Multilevel Inheritance

#include<iostream.h>
#include<conio.h>
#include<string.h>
class stu{
    protected:
        int roll;
        char name[45],course[10];
    public:
        stu(int r, char n[], char c[])
        {
            roll=r;
            strcpy(course,c);
            strcpy(name,n);
        }
};
class exam:public stu
{
    protected:
        int marks[3];
    public:
        exam(int r, char n[], char c[], int *m):stu(r,c,n)
        {
            marks[0]=*m;
            marks[1]=*(m+1);
            marks[2]=*(m+2);
        }
};
class result:public exam
{
    protected:
        int total; float avg;
    public:
        result(int r, char n[], char c[], int *m):exam(r,c,n,m)
        {
            total=marks[0]+marks[1]+marks[2];
            avg=total/3;
        }
        void display(void)
        {
            cout<<"\nName: "<<name<<"\nRoll: "<<roll<<"\nCourse: "<<course<<"\nMarks: "<<marks[0]<<' '<<marks[1]<<' '<<marks[2]<<"\nTotal= "<<total<<"\nAverage= "<<avg;
        }
};
void main()
{
    int m[]={100,98,99};
    result ob1(03,"Rahul Kumar","B.C.A",m);
    ob1.display();
    getch();
    clrscr();
}