C++类定义与使用：复数类

代码来自《工程问题C语言求解（第四版）》，不过书里的这段代码语法错误挺多的，修改了发上来。。。

Program chapter8_8.cpp

//–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––—
//  Program chapter8_8
//
//  This program demonstrates the use of
//  the complex number class and its operations.

#include <iostream>
#include "complex.h"
using namespace std;

int main(void)
{
   //  Declare and initialize variables.
   complex c1(4,1), c2(-3,-2), c3;

   //  Print initial values.
   cout << "c1:";
   c1.print();
   cout << "c2:";
   c2.print();
   cout << "c3:";
   c3.print();

   //  Compute and print new values.
   c3 = c1 + c2;
   cout << "c1+c2 = ";
   c3.print();
   c3 = c1 - c2;
   cout << "c1-c2 = ";
   c3.print();
   c3 = c1*c2;
   cout << "c1*c2 = ";
   c3.print();
   c3 = c1/c2;
   cout << "c1/c2 = ";
   c3.print();

   //  Exit program.
   return 0;
}

complex.h

//–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––—
//  Class declaration
//
//  These statements define a class for complex numbers.
//  This declaration is stored in complex.h.

#include <iostream>
#include <cmath>
using namespace std;

class complex
{
   //  Declare function prototypes for public members.
   public:
      complex();
      complex(double a, double b);
      void print();
      void input();
      double magn(complex);
      double angle(complex);
      complex operator+(complex);
      complex operator-(complex);
      complex operator*(complex);
      complex operator/(complex);

   //  Declare private members.
   private:
      double real, imag;
};

//–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––—
// Class implementation
//
// These statements define implementation of a complex class.

// This function is the default constructor to initialize a
// complex number that is not given a value.
complex::complex()
{
   real = 0;
   imag = 0;
}

//  This function is the constructor to initialize a complex
//  number to a specified value.
complex::complex(double a, double b)
{
   real = a;
   imag = b;
}


//  This function prints a complex number.
void complex::print()
{
   if (imag > 0)
      cout << real << "+" << imag << "i" << endl;
   else
      if (imag == 0)
         cout << real << endl;
      else
         cout << real << imag << "i" << endl;
}

//  This function reads two values for a complex number.
void complex::input()
{
   cin >> real >> imag;
}

//  This function defines the sum of complex numbers.
complex complex::operator+(complex c)
{
   //  Definition of complex addition.
   complex temp;
   temp.real = c.real + real;
   temp.imag = c.imag + imag;
   return temp;
}

//  This function defines the difference of complex numbers.
complex complex::operator-(complex c)
{
   // Definition of complex subtraction.
   complex temp;
   temp.real = real - c.real;
   temp.imag = imag - c.imag;
   return temp;
}

//  This function defines the product of complex numbers.
complex complex::operator*(complex c)
{
   // Definition of complex multiplication.
   complex temp;
   temp.real = (real*c.real - imag*c.imag);
   temp.imag = (imag*c.real + real*c.imag);
   return temp;
}

//  This function defines the quotient of complex numbers.
complex complex::operator/(complex c)
{
   // Definition of complex division.
   complex temp;
   temp.real = (real*c.real + imag*c.imag)/
               (pow(c.real,2) + pow(c.imag,2));
   temp.imag = (imag*c.real - real*c.imag)/
               (pow(c.real,2) + pow(c.imag,2));
   return temp;
}
//–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––—

书中电子资源网址：

Computer Science Resources | Pearson (pearsoncmg.com)