第九周项目一： 复数类中的运算符重载（续）

问题及代码：

/*
*Copyright (c)2014,烟台大学计算机与控制工程学院
*All rights reserved.
*文件名称： 复数类中的运算符重载（续）  .cpp
*作    者：白云飞
*完成日期：2015年5月1日
*版 本 号：v1.0
*
*问题描述：定义一个定义完整的类,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。
*程序输入：无
*程序输出：运算结果
*/
#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+(const Complex &c1,const Complex &c2);
    friend Complex operator+(double d1,const Complex &c2);
    friend Complex operator+(const Complex &c1,double d2);
    friend   Complex operator-(const Complex &c1,const Complex &c2);
    friend   Complex operator-(double d1,const Complex &c2);
    friend   Complex operator-(const Complex &c1,double d2);
    friend  Complex operator*(const Complex &c1,const Complex &c2);
    friend  Complex operator*(double d1,const Complex &c2);
    friend  Complex operator*(const Complex &c1,double d2);
    friend   Complex operator/(const Complex &c1,const Complex &c2);
    friend   Complex operator/(double d1,const Complex &c2);
    friend   Complex operator/(const Complex &c1,double d2);
private:
    double real;
    double imag;
};
//下面定义成员函数
Complex Complex::operator-()
{
    return(0-*this);
}
istream& operator>>(istream & input,Complex&c)
{
    char a,b;
    cout<<"请输入复数（a+bi或a-bi）:";
    input>>c.real>>a>>c.imag>>b;
    return input;
}
ostream& operator<<(ostream & output,const Complex&c)
{
    output<<"("<<c.real;
    if(c.imag>=0) output<<"+";
    output<<c.imag<<"i)";
    return output;
}
Complex operator+(const Complex &c1,const Complex &c2)
{
    Complex c;
    c.real=c1.real+c2.real;
    c.imag=c1.imag+c2.imag;
    return c;
}
Complex operator+(double d1,const Complex &c2)
{
    Complex c(d1,0);
    return c+c2;
}
Complex operator+(const Complex &c1,double d2)
{
    Complex c(d2,0);
    return c1+c;
}
Complex operator-(const Complex &c1,const Complex &c2)
{
    Complex c;
    c.real=c1.real-c2.real;
    c.imag=c1.imag-c2.imag;
    return c;
}
Complex operator-(double d1,const Complex &c2)
{
    Complex c(d1,0);
    return c-c2;
}
Complex operator-(const Complex &c1,double d2)
{
    Complex c(d2,0);
    return c1-c;
}
Complex operator*(const Complex &c1,const 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,const Complex &c2)
{
    Complex c(d1,0);
    return c*c2;
}
Complex operator*(const Complex &c1,double d2)
{
    Complex c(d2,0);
    return c1*c;
}
Complex operator/(const Complex &c1,const 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,const Complex &c2)
{
    Complex c(d1,0);
    return c/c2;
}
Complex operator/(const Complex &c1,double d2)
{
    Complex c(d2,0);
    return c1/c;
}
//下面定义用于测试的main()函数
int main()
{
    double d=1;
    cout<<"d="<<d<<endl;
    Complex c1(3,4),c2(5,-10),c3;
    cout<<"c1="<<c1<<endl;
    cout<<"c2="<<c2<<endl;
    cout<<"-c1="<<c1<<endl;
    cout<<"-c2="<<c2<<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;;
    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：

学习心得：

重载单目运算符，如果运算符重载函数作为成员函数，还可以省略参数。只能将重载“>>”和“<<”的函数作为友元函数，而不能将他们定义为成员函数。