项目二 实现复数类中的运算符重载(2)

/*copyright(c)2016.烟台大学计算机学院 * All rights reserved, * 文件名称：text.Cpp * 作者：舒文超 * 完成日期：2016年5月12日 * 版本号：vc++6.0 * * 问题描述:请用类的友元函数，而不是成员            函数，再次完成上面提及的运算            符的重载。 */#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);    void display();private:    double real;    double imag;};//下面定义成员函数Complex operator+(Complex &c1,Complex &c2){    Complex c3;    c3.real=c1.real+c2.real;    c3.imag=c1.imag+c2.imag;    return c3;}Complex operator-(Complex &c1,Complex &c2){    Complex c3;    c3.real=c1.real+c2.real;    c3.imag=c1.imag+c2.imag;    return c3;}Complex operator*(Complex &c1,Complex &c2){    Complex c3;    c3.real=c1.real*c2.real;    c3.imag=c1.imag*c2.imag;    return c3;}Complex operator/(Complex &c1,Complex &c2){    Complex c3;    c3.real=c1.real/c2.real;    c3.imag=c1.imag/c2.imag;    return c3;}void Complex::display(){    if(imag>0)        cout<<real<<"+"<<imag<<"i"<<endl;    else        cout<<real<<imag<<"i"<<endl;}//下面定义用于测试的main()函数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();    return 0;}