Stack

In computer science, a stack is a linear data structure that follows the Last In, First Out (LIFO) principle. This means that the last element added to the stack is the first one to be removed.

How a Stack Works

Think of a stack as a pile of books. You can only put a new book on top of the pile or remove the book from the top, one at a time. You cannot access or modify any other book in the pile until you remove the topmost book.

Stack Operations

A stack typically supports two main operations:

1. Push: Adds an element to the top of the stack.
2. Pop: Removes the topmost element from the stack.

Additionally, a stack can provide the following operations:

• Peek: Returns the value of the topmost element without removing it.
• isEmpty: Checks if the stack is empty.

Implementing a Stack in C++

In C++, you can use the std::stack container class to implement a stack. The std::stack class is a container adapter that uses a deque or a list as its underlying container.

Here's an example of creating and using a stack in C++:

1#include <iostream>
2#include <stack>
3
4int main() {
5  // Creating a stack
6  std::stack<int> myStack;
7
8  // Pushing elements into the stack
9  myStack.push(1);
10  myStack.push(2);
11  myStack.push(3);
12
13  // Checking if the stack is empty
14  bool empty = myStack.empty();
15
16  // Getting the topmost element
17  int topElement = myStack.top();
18
19  // Popping elements from the stack
20  myStack.pop();
21
22  return 0;
23}

Understanding the stack data structure is important in many areas of computer science and programming. It is commonly used in algorithms and data processing tasks. By mastering the stack, you'll have a powerful tool in your coding toolbox.

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#include <iostream>

#include <stack>

​

int main() {

  // Creating a stack

  std::stack<int> myStack;

​

  // Pushing elements into the stack

  myStack.push(1);

  myStack.push(2);

  myStack.push(3);

​

  // Checking if the stack is empty

  bool empty = myStack.empty();

​

  // Getting the topmost element

  int topElement = myStack.top();

​

  // Popping elements from the stack

  myStack.pop();

​

  return 0;

}