[Blog 010] Data Structures: Stack

A stack is a linear data structure that follows the principle of Last In First Out (LIFO), where the last item added to the stack is the first item to be removed. In this blog post, we will explore the stack data structure, understand its basic operations and implement it using an array in various programming languages.

Let's take an example to understand how a stack works in real-life. Imagine a pile of plates, where you can only add a plate to the top of the pile and the only plate you can remove is the one on the top. This is similar to how a stack works in computer science.

In programming, stacks are widely used in various algorithms such as recursion, parsing expressions, and maintaining the function call stack. Here are some common operations performed on a stack:

1. Push: This operation adds an element to the top of the stack.

2. Pop: This operation removes the top element from the stack.

3. Peek: This operation returns the element at the top of the stack without removing it.

4. isEmpty: This operation returns true if the stack is empty, otherwise false.

Here is an example implementation of a stack in Python:

python code
class Stack:
    def __init__(self):
        self.stack = []

    def push(self, item):
        self.stack.append(item)

    def pop(self):
        return self.stack.pop()

    def peek(self):
        return self.stack[-1]

    def is_empty(self):
        return len(self.stack) == 0

In conclusion, the stack data structure is a fundamental concept in computer science and understanding it is crucial for solving various programming problems. With the help of this blog post, you now have a basic understanding of stacks, their operations, and an example implementation in Python.