error C2100: illegal indirection in c++

class students
{
	char *stud_name;
	int rollno;
public:
	void set_values(char *n,int y)
	{
		stud_name=n;
		rollno=y;
	}
};
int main()
{
	char *name;
	int roll;
	int a;
	cout<<"enter the number of students";
	cin>>a;
	students *ptr=new students[a];
	for(int i=0;i<10;i++)
	{
		cout<<"enter the name and rollno of "<<i<<"th student";
		cin.get(name,20);
		cin>>roll;
		*(ptr+i)->set_values(name,roll);//here is the error
	}
        return 0;
}