C++ programs to implement the Stack ADT using an array

/* Write C++ programs to implement the Stack ADT using an array */

#include<iostream>
#include<conio.h>
#include<stdlib.h>
using namespace std;
class stack
{
             int stk[5];
             int top;
      public:
             stack()
              {
                top=-1;
               }
             void push(int x)
              {
                 if(top >  4)
                       {
                           cout <<"stack over flow";
                           return;
                       }
                 stk[++top]=x;
                 cout <<"inserted" <<x;
               }
             void pop()
               {
                  if(top <0)
                   {
                         cout <<"stack under flow";
                         return;
                    }
                    cout <<"deleted" <<stk[top--];
                }
             void display()
               {
                   if(top<0)
                    {
                            cout <<" stack empty";
                            return;
                    }
                    for(int i=top;i>=0;i--)
                    cout <<stk[i] <<" ";
                }
};
 
main()
{
     int ch;
     stack st;
     while(1)
        {
             cout <<"\n1.push  2.pop  3.display  4.exit\nEnter ur choice";
             cin >> ch;
             switch(ch)
              {
               case 1:  cout <<"enter the element";
                        cin >> ch;
                        st.push(ch);
                        break;
               case 2:  st.pop();  break;
               case 3:  st.display();break;
               case 4:  exit(0);
               }
         }
return (0);
}

OUTPUTS
1.push 2.pop 3.display 4.exit
Enter ur choice2
stack under flow
1.push 2.pop 3.display 4.exit
Enter ur choice1
enter the element2
inserted2
1.push 2.pop 3.display 4.exit
Enter ur choice1
enter the element3
inserted3
1.push 2.pop 3.display 4.exit
Enter ur choice2
deleted3
1.push 2.pop 3.display 4.exit
Enter ur choice1
enter the element5
inserted5
1.push 2.pop 3.display 4.exit
Enter ur choice3
5 2
1.push 2.pop 3.display 4.exit
Enter ur choice4