第8周项目1-复数类中的运算符重载（续）

/*
*copyright (c)2015,烟台大学计算机学院
*All rights reserved
*文件名称：project.cpp
*作者：孙春红
*完成日期：2015年5月5日
*版本号：v1.0
*
*问题描述：在复数类中的运算符重载基础上
（1）再定义一目运算符 -，-c相当于0-c。
（2）定义Complex类中的<<和>>运算符的重载，实现输入和输出，
改造原程序中对运算结果显示方式，使程序读起来更自然。
*输入描述：略。
*程序输出：略。
*/
#include<iostream>
using namespace std;
class Complex
{
public:
    Complex()
    {
        real=0;
        imag=0;
    }
    Complex(double r,double i)
    {
        real=r;
        imag=i;
    }
    Complex operator+(const Complex &c2);
    Complex operator-(const Complex &c2);
    Complex operator*(const Complex &c2);
    Complex operator/(const Complex &c2);
    Complex operator-();
    friend ostream& operator <<(ostream& output,Complex&c);
    friend istream& operator >>(istream& input,Complex&c);
    void display();
private:
    double real;
    double imag;
};
//下面定义成员函数
Complex Complex::operator +(const Complex &c2)
{
    Complex c;
    c.real=real+c2.real;
    c.imag=imag+c2.imag;
    return c;
}
Complex Complex::operator -(const Complex &c2)
{
    Complex c;
    c.real=real-c2.real;
    c.imag=imag-c2.imag;
    return c;
}
Complex Complex::operator *(const Complex &c2)
{
    Complex c;
    c.real=real*c2.real-imag*c2.imag;
    c.imag=real*c2.imag+imag*c2.real;
    return c;
}
Complex Complex::operator /(const Complex &c2)
{
    Complex c;
    c.real=(real*c2.real+imag*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag);
    c.imag=(imag*c2.real-real*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag);
    return c ;
}
void Complex::display()
{
    cout<<"("<<real<<","<<imag<<"i)"<<endl;
}
Complex Complex::operator-()
{
    real=-real;
    imag=-imag;
    return *this;
}
ostream& operator <<(ostream& output,Complex&c)
{
    output<<"("<<c.real;
    if (c.imag>=0)
        output<<"+";
    output<<c.imag<<"i)"<<endl;
    return output;
}
istream& operator >>(istream& input,Complex&c)
{
    cout<<"请输入实部和虚部："<<endl;
    input>>c.real>>c.imag;
    return input;
}

//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();
    c3=-c1;
    cout<<"-c1=";
    cout<<c3<<endl;
    Complex c4;
    cin>>c4;
    cout<<c4<<endl;
    return 0;
}

运行结果：

知识点总结：

学会单目运算符重载，以及输入输出流的重载