方案一

//1）方案一：請用類的成員函數完成運算符的重載；*/
#include <iostream>

using namespace std;

class Complex
{
public:
	Complex(){real=0;imag=0;}
	Complex(double r,double i){real=r;imag=i;}

	Complex operator+ (Complex &c1);
	Complex operator- (Complex &c1);
	Complex operator* (Complex &c1);
    Complex operator/ (Complex &c1);
  
	void display();
private:
	double real;
	double imag;
};
//下面定義成員函數
void Complex :: display( )    
{  
    cout<<"("<<real<<","<<imag<<"i)"<<endl;  
}  

Complex Complex :: operator + (Complex &c1)
{return Complex(real + c1.real, imag + c1.imag);}

Complex Complex :: operator - (Complex &c1)
{return Complex(real - c1.real, imag - c1.imag);}

Complex Complex :: operator * (Complex &c1)
{return Complex(real * c1.real - imag * c1.imag, imag * c1.real + real * c1.imag);}

Complex Complex :: operator / (Complex &c1)
{return Complex((real * c1.real + imag * c1.imag) / (c1.real * c1.real + c1.imag * c1.imag), (imag * c1.real - real * c1.imag) / (c1.real * c1.real + c1.imag * c1.imag));}

int main()
{
	const double d = 2;
	Complex c1(3,4), c2(5,-10), c3;
	cout << "c1=";
	c1.display();

	cout << "c2=";
	c2.display();

	c3 = c1 + c2;
	cout << "c1+c2=";
	c3.display();

	c3 = c1 - c2;
	cout << "c1-c2=";
	c3.display();

	c3 = c1 * c2;
	cout << "c1*c2=";
	c3.display();

	c3 = c1 / c2;
	cout << "c1/c2=";
	c3.display();

	system("pause");
	return 0;
}