What Is Deque How It Is Represented in Memory in Data Structure?

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Scott Campbell

What Is Deque How It Is Represented in Memory in Data Structure?

A deque, short for double-ended queue, is a data structure that allows insertion and removal of elements from both ends. It is similar to a queue and a stack but with more flexibility. In this article, we will explore how a deque is represented in memory.

Deque Overview

A deque can be visualized as a sequence of elements, where each element has two pointers – one pointing to the previous element and one pointing to the next element. This allows for efficient insertion and removal operations at both ends of the deque.

Representation in Memory

In memory, a deque can be implemented using doubly linked list or circular array. Let’s discuss both representations:

In the doubly linked list representation, each node contains three fields:

• Data: The actual value stored in the node.
• Previous: A pointer to the previous node.
• Next: A pointer to the next node.

The first node of the deque is called the head, which points to the first element. Similarly, the last node is called the tail, which points to the last element. Insertion and removal operations at both ends can be performed by updating these pointers accordingly.

Circular Array

In the circular array representation, elements are stored in an array with two indices – front and rear. The front index represents the front element of the deque, while the rear index represents one position after the last element of the deque.

The deque is considered empty when the front and rear indices are equal. To insert an element at the front, we decrement the front index, and to insert an element at the rear, we increment the rear index. Similarly, to remove an element from the front, we increment the front index, and to remove an element from the rear, we decrement the rear index.

Benefits of Deque

• Efficient Insertion and Removal: Deque allows insertion and removal at both ends in constant time complexity.
• Versatility: It can be used as both a queue and a stack, depending on how elements are inserted or removed.
• Flexibility: Deque can be resized dynamically without much overhead.

Conclusion

A deque is a versatile data structure that allows efficient insertion and removal at both ends. It can be represented in memory using a doubly linked list or a circular array. Understanding how a deque is represented enables us to utilize its benefits effectively in various scenarios.

Now that you have learned about deques and their memory representation, you can confidently incorporate them into your future programming projects!