第八周实验指导任务1--实现复数类中的运算符重载
/* (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：定义一个复数类重载运算符+、-、*、/，使之能用于复数的加减乘除。
* 作 者： 雷恒鑫
* 完成日期： 2012 年 04 月 05 日
* 版 本 号： V1.0
* 对任务及求解方法的描述部分
* 输入描述：
* 问题描述：
* 程序输出：
* 程序头部的注释结束
*/
方案一：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
//复数相加： (a+bi)+(c+di)=(a+c)+(b+d)i.
Complex Complex::operator+(Complex &c2)
{
Complex c;
c.real=real+c2.real;
c.imag=imag+c2.imag;
return c;
}
//复数相减：(a+bi)-(c+di)=(a-c)+(b-d)i.
Complex Complex::operator-(Complex &c2)
{
Complex c;
c.real=real-c2.real;
c.imag=imag-c2.imag;
return c;
}
//复数相乘：(a+bi)(c+di)=(ac－bd)+(bc+ad)i.
Complex Complex::operator*(Complex &c2)
{
Complex c;
c.real=real*c2.real-imag*c2.imag;
c.imag=imag*c2.real+real*c2.imag;
return c;
}
//复数相除：(a+bi)/(c+di)=(ac+bd)/(c^2+d^2) +(bc-ad)/(c^2+d^2)i
Complex Complex::operator/(Complex &c2)
{
Complex c;
double d=c2.real*c2.real+c2.imag*c2.imag;
c.real=(real*c2.real+imag*c2.imag)/d; //此处有危险未排除：除法溢出
c.imag=(imag*c2.real-real*c2.imag)/d;
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：
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);
friend void display(Complex &c2);
private:
double real;
double imag;
};
//下面定义友元函数
//复数相加： (a+bi)+(c+di)=(a+c)+(b+d)i.
Complex operator+(Complex &c1,Complex &c2)
{
Complex c;
c.real=c1.real+c2.real;
c.imag=c1.imag+c2.imag;
return c;
}
//复数相减：(a+bi)-(c+di)=(a-c)+(b-d)i.
Complex operator-(Complex &c1,Complex &c2)
{
Complex c;
c.real=c1.real-c2.real;
c.imag=c1.imag-c2.imag;
return c;
}
//复数相乘：(a+bi)(c+di)=(ac－bd)+(bc+ad)i.
Complex operator*(Complex &c1,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;
}
//复数相除：(a+bi)/(c+di)=(ac+bd)/(c^2+d^2) +(bc-ad)/(c^2+d^2)i
Complex operator/(Complex &c1,Complex &c2)
{
Complex c;
double d=c2.real*c2.real+c2.imag*c2.imag;
c.real=(c1.real*c2.real+c1.imag*c2.imag)/d; //此处有危险未排除：除法溢出
c.imag=(c1.imag*c2.real-c1.real*c2.imag)/d;
return c;
}
void display(Complex &c2)
{
cout<<"("<<c2.real<<","<<c2.imag<<"i)"<<endl;
}
int main()
{
Complex c1(3,4),c2(5,-10),c3;
cout<<"c1=";
display(c1);
cout<<"c2=";
display(c2);
c3=c1+c2;
cout<<"c1+c2=";
display(c3);
c3=c1-c2;
cout<<"c1-c2=";
display(c3);
c3=c1*c2;
cout<<"c1*c2=";
display(c3);
c3=c1/c2;
cout<<"c1/c2=";
display(c3);
system("pause");
return 0;
}
运行结果：
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，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 &c2);
friend Complex operator*(Complex &c1,Complex &c2);
friend Complex operator/(Complex &c1,Complex &c2);
friend Complex operator+(Complex &c1,const double &d);
friend Complex operator+(const double &d, Complex &c);
friend void display(Complex &c2);
private:
double real;
double imag;
};
//下面定义友元函数
//复数相加： (a+bi)+(c+di)=(a+c)+(b+d)i.
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,const double &d)
{
return Complex(c1.real+d, c1.imag);
}
Complex operator+(const double &d, Complex &c1)
{
return Complex(c1.real+d, c1.imag);
}
//复数相减：(a+bi)-(c+di)=(a-c)+(b-d)i.
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 &c2)
{
return Complex(-c2.real, -c2.imag);
}
//复数相乘：(a+bi)(c+di)=(ac－bd)+(bc+ad)i.
Complex operator*(Complex &c1,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;
}
//复数相除：(a+bi)/(c+di)=(ac+bd)/(c^2+d^2) +(bc-ad)/(c^2+d^2)i
Complex operator/(Complex &c1,Complex &c2)
{
Complex c;
double d=c2.real*c2.real+c2.imag*c2.imag;
c.real=(c1.real*c2.real+c1.imag*c2.imag)/d; //此处有危险未排除：除法溢出
c.imag=(c1.imag*c2.real-c1.real*c2.imag)/d;
return c;
}
void display(Complex &c2)
{
cout<<"("<<c2.real<<","<<c2.imag<<"i)"<<endl;
}
int main()
{
Complex c1(3,4),c2(5,-10),c3,c4;
cout<<"c1=";
display(c1);
cout<<"c2=";
display(c2);
c3=c1+c2;
cout<<"c1+c2=";
display(c3);
c3=c1-c2;
cout<<"c1-c2=";
display(c3);
c3=c1*c2;
cout<<"c1*c2=";
display(c3);
c3=c1/c2;
cout<<"c1/c2=";
display(c3);
c4=c1+3.14;
cout<<"c1+3.14=";
display(c4);
c4=3.14+c1;
cout<<"3.14+c1=";
display(c4);
c4=-c1;
cout<<"-c1=";
display(c4);
system("pause");
return 0;
}
运行结果：
经验积累：
1.老师：在声明friend Complex operato+ (Complex &c, const double &d)函数时为什么要在double &d前加const，不加const为什么会出现错误？