how to implement stack c 2b 2b

1#include <bits/stdc++.h> 
2
3stack<int> stk;
4stk.push(5);
5int ans = stk.top(5); // ans =5
6stk.pop();//removes 5

1// CPP program to illustrate 
2// Implementation of push() function 
3#include <iostream> 
4#include <stack> 
5using namespace std; 
6  
7int main() 
8{ 
9    // Empty stack 
10    stack<int> mystack; 
11    mystack.push(0); 
12    mystack.push(1); 
13    mystack.push(2); 
14  
15    // Printing content of stack 
16    while (!mystack.empty()) { 
17        cout << ' ' << mystack.top(); 
18        mystack.pop(); 
19    } 
20} 
21