第八周任务一：运算符的重载

* (程序头部注释开始)

* 程序的版权和版本声明部分

* Copyright (c) 2011, 烟台大学计算机学院学生

* All rights reserved.

* 文件名称：

* 作者：吴瑕

* 完成日期： 2012年 04月 03日

* 版本号：

*对任务及求解方法的描述部分

* 输入描述：
定义一个复数类重载运算符+、‐、*、/，使之能用于复数的加减乘除。
（1）方案一：请用类的成员函数完成运算符的重载；

#include<iostream>
using namespace std;
class Complex
{
public:
Complex(){real=0;imag=0;}
Complex(double r,double i){real=r;imag=i;}
Complex operator+(Complex &c2);
Complex operator-(Complex &c2);
Complex operator*(Complex &c2);
Complex operator/(Complex &c2);
void display();
private:
double real;
double imag;
};
//下面定义成员函数

Complex Complex::operator+(Complex &c2)
{
Complex c1;
c1.real=real+c2.real;
c1.imag=imag+c2.imag;
return c1;

}
Complex Complex::operator-(Complex &c2)
{
Complex c1;
c1.real=real-c2.real;
c1.imag=imag-c2.imag;
return c1;

}
Complex Complex::operator*(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/(Complex &c2)
{
Complex c;
c.real=(real*(c2.real)+imag*c2.imag)/((c2.imag*c2.imag)+real*real);
c.imag=(imag*c2.real-real*c2.imag)/((c2.imag*c2.imag)+real*real);
return c;
}
void Complex::display()
{
cout<<"("<<real<<","<<imag<<"i)"<<endl;
}

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();
system("pause");
return 0;
}

运行结果：

（2）方案二：请用类的友元函数，而不是成员函数，完成上面提及的运算符的重载；

#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)
{
Complex c;
c.real=c1.real+c2.real;
c.imag=c1.imag+c2.imag;
return 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*(Complex c1,Complex &c2)
{
Complex c;
c.real=c1.real*c2.real-c1.imag*c2.imag;
c.imag=c1.real*c2.imag+c1.imag*c2.real;
return c;
}
Complex operator/(Complex c1,Complex &c2)
{
Complex c;
c.real=(c1.real*(c2.real)+c1.imag*c2.imag)/((c2.imag*c2.imag)+c1.real*c1.real);
c.imag=(c1.imag*c2.real-c1.real*c2.imag)/((c2.imag*c2.imag)+c1.real*c1.real);
return c;
}
void Complex::display()
{
cout<<"("<<real<<","<<imag<<"i)"<<endl;
}

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();
system("pause");
return 0;
}

运行结果：



（3）方案三：在方案二的基础上，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
运算”的结果（其中?为+、
‐、*、/之一）。另外，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,Complex &c2);
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,double d);
friend Complex operator-(Complex c1,double d);
friend Complex operator*(Complex c1,double d);
friend Complex operator/(Complex c1,double d);
friend Complex operator-(Complex c1);
void display();
private:
double real;
double imag;
};
//下面定义成员函数
Complex operator+(Complex c1,Complex &c2)
{
Complex c;
c.real=c1.real+c2.real;
c.imag=c1.imag+c2.imag;
return 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*(Complex c1,Complex &c2)
{
Complex c;
c.real=c1.real*c2.real-c1.imag*c2.imag;
c.imag=c1.real*c2.imag+c1.imag*c2.real;
return c;
}
Complex operator/(Complex c1,Complex &c2)
{
Complex c;
c.real=(c1.real*(c2.real)+c1.imag*c2.imag)/((c2.imag*c2.imag)+c1.real*c1.real);
c.imag=(c1.imag*c2.real-c1.real*c2.imag)/((c2.imag*c2.imag)+c1.real*c1.real);
return c;
}

Complex operator+(Complex c1,double d)
{
Complex c;
c.real=c1.real+d;
c.imag=c1.imag;
return c;

}
Complex operator-(Complex c1,double d)
{
Complex c;
c.real=c1.real-d;
c.imag=c1.imag;
return c;

}
Complex operator*(Complex c1,double d)
{
Complex c;
c.real=c1.real*d;
c.imag=c1.imag*d;
return c;
}
Complex operator/(Complex c1,double d)
{
Complex c;
c.real=c1.real/d;
c.imag=c1.imag/d;
return c;
}
void Complex::display()
{
cout<<"("<<real<<","<<imag<<"i)"<<endl;
}

Complex operator-(Complex c1)
{
Complex c;
c.real=-c1.real;
c.imag=-c1.imag;
return c;
}
int main()
{
Complex c1(3,4),c2(5,-10),c3;
double d=5.1;

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+d;
cout<<"c1+d=";
c3.display();

c3=c1-d;
cout<<"c1-d=";
c3.display();

c3=c1*d;
cout<<"c1*d=";
c3.display();

c3=c1/d;
cout<<"c1/d=";
c3.display();

c3=-c1;
cout<<"-c1=";
c3.display();

system("pause");
return 0;
}

运行结果：



上机感言：

运算符的重载实质上就是为某一要用的运算符赋予一定的功能，使其实现自己要实现的运算。运算符的重载可读性强！

在实现友元函数时括号内忘了该怎么正确书写，最后出了好多错误啊！不过我感觉它出的值，下次就记住了，不会再犯这样的错误了！