Question

Write minimal code to declare a class Complex that enables operations on complex numbers, and also to overload the multiplication * operator.

Answer 1

#include<iostream>
#include<stdlib.h>
#include<string>

using namespace std;

//complex class
class complex
{
   float real;
   float img;
  
   public :

   // constructor
   complex(float r=0,float i=0)
   {
       real = r;
       img = i;
   }

   void display()
   {
       cout<<real<<"+i"<<img;
   }

   // fucntion to return the real part
   float getReal()
   {
       return real;
   }

   // function to return the imaginary part
   float getImg()
   {
       return img;
   }

   // function to over load the + operator
   complex operator + (const complex &c2)
   {
       complex dummy;
       dummy.real=real+c2.real;
       dummy.img=img+c2.img;
       return dummy;
   }
  
   // function to overload the - operator
   complex operator - (const complex &c2)
   {
       complex dummy;
       dummy.real=real-c2.real;
       dummy.img=img-c2.img;
       return dummy;
   }

   friend complex operator * (float,complex);  
   friend complex operator * (complex,float);

   //fucntion to overload the * operator for complex multiplication
   complex operator * (const complex &c)
   {
       complex dummy;
       dummy.real = real*c.real - img*c.img;
       dummy.img = c.img*real + c.real*img;
       return dummy;
   }
  
};

// complex to overload multiplication by scalar of the form
// x * (a + ib)
complex operator * (float f, complex c)
{
   complex dummy;
   dummy.real = c.real * f;
   dummy.img *= c.img * f;
   return dummy;
}

// complex to overload multiplication by scalar of the form
// (a + ib) * x
complex operator * (complex c, float f)
{
   complex dummy;
   dummy.real = c.real * f;
   dummy.img = c.img * f;
   return dummy;
}

int main()
{
   complex t1(1,2),t2(2,3);
   complex t3 = t1*2;
   t3.display();
   cout<<endl;

   t3 = t1*t2;
   t3.display();
   cout<<endl;
  
   t3=t1+t2;
   t3.display();
   cout<<endl;

   return 0;
}