第七周C++ 任务三。模板类设计Complex，使实部和虚部为定义对象时用的实际类型

【任务3】阅读P314的例10.1（电子版的在平台上见txt文件）。该例实现了一个复数类，但是美中不足的是，复数类的实部和虚部都固定是double型的。可以通过模板类的技术手段，设计Complex，使实部和虚部的类型为定义对象时用的实际类型。

（1）要求类成员函数在类外定义。

（2）在此基础上，再实现减法、乘法和除法

你可以使用的main()函数如下。

int main( )

{ Complex<int> c1(3,4),c2(5,-10),c3; 

 c3=c1.complex_add(c2); 

 cout<<"c1+c2=";

 c3.display( ); 

 Complex<double> c4(3.1,4.4),c5(5.34,-10.21),c6; 

 c6=c4.complex_add(c5); 

 cout<<"c4+c5=";

 c6.display( );

 system("pause");

 return 0;

}

附：例10.1的代码

#include <iostream>

using namespace std;

class Complex  

{

public:

 Complex( ){real=0;imag=0;}    

 Complex(double r,double i){real=r;imag=i;}

 Complex complex_add(Complex &c2);

 void display( );  

private:

 double real;

 double imag;

};

Complex Complex::complex_add(Complex &c2)

{

 Complex c;

 c.real=real+c2.real;

 c.imag=imag+c2.imag;

 return c;

}  

void Complex::display( )  

{

 cout<<"("<<real<<","<<imag<<"i)"<<endl;

}

int main( )

{

 Complex c1(3,4),c2(5,-10),c3; 

 c3=c1.complex_add(c2); 

 cout<<"c1="; c1.display( ); 

 

#include <iostream>
using namespace std;
template <class numtype>
class Complex
{
public:
Complex( ){real=0;imag=0;}
Complex(double r,double i){real=r;imag=i;}
Complex complex_add(Complex &c2);
Complex complex_subtract(Complex <numtype> &c2);
Complex complex_multiply(Complex <numtype> &c2);
Complex complex_divide(Complex <numtype> &c2);
void display( );
private:
double real;
double imag;
};
template <class numtype>
Complex<numtype> Complex<numtype>::complex_add(Complex <numtype> &c2)
{
Complex <numtype> c;
c.real=real+c2.real;
c.imag=imag+c2.imag;
return c;
}
template <class numtype>
Complex<numtype> Complex<numtype>::complex_subtract(Complex <numtype> &c2)
{
Complex <numtype> c;
c.real=real-c2.real;
c.imag=imag-c2.imag;
return c;
}
template <class numtype>
Complex<numtype> Complex<numtype>::complex_multiply(Complex <numtype> &c2)
{
Complex <numtype> c;
c.real=real*c2.real-imag*c2.imag;
c.imag=imag*c2.real+real*c2.imag;
return c;
}
template <class numtype>
Complex<numtype> Complex<numtype>::complex_divide(Complex <numtype> &c2)
{
Complex <numtype> c;
c.real=(real*c2.real+c2.imag*imag)/(real*real+imag*imag);
c.imag=(c2.imag*real-c2.real*imag)/(real*real+imag*imag);
return c;
}
template <class numtype>
void Complex<numtype>::display( )
{
cout<<"("<<real<<","<<imag<<"i)"<<endl;
}

int main( )
{
Complex<int> c1(3,4),c2(5,-10),c3;
c3=c1.complex_add(c2);
cout<<"c1+c2=";
c3.display( );

c3=c1.complex_subtract(c2) ;
cout<<"c1-c2=";
c3.display( );

c3=c1.complex_multiply(c2);
cout<<"c1*c2=";
c3.display( );

c3=c1.complex_divide(c2);
cout<<"c2/c1=";
c3.display( );

Complex<double>	c4(3.1,4.4),c5(5.34,-10.21),c6;
c6=c4.complex_add(c5);
cout<<"c4+c5=";
c6.display( );

c6=c4.complex_subtract(c5) ;
cout<<"c4-c5=";
c6.display( );

c6=c4.complex_multiply(c5);
cout<<"c4*c5=";
c6.display( );

c6=c4.complex_divide(c5) ;
cout<<"c5/c4=";
c6.display( );
system("pause");
return 0;
}

 



 

感言：掌握了类模板这个程序没有太大难度。

但在public里作声明时还有必要加上

Complex complex_subtract(Complex <numtype> &c2);

Complex complex_multiply(Complex <numtype> &c2);

Complex complex_divide(Complex <numtype> &c2);

 

中的<numtype>吗？