Study the "Queue as linked list simple example" posted in this module. Rewrite the code to use array instead of linked lists. Please do not change anything besides the data structure. Instead of linked list use an array. The functionality should remain exactly the same.

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/** * Queue implementation using linked list C style implementation ( no OOP). */

#include #include #include #include

#define CAPACITY 100 // Queue max capacity

using namespace std; /** Queue structure definition */ struct QueueType { int data; struct QueueType * next; }; /** Queue size */ unsigned int size = 0;

int enqueue(QueueType * &rear, QueueType * &front, int data); int dequeue(QueueType * &front); int getRear(QueueType * &rear); int getFront(QueueType * &front); void display(QueueType * front); int isEmpty(); int isFull(); string prepMenu();

int main() { int option, data;

QueueType *rear, *front;

rear = NULL; front = NULL; string menu = prepMenu(); cout << menu << endl; cin >> option; while (option !=7) {

switch (option) { case 1: cout << " Enter data to enqueue (-99 to stop): "; cin >> data; while ( data != -99) { /// Enqueue function returns 1 on success /// otherwise 0 if (enqueue(rear, front, data)) cout << "Element added to queue."; else cout << "Queue is full." << endl; cout << " Enter data to enqueue (-99 to stop): "; cin >> data; }

break;

case 2: data = dequeue(front);

/// on success dequeue returns element removed /// otherwise returns INT_MIN if (data == INT_MIN) cout << "Queue is empty."<< endl; else cout << "Data => " << data << endl;

break;

case 3:

/// isEmpty() function returns 1 if queue is emtpy /// otherwise returns 0 if (isEmpty()) cout << "Queue is empty."<< endl; else cout << "Queue size => "<< size << endl;

break;

case 4: data = getRear(rear);

if (data == INT_MIN) cout << "Queue is empty." << endl; else cout << "Rear => " << data << endl;

break;

case 5:

data = getFront(front);

if (data == INT_MIN) cout <<"Queue is empty."<< endl; else cout <<"Front => " << data << endl;

break;

case 6: display(front); break;

default: cout <<"Invalid choice, please input number between (0-5). "; break; }

cout <<" "; cout << menu<< endl; cin >> option; } }

/** * Enqueues/Insert an element at the rear of a queue. * Function returns 1 on success otherwise returns 0. */ int enqueue(QueueType * &rear, QueueType * &front, int data) { QueueType * newNode = NULL;

/// Check queue out of capacity error if (isFull()) { return 0; }

/// Create a new node of queue type newNode = new QueueType;

/// Assign data to new node newNode->data = data;

/// Initially new node does not point anything newNode->next = NULL;

/// Link new node with existing last node if ( (rear) ) { rear->next = newNode; }

/// Make sure newly created node is at rear rear = newNode;

/// Link first node to front if its NULL if ( !( front) ) { front = rear; }

/// Increment quque size size++;

return 1; }

/** * Dequeues/Removes an element from front of the queue. * It returns the element on success otherwise returns * INT_MIN as error code. */ int dequeue(QueueType * &front) { QueueType *toDequque = NULL; int data = INT_MIN;

// Queue empty error if (isEmpty()) { return INT_MIN; }

/// Get element and data to dequeue toDequque = front; data = toDequque->data;

/// Move front ahead front = (front)->next;

/// Decrement size size--;

/// Clear dequeued element from memory free(toDequque);

return data; }

/** * Gets, element at rear of the queue. It returns the element * at rear of the queue on success otherwise return INT_MIN as * error code. */ int getRear(QueueType * & rear) { // Return INT_MIN if queue is empty otherwise rear. return (isEmpty()) ? INT_MIN : rear->data; }

/** * Gets, element at front of the queue. It returns the element * at front of the queue on success otherwise return INT_MIN as * error code. */ int getFront(QueueType * &front) { // Return INT_MIN if queue is empty otherwise front. return (isEmpty()) ? INT_MIN : front->data; }

/** * Checks, if queue is empty or not. */ int isEmpty() { return (size <= 0); }

/** * Checks, if queue is within the maximum queue capacity. */ int isFull() { return (size > CAPACITY); } string prepMenu() {

string menu = "";

menu+= " ------------------------------------------------------------------- "; menu+= "1.Enqueue 2.Dequeue 3.Size 4.Get Rear 5.Get Front 6.Display 7.Exit "; menu+= "---------------------------------------------------------------------- "; menu+= "Select an option: "; return menu; } void display(QueueType * front) { for ( QueueType *t = front; t !=NULL; t = t->next) cout <data << " "; cout << endl << endl; }