第八周任务一

实现复数类中的运算符重载
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；

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

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;
}

解答：

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

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.real*c2.real+c2.imag*c2.imag);
	c.imag=(c2.real*imag-real*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag);
	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;
}

（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)
{
	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.real*c2.imag+c1.imag*c2.real);
}
Complex operator/(Complex &c1,Complex &c2)
{
	return Complex  ((c1.real*c2.real+c1.imag*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag),(c2.real*c1.imag-c1.real*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag));
}

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;
}

 

#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+ (double a,Complex &b);
	friend Complex operator+ (Complex &b,double a);


	friend Complex operator- (Complex &c1,Complex &c2);
	friend Complex operator- (double a,Complex &b);
	friend Complex operator- (Complex &b,double a);

	friend Complex operator* (Complex &c1,Complex &c2);
	friend Complex operator* (double a,Complex &b);
	friend Complex operator* (Complex &b,double a);

	friend Complex operator/ (Complex &c1,Complex &c2);
	friend Complex operator/ (double a,Complex &b);
	friend Complex operator/ (Complex &b,double a);


	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+ (double a,Complex &b)
{
	return Complex (a+b.real,b.imag);
}

Complex operator+ (Complex &b,double a)
{
	return Complex (b.real+a,b.imag);
}

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



Complex operator- (double a,Complex &b)
{
	return Complex (a-b.real,-b.imag);
}

Complex operator- (Complex &b,double a)
{
	return Complex ( b.real-a,b.imag);
}

Complex operator*(Complex &c1,Complex &c2)
{
	return Complex (c1.real*c2.real-c1.imag*c2.imag,c1.real*c2.imag+c1.imag*c2.real);
}

Complex operator* (double a,Complex &b)
{
	return Complex (a*b.real,a*b.imag);
}

Complex operator* (Complex &b,double a)
{
	return Complex ( b.real * a, b.imag * a );
}

Complex operator/(Complex &c1,Complex &c2)
{
	return Complex  ((c1.real*c2.real+c1.imag*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag),(c2.real*c1.imag-c1.real*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag));
}

Complex operator/ (double a,Complex &b)
{
	return Complex ((a*b.real)/(b.real*b.real+b.imag*b.imag), b.imag/(b.real*b.real+b.imag*b.imag));
}

Complex operator/ (Complex &b,double a)
{
	return Complex(b.real/a,b.imag/a);
}

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+1.2;
	cout<<"c1+1.2=";
	c3.display();
	c3=1+c1;
	cout<<"1+c1=";
	c3.display();
	c3=c1-c2;
	cout<<"c1-c2=";
	c3.display();
	c3=1-c2;
	cout<<"1-c2=";
	c3.display();
	c3=c1*c2;
	cout<<"c1*c2=";
	c3.display();
	c3=2*c1;
	cout<<"2*c1=";
	c3.display();
	c3=c1/c2;
	cout<<"c1/c2=";
	c3.display();
	c3=c2/2;
	cout<<"c2/2=";
	c3.display();
	system("pause");
	return 0;
}

上机感言：写完程序改错已成习惯，如果没错会显得不自然。笔试该咋办呢？？