Stack

                                                   STACK WORKS ON THE PRINCIPLE OF FIRST-IN, LAST-OUT.

#include<iostream>
#include<stack>

using namespace std;
int main()
{
stack<string> s;                               //declaring stack

s.push("Hello");
s.push("Shaivi");
s.push("Agarwal");

cout<<"Top Element : "<<s.top()<<endl;        //to print the top element of the stack(i.e. Agarwal)
s.pop();                                      //poping out the last element which is Agarwal
cout<<"Top Element : "<<s.top()<<endl;        //now output-- Shaivi 

cout<<"Size of stack : "<<s.size()<<endl;
cout<<"Empty or not : "<<s.empty()<<endl;
}


------------------------OUTPUT----------------------
Top Element : Agarwal
Top Element : Shaivi
Size of stack : 2
Empty or not : 0