P153 3

<img src="https://img-blog.youkuaiyun.com/20150427212754459?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvWXVTb25nNDg2OQ==/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center" alt="" />#include <iostream> //用VC++时改为∶#include <iostream.h> 
using namespace std; //用VC++时为取消此行
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; 
}