STACK C++ ARR

/* program for stack implementation in c++ using array*/
#include <iostream>
using namespace std;

class stackk
{
    private:
        // making a stack of size 20
        int stk[20],top;

    public:
        // constructor for the class
        stackk()
        {
            top=-1;
        }

        // method to push the element onto the stack
        void push(int element)
        {
            //increment top value
            top++;

            //check if stack is full
            if(top==20)
            {
                cout<<"\nSTACKFULL!!!!!";
            }
            else
            {
                stk[top]=element;
                cout<<"\nELEMENT PUSHED!!";
            }
            return;
        }

        int pop()
        {
            int element;
            //check if stack is empty
            if(top<0)
            {
                cout<<"\nSTACKEMPTY!!!!!";
                //consider all elements are smaller than 99999
                return 99999;       //returning  99999 to indicate stackempty
            }
            else
            {
                element=stk[top];
                // decrement the top value
                top--;
                return element;
            }
        }

        //display stack contents
        void display()
        {
            int i;
            for(i=0;i<=top;i++)
                {
                    cout<<"\n"<<stk[i];
                }
        }
};

int main()
{
    int element,cont,choice;
    cont=1;
    stackk s1;

    do
    {
        cout<<"\nTHE FOLLOWING CHOICES ARE AVAILIABLE : ";
        cout<<"\n1.PUSH AN ELEMENT";
        cout<<"\n2.POP AN ELEMENT";
        cout<<"\n3.VIEW STACK CONTENTS";
        cout<<"\nENTER YOUR CHOICE : ";
        cin>>choice;

        switch(choice)
        {
            case 1:
                cout<<"\nENTER THE ELEMENT TO BE PUSHED : ";
                cin>>element;
                s1.push(element);
                break;

            case 2:
                element=s1.pop();
                if(element!=99999)
                {
                    cout<<"\nTHE ELEMENT POPPED  IS : "<<element;
                }
                break;

            case 3:
                cout<<"\nTHE ELEMENTS OF STACK ARE : ";
                s1.display();
                break;
        }
        cout<<"\nDO YOU WANT TO CONTINUE (1/0): ";
        cin>>cont;

    }while(cont==1);
    return 0;
}