declaring a stack in c++ code example

Example 1: stack c++

stack<int> stk;
stk.push(5);
int ans = stk.top(5); // ans =5
stk.pop();//removes 5

Example 2: stack c++

#include <bits/stdc++.h> 

stack<int> stk;
stk.push(5);
int ans = stk.top(5); // ans =5
stk.pop();//removes 5