Suppose that a queue is implemented using a circular array of size 12. What is the value of last after the following operations? 10 enqueue operations
5 dequeue operations
6 enqueue operations
10 dequeue operations
8 enqueue operations
2 dequeue operations
3 enqueue operations
Last = 10

10

Explanation:

An enqueue operation is a function that adds an element(value) to a queue array. A dequeue operations removes an element from a queue array. Queue arrays follow a first-in-first-out approach, so elements that are first stored in the queue are removed/accessed first(enqueue operations add elements at the rear of the queue array).

The following operations leave 10 elements in the queue of array size 12 after its done:

10 enqueue operations= adds 10 elements

5 dequeue operations= removes 5 elements( 5 elements left in queue)

6 enqueue operations= adds 6 elements(11 elements in queue)

10 dequeue operations= removes 10 elements(1 element left in queue)

8 enqueue operations= adds 8 elements(9 elements in queue)

2 dequeue operations= removes 2 elements(7 elements left in queue)

3 enqueue operations= adds 3 elements(10 elements in queue)

Therefore there are 10 elements in the queue after enqueue and dequeue operations.