Наследование нескольких переменных

#include "stdafx.h"
#include <cstdlib>
#include <iostream>
#include <conio.h>
#include <string.h>
 
using namespace std;
 
class computer {           
public:
    computer();
    int ram;
    char name[20];
    void showcomp(){ cout << " ram " << ram << endl << " name " << name << endl; }
    
};
computer::computer() {            
    cout << " Input ram :"; cin >> ram;
    cout << " Input name :"; cin >> name;
}
 
class pc : public  computer {     
public:
    pc();
    int rom;
    int size;
    void showpc(){ cout << " size " << size << endl << " rom " << rom << endl; showcomp(); }
    pc(int ram, char name) :computer(ram,name){}
};
 
pc::pc() {                
    cout << " Input rom :"; cin >> rom;
    cout << " Input size :"; cin >> size;
}
 
class pda : public pc{    
public:
    pda();
    int ppi;
    int cam;
    pda(int ram, char name, int rom, int size) : pc(ram,  name, rom, size){};
    void showpda(){ cout << " ppi " << ppi << endl << " cam " << cam << endl;  showpc(); }
};
pda::pda() {         
    cout << " Input ppi :"; cin >> ppi;
    cout << " Input cam :"; cin >> cam;
}
 
int main(int argc, char *argv[])
{   pda *spisok;
    spisok = new pda[1];
    spisok[0].showpda();
        system("PAUSE");
    return EXIT_SUCCESS;
}