Queues

18CS32 - DATA STRUCTURES AND APPLICATIONS | Module-2 VTU Notes

VTU | 18CS32 | Module - 2

Queues, Circular Queues, Priority Queues, and Multiple Stacks/Queues

This summary provides an overview of the core concepts related to queues, circular queues, priority queues, multiple stacks and queues, and their applications, as covered in the "Data Structures and Applications" course.

Queues: Definition and Operations:

A queue is a linear data structure that follows the First-In-First-Out (FIFO) principle. Elements are added at the rear (enqueue) and removed from the front (dequeue). Important queue operations include:

- Enqueue: Adding an element to the rear of the queue.

- Dequeue: Removing and returning the front element.

- Front: Viewing the front element without removing it.

- Rear: Viewing the rear element without removing it.

- IsEmpty: Checking if the queue is empty.

- IsFull: Checking if the queue is full.

Array Representation of Queues:

Queues can be implemented using arrays. Proper management of front and rear pointers is necessary to ensure accurate queue operations.

Circular Queues:

Circular queues are a variant where the rear and front pointers wrap around the array, preventing space wastage.

Circular Queues using Dynamic Arrays:

Using dynamic arrays allows circular queues to resize as needed, accommodating varying amounts of data.

Dequeues (Double-Ended Queues):

Dequeues allow insertion and deletion at both ends. They can function as both queues and stacks, offering flexibility in data manipulation.

Priority Queues:

Priority queues store elements with associated priorities. Elements with higher priorities are removed first.

A Mazing Problem:

A maze-solving problem illustrates how queues can be used to find a path from the entrance to the exit of a maze.

Multiple Stacks and Queues:

Implementing multiple stacks or queues within a single array demonstrates space optimization and efficient utilization.

Programming Examples:

Practical programming examples further solidify understanding. These examples involve implementing and manipulating queues, circular queues, and priority queues to solve real-world problems.

Conclusion:

Queues play a vital role in various applications, from managing processes to handling tasks in a systematic order. Circular queues provide optimized space utilization, while priority queues offer efficient sorting. Multiple stacks and queues within a single array showcase innovative memory management. Through programming examples, students gain hands-on experience in applying these concepts. This foundational knowledge equips students for more advanced studies in data structures and their applications in the realm of computer science and software development.