Explain how a queue can be implemented using an array, where the enqueue and the dequeue operations are both constant time operations (for simplicity, assume that you will never need to expand the capacity of the array).

Question

What will be an ideal response?

Answer 1

In order to implement a queue as an array where both the enqueue and the dequeue operations require a
constant amount of time, the queue must be implemented as a circular array, meaning that the end of the array and the
beginning of the array is connected. We can use the remainder (%) operator to simulate an array with this property. In this
setting, the front of the queue and the back of the queue can always be at different indexes, and if we need to enqueue an
element when the end of the queue is located at the last index of the array, we enqueue it as the first element in the array. This
allows the enqueue and the dequeue operations to be implemented in constant time.