Deque

Overview

A deque, short for double-ended queue, is a data structure that allows insertion and deletion at both ends. It combines features of both stacks and queues, providing flexibility in how elements are added and removed.

Double-Ended Operations

Unlike a regular queue that only allows adding at the rear and removing from the front, a deque lets you add or remove from either end. This makes it versatile for problems that need flexibility in element ordering.

Operations on Both Ends

A deque supports four main operations: addFront adds to the front, addRear adds to the rear, removeFront removes from the front, and removeRear removes from the rear. This dual-end access makes deques powerful for various algorithms.

Use Cases

Deques are useful when you need to process elements from both ends, such as in sliding window problems, implementing certain algorithms like palindrome checking, or when you need stack-like and queue-like behavior in the same data structure.

Implementation Flexibility

Deques can be implemented using arrays or linked lists. Array-based implementations can be more memory-efficient, while linked list implementations avoid shifting elements. The choice depends on your specific needs and constraints.