Câu 1, câu 3 trong de thi

Đề Câu 1 : [You must be registered and logged in to see this link.]
//Cau 1: Thiet ke lop CHangHoa,co cac thuoc tinh la mahang,tenhang,soluong,giaban
//Xay dung cac phuong thuc : xuat , nhap , ham tao , ham huy , tinh tong tien(tong tien = so luong*giaban)
//Giai:
#include<conio.h>
#include<iostream.h>
#include<string.h>
class CHangHoa
{
private:
int mahang;
char tenhang[10];
int soluong;
int giaban;
public:
void nhap();
void xuat();
CHangHoa(){}
CHangHoa(int ma,char *ten,int so,int gia)
{
mahang=ma;
strcpy(tenhang,ten);
soluong=so;
giaban=gia;
}
void tongtien();
};
void CHangHoa::nhap()
{
cout<<"Nhap ma hang: ";cin>>mahang;
cout<<"Nhap ten hang: ";cin>>tenhang;
cout<<"Nhap so luong: ";cin>>soluong;
cout<<"Nhap gia ban: ";cin>>giaban;
}
void CHangHoa::xuat()
{
cout<<"Ma hang : "<<mahang;
cout<<"Ten hang : "<<tenhang;
cout<<"So luong: "<<soluong;
cout<<"Gia ban: "<<giaban;
}

void CHangHoa::tongtien()
{
int t;
t=soluong*giaban;
cout<<"Tong tien la: "<<t;
}

void main()
{
clrscr();
CHangHoa a;
a.nhap();
a.xuat();
a.tongtien();
getch();
}

file download :http://www.mediafire.com/?fdb44n99bihmk94
#include<conio.h>
#include<iostream.h>
#include<string.h>
class CTauthuy
{
char tenTh[20];
int vantoc;
int taitrong;
char mucdich[50];

public:
CTauthuy(char *th,int v,int k,char *m) //Ha?m Kh??i ta?o
{
strcpy(tenTh,th);
vantoc=v;
taitrong=k;
strcpy(mucdich,m);
}
CTauthuy(){}//ha?m Hu?y
virtual void Nhap();
virtual void Xuat();
};
void CTauthuy::Nhap()
{
cout<<"Ten tau thuy : ";cin>>tenTh;
cout<<"\nToc do : ";cin>>vantoc;
cout<<"\nTai trong toi da : ";cin>>taitrong;
cout<<"\nMuc dich su dung : ";cin>>mucdich;

}
void CTauthuy::Xuat()
{
cout<<"Ten tau : "<<tenTh;
cout<<"\nToc do : "<<vantoc;
cout<<"\nTai trong toi da :"<<taitrong;
cout<<"\nMuc dich su dung : "<<mucdich;
}
class CMaybay
{
char tenMB[20] ;
int phihanhdoan;
int trongluong;
int tocdo;
public:
CMaybay(char *mb,int phd,int tl,int td)//Kh??i ta?o
{
strcpy(tenMB,mb);
phihanhdoan=phd;
trongluong=tl;
tocdo=td;
}
CMaybay(){}
virtual void Nhap();
virtual void Xuat();
};
void CMaybay::Nhap()
{
cout<<"Nhap ten may bay :";cin>>tenMB;
cout<<"\nPhi hanh doan gom : ";cin>>phihanhdoan;
cout<<"\nTrong luong : ";cin>>trongluong;
cout <<"\nToc do : ";cin>>tocdo;
}
void CMaybay::Xuat()
{
cout<<"Ten may bay : "<<tenMB;
cout<<"\nPhi hanh doan gom : "<<phihanhdoan;
cout<<"\nTrong luong may bay : "<<trongluong;
cout<<"\nToc do dat duoc : "<<tocdo;
}
class CTausanbay : virtual public CTauthuy,public CMaybay
{
public:
void Nhap();
void Xuat();
};

void CTausanbay::Nhap()
{
CTauthuy::Nhap();
CMaybay::Nhap();
}
void CTausanbay::Xuat()
{
CTauthuy::Xuat();
CMaybay::Xuat();
}
void main()
{
clrscr();
CTausanbay a;
a.Nhap();
a.Xuat();
getch();
}