// complex4.cpp
// a class that models a complex number data type

#include <iostream.h>
#include <iomanip.h>

class complex_number
{
  private:
    float real;          // real part
    float imaginary;     // imaginery part
  public:
    void set()
    {
      char dummy;        // for comma

      cout << "Enter number (format Re, Im): ";
      cin >> real >> dummy >> imaginary;
    }

    void display()
    {
      cout << '('
           << showpoint
           << setprecision(6) << real       // real part
           << ','
           << setprecision(6) << imaginary  // imaginary part
           << ')';
    }

    // add to the complex number another one (compl_num)
    complex_number add(complex_number compl_num)
    {
      complex_number cn;
      cn.real = real + compl_num.real;
      cn.imaginary = imaginary + compl_num.imaginary;

      return cn;
    }

    // subtract from the complex number another one (compl_num)
    complex_number sub(complex_number compl_num)
    {
      complex_number cn;
      cn.real = real - compl_num.real;
      cn.imaginary = imaginary - compl_num.imaginary;

      return cn;
    }

    // multiply two complex numbers and assign the result to third one
    complex_number mult(complex_number compl_num)
    {
      complex_number cn;

      cn.real = real*compl_num.real - imaginary*compl_num.imaginary;
      cn.imaginary = real*compl_num.imaginary + compl_num.real*imaginary;

      return (cn);
    }

    // divide the complex number by another one (compl_num)
    complex_number div(complex_number compl_num)
    {
      complex_number cn;

      cn.real = real;
      cn.imaginary = imaginary;

      float sqr_mod = compl_num.module();
      if (sqr_mod == 0)
      {
        cout << "Devision by zero!" << endl;
        return cn;
      }

      sqr_mod *= sqr_mod;

      cn.real = (real*compl_num.real + compl_num.imaginary*imaginary)/sqr_mod;
      cn.imaginary = (compl_num.real*imaginary - real*compl_num.imaginary)/sqr_mod;

      return cn;
    }

    // calculate the module of the complex number
    float module()
    {
      float m = real*real + imaginary*imaginary;
      return sqrt(m);
    }
    
};  // class complex_number

void main()
{
  // create three complex_number variables
  complex_number c1, c2, c3;
  char choice;

  do
  {
    // enter c1
    cout << "For c1, ";
    c1.set();       // set c1

    // enter c1
    cout << "For c2, ";
    c2.set();       // set c2

    // perform addition and ...
    c3 = c1.add(c2);
    // ... display the result
    c1.display();
    cout << " + ";
    c2.display();
    cout << " = ";
    c3.display();
    cout << endl << endl;

    // perform subtraction and ...
    c3 = c1.sub(c2);
    // ... display the result
    c1.display();
    cout << " - ";
    c2.display();
    cout << " = ";
    c3.display();
    cout << endl << endl;

    // perform multiplication and ...
    c3 = c1.mult(c2);
    // ... display the result
    c1.display();
    cout << " * ";
    c2.display();
    cout << " = ";
    c3.display();
    cout << endl << endl;

    // perform division and ...
    c3 = c1.div(c2);
    // ... display the result
    c1.display();
    cout << " + ";
    c2.display();
    cout << " / ";
    c3.display();
    cout << endl << endl;

    cout << "\nDo another (y/n)? ";
    cin >> choice;
  } while(choice != 'n');

}  //end main