i want to write a program to compute the Fibonacci numbers (max 20 numbers).but i want to do it using a class.

i wrote this and i want your opinions.

it computes the Fibonacci numbers for given num and then prints the result.

should i change anything?

Code:

class fib
{
private:
int fibar[20];
public:
fib();
void create_nums(int);
void show(int);
};
void fib::show(int n)
{
for(int i=0;i<n;i++)
cout<<fibar[i]<<"\n";
}
fib::fib()
{
memset(fibar,0,sizeof(int)*20);
fibar[1]=1;
}
void fib::create_nums(int n)
{
for(int i=2;i<n;i++)
fibar[i]=fibar[i-2]+fibar[i-1];
}
main()
{
fib obj;
int num;
cout<<"give N:";
do{
cin>>num;
}while(num>20 || num<0);
obj.create_nums(num);
obj.show(num);
}