A linear queue data structure is designed using a record structure. The record structure Queue has the following fields: • QueueArray, a 1D array of up to 100 integer values • Headpointer, a variable that stores the index of the first data item in QueueArray • Tailpointer, a variable that stores the index of the next free location in QueueArray.

1. (a)Write program code to declare the record structure Queue and its fields. If your programming language does not support record structures, a class can be declared instead. If you are writing in Python, use comments to declare the appropriate data types. Save your program as Question2_N24. Copy and paste the program code into part 2(a) in the evidence document.[3]
2. (b)The main program creates a new Queue record with the identifier TheQueue. The head pointer is initialised to −1. The tail pointer is initialised to 0. Each element in the array is initialised with -1. Write program code for the main program. Save your program. Copy and paste the program code into part 2(b) in the evidence document.[3]
3. (c)The pseudocode function Enqueue() inserts an integer value into the queue. The function is incomplete. There are three incomplete statements. FUNCTION Enqueue(BYREF AQueue : Queue, BYVAL TheData : INTEGER) RETURNS INTEGER IF AQueue.Headpointer = -1 THEN AQueue.QueueArray[AQueue.Tailpointer] ← .......... AQueue.Headpointer ← 0 AQueue.Tailpointer ← AQueue.Tailpointer + 1 RETURN 1 ELSE IF AQueue.Tailpointer > .......... THEN RETURN -1 ELSE AQueue.QueueArray[AQueue.Tailpointer] ← TheData AQueue.Tailpointer ← AQueue.Tailpointer + 1 RETURN 1 ENDIF ENDIF ENDFUNCTION Write program code for Enqueue(). Save your program. Copy and paste the program code into part 2(c) in the evidence document.[5]
4. (d)The function ReturnAllData() accesses TheQueue. It concatenates all the integer values that have been inserted into the queue's array, starting from the value stored at HeadPointer, with a space between each integer value. The string of concatenated values is returned. None of the integer values are removed from the queue. Write program code for ReturnAllData(). Save your program. Copy and paste the program code into part 2(d) in the evidence document.[3]
5. (e)(i)The main program asks the user to enter 10 integers with values of 0 or greater. It reads each input repeatedly until a valid number is entered. All 10 valid inputs are added to the queue, using Enqueue(). If the value returned from Enqueue() is −1, a message is output to state that the queue is full, otherwise a message is output to state that the item has been added to the queue. The function ReturnAllData() is called once all 10 integers have been entered and the return value from the function call is output. Amend the main program to perform these actions. Save your program. Copy and paste the program code into part 2(e)(i) in the evidence document.[5]
6. (e)(ii)Test your program with the following inputs in the order given: 10 9 -1 8 7 6 5 4 3 2 1 Take a screenshot of the output. Save your program. Copy and paste the screenshot into part 2(e)(ii) in the evidence document.[2]
7. (f)The function Dequeue() accesses TheQueue. The function returns –1 if the queue is empty. If the queue is not empty, the function returns the next item in the queue and updates the relevant pointer(s). The data is not replaced or deleted from the queue. Write program code for Dequeue(). Save your program. Copy and paste the program code into part 2(f) in the evidence document.[4]
8. (g)(i)The main program calls Dequeue() twice, and each time it either outputs 'Queue empty' if there is no data in the queue or outputs the return value. The main program then calls ReturnAllData() a second time. Amend the main program. Save your program. Copy and paste the program code into part 2(g)(i) in the evidence document.[3]
9. (g)(ii)Test your program with the following inputs in the order given: 10 9 8 7 6 5 4 3 2 1 Take a screenshot of the output. Save your program. Copy and paste the screenshot into part 2(g)(ii) in the evidence document.[1]