in c++

please help me

A queue is a data type with a bounded (predefined) capacity. It is a simple data structure that uses an array and adds elements in one end and removes them from the other end, just like a queue or line at the market checkout. You enter the line at the rear, and after youve paid for your items, you leave at the front. We call this a FIFO (First In First Out) structure. Every time an element is added, it goes in the REAR of the queue, and when an element is removed, all elements before it are also removed (look at the sample run).

you will be implementing a queue using an array data structure.

Task

You are not allowed to use , or any other header files in STL.

Complete the functions enqueue() and dequeue(). The function printQueue()has been created for you. Please use printQueue() to print the queue.

Complete the function: int enqueue(int queue[], int &size, int val)

Inserts a value into the REAR of a queue of integers.

Takes three arguments:

queue The array containing the queue

size A reference to the number of elements in the queue

val The value to insert

Returns 0 on success, 1 on overflow (queue is full, cannot add).

For example, queue with MAX of 5 and size 3, after integers 8, -2, 3 were added in that order (calls to enqueue(queue, size, 8), enqueue(queue, size, -2), enqueue(queue, size, 3)):

Complete the function: int dequeue(int queue[], int &size, int &val)

Removes a value out of a queue of integers.

Integers are removed from the FRONT of the queue.

If the integer is in the queue, ALL integers before are also removed and the remaining elements are shifted to the FRONT of the queue.

The first occurrence is removed if there are multiple occurrences.

Takes three arguments:

queue The array containing the queue

size A reference to the number of elements in the queue

val The integer to be removed from the queue

Returns 0 on success, 1 on underflow (queue is empty, no values to dequeue), 2 if integer is not in the queue.

For example, using the queue above, the queue after a call to dequeue(queue, size, -2), notice both elements 8 and -2 were removed from the queue and 3 was moved to the front of the queue, size is now 1:

Requirements for enqueue()and dequeue() functions:

Do not alter the existing prototypes.

Your functions should insert the integers from the REAR of the queue, low indices to high indices; that is, newer elements should be added at higher array indices. FRONT of the queue is at index 0.

If an overflow or an underflow occurs, your functions must return an error code; they should not attempt to modify the queue. Handle the return code in the main() function, print the error message in main().

enqueue and dequeue should only manipulate the given queue; they should not print anything!

In your main(), an array of size 3 has been declared for you. Using a small array will make it easier to debug all of the conditions. You should then read user commands (input type char) and use the queue functions to manipulate the queue accordingly. The program must support the following single-character commands:

+ Adds an integer into the rear of the queue.

- Removes an integer from the front of the queue. All integers before are also removed (see sample run).

p Prints the queue.

q Quit.

The queue should be printed using printQueue() after every command except q.

If an unknown command is entered, print an error message and DO NOT print the queue.

Use only the concepts we have learned so far.

Please follow ALL the instructions to submit your file in the Criteria for Success section below.

Criteria for Success

Test your program using the following sample runs using the given queue size of 3, making sure you get the same output using the given inputs (in blue).

+ 9 + 3 + -2 + 10 - 5 - 3 @ p - -2 - 0 + 23 q

Welcome to the FIFO Queue Program!

Enter option: +

Integer: 9

[9]

Enter option: +

Integer: 3

[9, 3]

Enter option: +

Integer: -2

[9, 3, -2]

Enter option: +

Integer: 10

Error: Queue Overflow!

[9, 3, -2]

Enter option: -

Integer: 5

5 is not in the queue.

[9, 3, -2]

Enter option: -

Integer: 3

[-2]

Enter option: @

Invalid option.

Enter option: p

[-2]

Enter option: -

Integer: -2

[]

Enter option: -

Integer: 0

Queue Empty.

[]

Enter option: +

Integer: 23

[23]

Enter option: q

Goodbye!