Implementing a Queue
Explore how to implement a queue data structure in Python through array-based and linked list-based methods. Understand key concepts such as queue operations, memory layout, dynamic resizing, and when to choose each implementation. This lesson helps you build foundational queue skills essential for efficient data handling.
Now that we understand what a queue is, the next step is to examine how it is implemented. A queue is an abstract data structure. It defines a set of behaviors, but it does not dictate how the data must be stored or managed in memory. Just like a stack, a queue can be built on top of different underlying structures, using both an array and a linked list.
Using an array
In an array-based implementation, we use an array, or a dynamic array, to store queue elements, with all elements stored in a contiguous block of memory. The queue elements are placed in the array, and the array indices represent the front and rear of the queue. A size counter tracks the number of elements currently in the queue.
If the array has a fixed size, then the queue has a maximum capacity. If a dynamic array is used, the structure can grow, although some queue designs still manage front and rear positions explicitly.
Here’s what an array-based queue looks like:
As elements are dequeued from the front, the positions they occupied become empty. In a naive ...