program to use virtual functions to find area of rectangle implemented in derived class by using pointer of base class

#include<iostream.h>
#include<conio.h>
class sqr
{
    int a;
    public:
    virtual void getdata()
    {
        cout<<"\nenter the value of side ";
        cin>>a;
    }
    virtual int area()
    {
        int arr;
        arr=a*a;
        return(arr);
    }
    virtual void display()
    {
        cout<<"\narea of square :"<<area();
    }
};
class rect:public sqr
{
    private: int a,b;
    public:
    void getdata()
    {
    cout<<"enter the value of a,b ";
    cin>>a>>b;
    }
    int area()
    {
        int arr;
        arr=a*b;
        return(arr);
    }
    void display()
    {
        cout<<"\narea of rectangle "<<area();
    }
};
void main()
{
    class rect y;
    sqr x,*p;
    clrscr();
    p=&x;
    p=&y;
    p->getdata();
    p->display();
    getch();
}