Stacks Introduction

A stack is a linear data structure that follows the Last In, First Out (LIFO) principle. Elements are added (pushed) and removed (popped) from the same end, referred to as the "top" of the stack.

Key Operations

• Push: Add an element to the top of the stack.
• Pop: Remove and return the top element.
• Peek/Top: View the top element without removing it.
• isEmpty: Check if the stack is empty.
• isFull: Check if the stack is full (in fixed-size implementations).

Real-World Example

A stack can be likened to a stack of plates in a cafeteria. You can only add or remove plates from the top. For instance, in a browser, the "back" button uses a stack to store the history of visited pages, allowing you to return to the most recently visited page first.

Why Use Stacks?

Stacks are used in scenarios requiring reversal or backtracking, such as:

• Function call stack in programming (e.g., recursion).
• Undo functionality in text editors.
• Expression evaluation (e.g., parsing mathematical expressions).

Queues Introduction

A queue is a linear data structure that follows the First In, First Out (FIFO) principle. Elements are added at the "rear" and removed from the "front."

Key Operations

• Enqueue: Add an element to the rear of the queue.