第八週作業任務一方案二

請用類的友元函數，而不是成員函數，完成上面提及的運算符的重載：

#include <iostream>
using namespace std;

class Complex
{
public:
 Complex(){real=0;imag=0;}
 Complex(double r,double i){real=r;imag=i;}
 friend Complex operator+(Complex &c1,Complex &c2);
 friend Complex operator-(Complex &c1,Complex &c2);
 friend Complex operator*(Complex &c1,Complex &c2);
 friend Complex operator/(Complex &c1,Complex &c2);
 friend void display(Complex &c2);
private:
 double real;
 double imag;
};
//下面定義友元函數
//複數相加： (a+bi)+(c+di)=(a+c)+(b+d)i.   
Complex operator +(Complex &c1,Complex &c2)      
{    
 return Complex (c1.real+c2.real,c1.imag+c2.imag);
}    
    
    
//複數相減：(a+bi)-(c+di)=(a-c)+(b-d)i.         
Complex operator-(Complex &c1,Complex &c2)        
{        
   Complex c;       
    c.real=c1.real-c2.real;        
    c.imag=c1.imag-c2.imag;        
    return c;        
}        
      
//複數相乘：(a+bi)(c+di)=(ac－bd)+(bc+ad)i.     
     
Complex operator*(Complex &c2)   
{        
    Complex  c;        
    c.real=c1.real*c2.real-c1.imag*c2.imag;        
    c.imag=c1.imag*c2.real+c1.real*c2.imag;        
    return c;        
}        
      
//複數相除：(a+bi)/(c+di)=(ac+bd)/(c^2+d^2) +(bc-ad)/(c^2+d^2)i     
Complex operator/(Complex &c2)   
{        
    Complex  c;        
          c.real=(c1.real*c2.real+c1.imag*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag);  
                 c.imag=(c1.imag*c2.real-c1.real*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag);  

                            return c;  


}

  
void display(Complex &c2 )      
{    
    cout<<"("<<c2.real<<","<<c2.imag<<"i)"<<endl;    
}    

int main()
{
 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;
}