第九周项目1——复数类中的运算符重载（续）

/*
*Copyright (c)2015,烟台大学计算机与控制工程学院
*All rights reserved.
*文件名称：complex.cpp
*作    者：赵敏
*完成日期：2015年5月12日
*版 本 号：v1.0
*
*问题描述：请用友元函数，定义复数类重载运算符+、-、*、/，使之能用于复数的加减乘除
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。再定义一目运算符 -，-c相当于0-c
*/
#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,const Complex &c2);
friend Complex operator-(Complex &c1,const Complex &c2);
friend Complex operator*(Complex &c1,const Complex &c2);
friend Complex operator/(Complex &c1,const Complex &c2);
friend Complex operator+(double d,Complex &c2);
friend Complex operator-(double d,Complex &c2);
friend Complex operator*(double d,Complex &c2);
friend Complex operator/(double d,Complex &c2);
Complex operator-();
friend ostream& operator << (ostream& output, const Complex& c);
friend istream& operator >> (istream& input, Complex& c);
private:
double real;
double imag;
};
//下面定义成员函数
Complex operator+(double d,Complex &c2)
{
return Complex(d+c2.real,c2.imag);
}
Complex operator-(double d,Complex &c2)
{
return Complex(d-c2.real,c2.imag);
}
Complex operator*(double d,Complex &c2)
{
return Complex(d*c2.real,d*c2.imag);
}
Complex operator/(double d, Complex &c2)
{
Complex c(d,0);
return c/c2;
}
Complex operator/(Complex &c1, double d)
{
Complex c(d,0);
return c1/c;
}

Complex operator+(Complex &c1,const Complex &c2)
{
Complex c;
c.real=c1.real+c2.real;
c.imag=c1.imag+c2.imag;
return c;
}
Complex operator-(Complex &c1,const Complex &c2)
{
Complex c;
c.real=c1.real-c2.real;
c.imag=c1.imag-c2.imag;
return c;
}
Complex operator*(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/(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 Complex::operator-()
{
return(0-*this);
}
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;
do
{
cout<<"input a complex number(a+bi或a-bi):";
input>>a>>sign>>b>>i;
}
while(!((sign=='+'||sign=='-')&&i=='i'));
c.real=a;
c.imag=(sign=='+')?b:-b;
return input;
}
//下面定义用于测试的main()函数
int main()
{
Complex c1,c2,c3;
double d=11;
cin>>c1;
cin>>c2;
c3=c1+c2;
cout<<"c1+c2=";
cout<<c3<<endl;
c3=c1-c2;
cout<<"c1-c2=";
cout<<c3<<endl;
c3=c1*c2;
cout<<"c1*c2=";
cout<<c3<<endl;
c3=c1/c2;
cout<<"c1/c2=";
cout<<c3<<endl;
cout<<"d="<<d<<endl<<endl;
cout<<"下面是重载运算符的计算结果: "<<endl;
cout<<"d+c1=";
cout<<(d+c1)<<endl;
cout<<"d-c1=";
cout<<(d-c1)<<endl;

return 0;
}