第4章 第3题

#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 &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(1,5),c2(-2,-4),c3;int i=3;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;}