第九周项目一复数类中的运算符重载（续）

/*Copyright(c)2014,烟台大学计算机学院  
 *Allrights reserved.  
 *文件名称:MADE2.cpp  
 *作    者:张生栋  
 *完成日期:2015年5月13日  
 *问题描述:定义一个定义完整的类（是可以当作独立的产品发布，成为众多项目中的“基础工程”）。 
 这样的类在(2)的基础上，扩展+、-、*、/运算符的功能，使之能与double型数据进行运算。设Complex c;  
 double d; c+d和d+c的结果为“将d视为实部为d的复数同c相加”，其他-、*、/运算符类似 ，再定义一目运算符-，-c相当于0-c，再定义<<和>>的重载
 *输入描述:两个复数
 *输出描述：略  
 *版 本 号：v1.0  
 */    

#include <iostream>

using namespace std;

class Complex
{
public:
    Complex(){real=0;imag=0;}
    Complex(double r,double i){real=r; imag=i;}
    Complex operator-();
    friend ostream& operator << (ostream& output, const Complex& c);
    friend istream& operator >> (istream& input, Complex& c);
    friend Complex operator+(Complex &c1,Complex &c2);
    friend Complex operator+(double d1,Complex &c2);
    friend Complex operator+(Complex &c1,double d2);
    friend Complex operator-(Complex &c1,Complex &c2);
    friend Complex operator-(double d1,Complex &c2);
    friend Complex operator*(Complex &c1,Complex &c2);
    friend Complex operator*(double d1,Complex &c2);
    friend Complex operator*(Complex &c1,double d2);
    friend Complex operator/(Complex &c1,Complex &c2);
    friend Complex operator/(double d1,Complex &c2);
    friend Complex operator/(Complex &c1,double d2);
private:
    double real;
    double imag;
};
//下面定义成员函数
ostream& operator << (ostream& output, const Complex& c)
{
    output<<"("<<c.real;
    if(c.imag>0)
        output<<"+";
    output<< c.imag<<"i)";
    return output;
}
istream& operator >> (istream& input, Complex& c)
{
    int a,b;
    char sign,i;
    cout<<"请输入一个复数:";
    input>>a>>sign>>b>>i;
    while(!((sign=='+'||sign=='-')&&i=='i'));
    c.real=a;
    c.imag=(sign=='+')?b:-b;
    return input;
}
Complex operator+(Complex &c1,Complex &c2)
{
    Complex c;
    c.real=c1.real+c2.real;
    c.imag=c1.imag+c2.imag;
    return c;
}
Complex operator+(double d1,Complex &c2)
{
    Complex c(d1,0);
    return c+c2;
}
Complex operator+(Complex &c1,double d2)
{
    Complex c(d2,0);
    return c1+c;
}
Complex operator-(Complex &c1,Complex &c2)
{
    Complex c;
    c.real=c1.real-c2.real;
    c.imag=c1.imag-c2.imag;
    return c;
}
Complex operator-(double d1,Complex &c2)
{
    Complex c(d1,0);
    return c+c2;
}
Complex operator-(Complex c1,double d2)
{
    Complex c(d2,0);
    return c1+c;
}
Complex operator*(Complex &c1,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;
}
Complex operator*(double d1,Complex &c2)
{
    Complex c(d1,0);
    return c*c2;
}
Complex operator*(Complex &c1,double d2)
{
    Complex c(0,d2);
    return c1*c;
}
Complex operator/(Complex &c1,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;
}
Complex operator/(double d1,Complex &c2)
{
    Complex c(d1,0);
    return c/c2;
}
Complex operator/(Complex &c1,double d2)
{
    Complex c(0,d2);
    return c1/c;
}

//下面定义用于测试的main()函数
int main()
{
    Complex c1,c2,c3;
    double d=11;
    cout<<"c1: "<<endl;;
    cin>>c1;
    cout<<"c2: "<<endl;
    cin>>c2;
    cout<<"c1="<<c1<<endl;
    cout<<"c2="<<c2<<endl;
    cout<<"d="<<d<<endl;
    //cout<<"-c1="<<(-c1);
    c3=c1+c2;
    cout<<"c1+c2="<<c3<<endl;
    cout<<"c1+d="<<(c1+d)<<endl;
    cout<<"d+c1="<<(d+c1)<<endl;
    c3=c1-c2;
    cout<<"c1-c2="<<c3<<endl;
    cout<<"c1-d="<<(c1-d)<<endl;
    cout<<"d-c1="<<(d-c1)<<endl;
    c3=c1*c2;
    cout<<"c1*c2="<<c3<<endl;
    cout<<"c1*d="<<(c1*d)<<endl;
    cout<<"d*c1="<<(d*c1)<<endl;
    c3=c1/c2;
    cout<<"c1/c2="<<c3<<endl;
    cout<<"c1/d="<<(c1/d)<<endl;
    cout<<"d/c1="<<(d/c1)<<endl;
    return 0;
}

运行结果：