A program stores positive integers in a circular queue. The queue is stored as a global 1D array of 20 integers with the identifier Queue. Each index is initialised with the data -1 The global variable HeadPointer, initialised to -1, points to the first element in the queue. The global variable TailPointer, initialised to −1, points to the last element in the queue. The global variable NumberItems, initialised to 0, stores the number of items in the queue.

1. (a)Write program code to declare and initialise Queue, HeadPointer, TailPointer and NumberItems[2]
2. (b)The function Enqueue(): • takes an integer as a parameter • checks if the queue is full • returns FALSE if the queue is full • stores the parameter in the next position in the queue and returns TRUE if the queue is not full • updates the appropriate pointers and NumberItems Write program code for Enqueue()[6]
3. (c)The main program: • attempts to store each of the integers 1 to 25 (inclusive) in the queue in ascending numerical order using Enqueue() • outputs the integer that was passed to Enqueue() and "Successful" if it was stored in the queue, or "Unsuccessful" if it was not stored in the queue. For example: Ο if the integer 5 is passed to Enqueue() and is stored in the queue, the output will be: "5 Successful" Ο if the integer 23 is passed to Enqueue() and is not stored in the queue, the output will be: "23 Unsuccessful" Write program code for the main program.[3]
4. (d)The function Dequeue() returns -1 if the queue is empty. If the queue is not empty, the function returns the next item in the queue, updates the appropriate pointers and updates NumberItems Write program code for Dequeue()[6]
5. (e)(i)Write program code to extend the main program to call Dequeue() twice and output the return value each time.[2]
6. (e)(ii)Test your program. Take a screenshot of the output(s). Copy and paste the screenshot into part 1(e)(ii) in the evidence document.[1]