::magnitude(complex a) const
{
	return sqrt(a.x * a.x + a.y * a.y);
}