第三題

#include <iostream.h>       
class Complex
 {public:
   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 display();
  private:
   double real;
   double imag;
};


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


Complex Complex::operator+(int &i)
{return Complex(real+i,imag);}


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


Complex operator+(int &i,Complex &c)
{return Complex(i+c.real,c.imag);}


int main()
{Complex c1(3,4),c2(5,-10),c3;
 int i=5;
 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;
}