/*ALGORITHM:bth insertion nd deletion is at one end only
insertion:-frst check if array is empty to enter element nd if yes thn enter
deletion:-frst check if array has somethng to delte if yes decrease top by 1
*/

#include<iostream>
#include<conio.h>
using namespace std;
const int size=5;
class stack
{
int a[size];
int top; //used to traverse in array nd store topmost elemnt
public:
stack()
{
top=-1; //array indexing starts from 0 thus initialisong top=-1 implies array to be empty
}
void ins();
void del();
void display();
};

void stack::ins()
{
int ele;
if(top==size-1) //to check whether array is already full(if true no space to insert)
{
cout<<"\nOVERFLOW ERROR..."<<endl;
return;
}
else
{
cout<<"ENTER ELEMENT";
cin>>ele;
a[++top]=ele; //++top beacuzz initialy top=-1 nd to enter element frst elemnt at index no 0 v frst increase thn write
}
}
void stack::del()
{
if(top==-1) //to check whther array is empty(no element wud b there to delete)
{
cout<<"\nUNDERFLOW ERROR..."<<endl;
return;
}
else
{
cout<<a[top]<<" deleted.."<<endl;
top--; //top is decremented implies now the elemnt at current index=top is nt prt of array whn nxt tym insert func wud b called it wud be overwrited
}
}
void stack::display()
{
for(int i=top;i>=top;i--)
{
cout<<a[i]<<" ";
}

}

int main()
{
int choice;
char ans;
stack s;
do
{
cout<<"MENU:"<<endl
<<"1.INSERT"<<endl
<<"2.DELETE"<<endl
<<"3.DISPLAY"<<endl
<<"4.EXIT"<<endl<<endl;
cout<<"ENTER YOUR CHOICE:";
cin>>choice;
switch(choice)
{
case 1:
s.ins();
break;
case 2:
s.del();
break;
case 3:
s.display();
break;
case 4:
exit(0);
}
cout<<"\nDO YOU WANT TO GO BACK TO MAIN MENU:";
cin>>ans;
}while(ans!='n');

getch();
return 0;
}