Stack Implementation using Linked List

Welcome to our deep dive into implementing a Stack using Linked List! This lesson is perfect for beginners and intermediates who want to understand data structures from the ground up. Let's get started!

What is a Stack? 🎯

A Stack is a data structure that follows the Last In, First Out (LIFO) principle. It's like a pile of plates where you can only add or remove plates from the top. In programming, stacks are used for functions calls, undo/redo operations, and more.

Why Linked List for Stack? 💡

Linked List is an ideal choice for a Stack implementation because it allows for dynamic resizing, making it suitable for varying data sizes. Each element in a Linked List consists of data and a reference to the next element, forming a chain-like structure.

Implementing a Stack using Linked List 📝

Let's create a simple Linked List for a Stack.

python

class Node:
    def __init__(self, data=None):
        self.data = data
        self.next = None

class LinkedStack:
    def __init__(self):
        self.top = None

    def push(self, data):
        new_node = Node(data)
        if not self.top:
            self.top = new_node
        else:
            new_node.next = self.top
            self.top = new_node

    def pop(self):
        if not self.top:
            return None
        data = self.top.data
        self.top = self.top.next
        return data

    def peek(self):
        if not self.top:
            return None
        return self.top.data

✅ Here's what you've learned:

Understood the concept of a Stack and its LIFO nature
Realized why Linked List is a good choice for Stack implementation
Implemented a simple Linked List Stack in Python

Practical Application 💡

A Stack can be used to implement browser history or a parser for evaluating arithmetic expressions. Try creating these applications using the Stack implementation we covered!

Quiz Time 📝

Question: Which of the following data structures follows the LIFO principle?

A: Queue B: Stack C: Tree Correct: B Explanation: Stack follows the Last In, First Out (LIFO) principle, while Queue follows the First In, First Out (FIFO) principle.

Happy learning, and see you in the next lesson! 😊