第八周项目一任务二——实现复数类中的运算符重载（利用类的友元函数）

/*
* 程序的版权和版本声明部分
* Copyright (c)2013, 烟台大学计算机学院学生
* All rightsreserved.
* 文件名称： object.cpp
* 作者：杨晨
* 完成日期： 2013年4 月 19 日
* 版本号： v1.0
* 输入描述：无
* 问题描述：无
* 程序输出：无
*/
#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)
{
    return Complex(c1.real+c2.real,c1.imag+c2.imag);
}
Complex operator-(Complex &c1,Complex &c2)
{
    return Complex(c1.real-c2.real,c1.imag-c2.imag);
}
Complex operator*(Complex &c1,Complex &c2)
{
    return Complex(c1.real*c2.real-c1.imag*c2.imag,c1.imag*c2.real+c1.real*c2.imag);
}
Complex operator/(Complex &c1,Complex &c2)
{
    return Complex((c1.real*c2.real+c1.imag*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag),(c1.imag*c2.real+c1.real*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag));
}
void Complex::display()
{
    cout<<"("<<real<<","<<imag<<"i)"<<endl;
}

//下面是测试函数
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;
}