How do Stacks and Queues differ from each Other

Stacks and queues are both abstract data types used to store and manage elements, but they differ in their principles of operation and the order in which elements are accessed or removed:

 

Stack:

1. Principle of Operation: Follows the Last In, First Out (LIFO) principle, meaning that the last element added to the stack is the first one to be removed.

2. Insertion and Removal: Elements are added and removed from the same end of the stack, known as the top or the head.

3. Operations:

   • Push: Adds an element to the top of the stack.
   • Pop: Removes and returns the top element from the stack.
   • Peek (Top): Returns the top element of the stack without removing it.

4. Usage: Stacks are used in scenarios where the order of processing is important, such as function calls (call stack), expression evaluation, undo mechanisms, and backtracking algorithms.

 

Queue:

1. Principle of Operation: Follows the First In, First Out (FIFO) principle, meaning that the first element added to the queue is the first one to be removed.

2. Insertion and Removal: Elements are added at the rear or tail of the queue and removed from the front or head.

3. Operations:

   • Enqueue: Adds an element to the rear of the queue.
   • Dequeue: Removes and returns the front element from the queue.
   • Front and Rear: Operations to access the front and rear elements of the queue without removing them.

4. Usage: Queues are used in scenarios where tasks or processes need to be executed in the order they were received, such as task scheduling, job queues, printer queues, and breadth-first search algorithms.

 

In summary, stacks and queues differ in their order of operations (LIFO vs. FIFO) and the ends from which elements are added and removed. Stacks are suitable for scenarios where the last element added should be processed first, while queues are suitable for scenarios where the first element added should be processed first. Both data structures have their own applications and are fundamental in computer science and software engineering.

 

Thank you,