Write a C++ Program of Virtual Function

#include <iostream.h> 
 #include <conio.h> 
 const int size=10; 
 #include <string.h> 
 class country 
 { 
         protected: 
                            char cname[size]; 
                            float pprc; 
                            float Iprc; 
                            float ratio; 
         public: 
                           country(){ } 
                           virtual void getdata() 
                     { 
                               cout<<"Enter Country Name "; 
                               cin>>cname; 
                               cout<<"Enter the % of Polio "; 
                               cin>>pprc; 
                               cout<<"Enter the % of Literacy "; 
                               cin>>Iprc; 
                      } 
                           virtual void display() 
                     { 
                         cout<<"\n"; 
                         cout<<"Country Name "<<cname<<endl; 
                         cout<<"Country Polio% "<<pprc<<endl; 
                         cout<<"Country Lit. % "<<Iprc<<endl; 
                         cout<<"The Measure of Interdependency "<<float (pprc/Iprc)<<endl; 
                     } 
 }; 
            class state: public country 
     { 
   protected : 
                        char sname[size]; 
                        float spprc; 
                        float slprc; 
                        float ratio; 
  public: 
                        state() {} 
                        void getdata() 
                           { 
                                       country::getdata(); 
                                       cout<<" \n"; 
                                       cout<<"Enter State Name "; 
                                       cin>>sname; 
                                       cout<<"Enter %Age of Polio of State "; 
                                       cin>>spprc; 
                                       cout<<"Enter %Age of Lite. of State "; 
                                       cin>>slprc; 
                           } 
                                       void display() 
                                { 
                                             country::display(); 
                                             cout<<"State Name "<<sname<<endl; 
                                             cout<<"%Age of Polio of State "<<spprc<<endl; 
                                             cout<<"%Age of Lite. of State "<<slprc<<endl; 
                                             cout<<"The Measure of Interdependency "<<float (spprc/slprc)<<endl; 
                                 } 
       }; 
                      void main( ) 
              { 
                          clrscr(); 
                          country *o1; 
                          state o2; 
                          cout<<"\n"; 
                          o1= &o2; 
                          o1->getdata(); 
                          o2.display(); 
                          getch(); 
              }