Program to illustrate RETURNING STRUCTURE FROM FUNCTION via Complex Number

#include<iostream.h>
#include<conio.h>
struct complex
{
 int real;
 int img;
};
complex add(complex c1,complex c2)
 {
  complex temp;
  temp.real=c1.real+c2.real;
  temp.img=c1.img+c2.img;
  return temp;
 }
complex sub(complex c1,complex c2)
 {
  complex temp;
  temp.real=c1.real-c2.real;
  temp.img=c1.img-c2.img;
  return temp;
 }
void main()
{
 clrscr();
 int op;
 complex c1,c2,c3,c4;
 cout<<"\n";
 cout<<"enter real and imaginery part";
 cout<<"\n\n";
 cin>>c1.real;
 cout<<"\n";
 cin>>c1.img;
 cout<<"\n";
 cout<<"enter real and imaginery part";
 cout<<"\n\n";
 cin>>c2.real;
 cout<<"\n";
 cin>>c2.img;
 cout<<"\n";
 cout<<"1. add \n\n2. sub";
 cout<<"\n\n";
 cout<<"enter your option";
 cout<<"\n\n";
 cin>>op;
 cout<<"\n";
 switch(op)
  {
   case 1:c3=add(c1,c2);
        cout<<c3.real<<"+i"<<c3.img;
        break;
   case 2:c4=sub(c1,c2);
        cout<<c4.real<<"+i"<<c4.img;
        break;
   default:cout<<"invalid option";
           break;
  }
 getch();
 }