Использование классов

#include <iostream>
#define N 5
using namespace std;
class electronic_store 
{   
    char item[50];
    int price;
    int number;
    int section;
    
public:
    void define();              
    int get_price(){ return price;}
    int get_sec(){ return section;}
    class electronic_store *st_ob;       
    electronic_store();             
    ~electronic_store();                
    int section_sum(int sec);   
};
 
int main()
{
    electronic_store obj;
    for(int i=0; i<N; i++)
        obj.st_ob[i].define();
    cout<<"Input section needed ";
    int s;
    cin >> s;
    cout<<"The sum of needed section items is "<<obj.section_sum(s);
    cout<<endl;
    system("PAUSE");
    return 0;
};
 
void electronic_store::define()
{
        cout<<"Input an item: ";cin>>item;
        cout<<"Input a price: ";cin>>price;
        cout<<"Input an number: ";cin>>number;
        cout<<"Input a section: ";cin>>section;
        cout<<endl;
}
electronic_store::electronic_store()
{
    st_ob = new electronic_store[N];
}
int electronic_store::section_sum(int sec)
{
    int sum=0;
    for(int i=0; i<N; i++)
        if(st_ob[i].get_sec()==sec) sum+=st_ob[i].get_price();//
    return sum;
}
electronic_store::~electronic_store()
{
    delete [] st_ob;
}

electronic_store::electronic_store()
{
    st_ob = new electronic_store[N];
}

#include <iostream>
#define N 5
using namespace std;
class store    
{                   
    char item[50];
    int price;
    int number;
    int section;
public:
    void define();              
    int get_price(){ return price;}
    int get_sec(){ return section;}
};
class electronic_store 
{               
public:
    class store *st_ob;      
    electronic_store();             
    ~electronic_store();                
    int section_sum(int sec);   
};
 
int main()
{
    electronic_store obj;
    for(int i=0; i<N; i++)
        obj.st_ob[i].define();
    cout<<"Input section needed ";
    int s;
    cin >> s;
    cout<<"The sum of needed section items is "<<obj.section_sum(s);
    cout<<endl;
    system("PAUSE");
    return 0;
};
 
void store::define()
{
        cout<<"Input an item: ";cin>>item;
        cout<<"Input a price: ";cin>>price;
        cout<<"Input an number: ";cin>>number;
        cout<<"Input a section: ";cin>>section;
        cout<<endl;
}
electronic_store::electronic_store()
{
    st_ob = new store[N];
}
int electronic_store::section_sum(int sec)
{
    int sum=0;
    for(int i=0; i<N; i++)
        if(st_ob[i].get_sec()==sec) sum+=st_ob[i].get_price();//
    return sum;
}
electronic_store::~electronic_store()
{
    delete [] st_ob;
}