C++ - Stacks Part 1: Introduction to Stacks

A stack is a container adapter that provides restricted access to its elements. You can only push, pop, or peek at the top element.

Examples and Explanation

Basic Stack Declaration

#include <iostream>

#include <stack>

int main() {

    std::stack<int> myStack; // Creates an empty stack

    return 0;

}

Explanation: The std::stack is declared with a specific data type (e.g., int, string). The default underlying container is std::deque.

Adding Elements

myStack.push(10); // Pushes 10 onto the stack

myStack.push(20); // Pushes 20 onto the stack

Explanation: The push() method adds elements to the top of the stack.

Checking Stack Size

std::cout << "Size: " << myStack.size(); // Output: 2

Explanation: The size() method returns the number of elements currently in the stack.