std::stack is a container adaptor that gives the programmer the functionality of a stack - specifically, a LIFO (last-in, first-out) data structure.

Perfect for reversing data, depth-first searches (DFS) when used explicitly, matching brackets, and undo mechanisms.

• Push: $O(1)$
• Pop: $O(1)$
• Top: $O(1)$

cpp Standard
#include <stack>

std::stack<int> s;
s.push(1);
s.push(2);

std::cout << s.top(); // 2
s.pop();
std::cout << s.top(); // 1

• Empty Stack Pop: Trying to pop() or top() an empty stack (always check s.empty() first).
• Forgetting that pop() doesn't return the element—it just removes it.
• Using it when you need to access elements other than the top (use std::vector instead).