第三題

#include<iostream>
using namespace std;
class Complex
{
	private:
		double real;
		double imag;
	public:
		void display();
		Complex(){real=0;imag=0;}
		Complex(double r,double i){real=r;imag=i;}
		Complex operator+(Complex &c2);
		Complex operator+(int &i);
		friend Complex operator+(int&,Complex &);
};
void Complex::display()
{
    cout<<"("<<real<<","<<imag<<"i)"<<endl;
}
Complex Complex::operator+(Complex &c)
{
    return Complex(real+c.real,imag+c.imag);
}
Complex Complex::operator+(int &i)
{
	return Complex(real+i,imag);
}
Complex operator+(int &i,Complex &c)
{
	return Complex(i+c.real,c.imag);
}
int main()
{
	Complex c1(2,6),c2(5,-4),c3;
	int i=2;
	cout<<"c1=";
	c1.display();
	cout<<"c2=";
	c2.display();
	c3=c1+c2;
	cout<<"c1+c2=";
	c3.display();
	c3=i+c1;
	cout<<"i+c1=";
	c3.display();
	c3=c1+i;
	cout<<"c1+i=";
	c3.display();
	return 0;
}