Can you explain the principle of a stack and its main features?

A stack is a data structure that operates on the Last In, First Out (LIFO) principle, meaning the most recently added element is the first to be removed.

Main features of a stack:

• Operations:
  • push — add an element to the top of the stack.
  • pop — remove and return the top element.
  • peek or top — view the top element without removing it.
• Uses:
  • Managing function calls (call stack).
  • Reversing the order of data processing.
  • Implementing undo actions.

Example of a simple stack in C++:

#include <iostream>
#include <stack>

int main() {
    std::stack<int> s;
    s.push(10);
    s.push(20);
    std::cout << s.top() << std::endl; // 20
    s.pop();
    std::cout << s.top() << std::endl; // 10
    return 0;
}