#include <iostream>

class queue
{
    public:
            queue();     // constructor
            ~queue() {delete [] QArray;}     // destructor deletes the array
            void Enqueue(int X);
            void Dequeue();
            int GetFront();

            // IsEmpty() tests to see if the size of the queue equals zero
            // and returns either true or false
            int IsEmpty() {return Currentsize == 0;}

            // Is Full() tests to see if the number of element in the queue equals
            // the size of the array QArray and returns either true or false
            int IsFull(){return Currentsize == Maxsize;}

            void MakeEmpty();

    private:
            int Maxsize;         // the size of the QArray
            int Currentsize;    // variable to hold the size of the queue at any one time
            int Front;             // index to indicate the position of the Front of the queue
            int Back;             // index to indicate the position of the Back of the queue
            int *QArray;         // QArray is a pointer to an integer
};

// constructor initialises the private members of queue
queue::queue()
{
    Maxsize = 5;
    Currentsize = 0;
    Front = 0; Back = -1; // the back element is initialised to be off the end of the queue
    QArray = new int[Maxsize]; // dynamically allocate the array with new and set its size to Maxsize.
}

// Enqueue() adds elements to the back of the queue
void queue::Enqueue(int X)
{
    if(!IsFull()){
        QArray[++Back] = X;     // increment Back and place element X at position Back in the array
        Currentsize++;             // increment the size of the queue by 1.
        }

else
        cout<<"No room on queue\n";
}
 

// Dequeue() removes and element from the front of the queue
void queue::Dequeue()
{

    if(IsEmpty())
        cout<<"queue empty, nothing to enqueue\n";
    else
        {
            Currentsize--;         // decrement the size of the queue by 1
            Front++;                // increment Front
        }
}

// GetFront returns the element at the front of the queue
int queue::GetFront()
{
    if(!IsEmpty())
        return QArray[Front];
}

// MakeEmpty() sets the size of the queue to zero and reinitialises
// Front and Back to an emtpy queue

void queue::MakeEmpty()
{
    Currentsize =0;
    Front = 0;
    Back = -1;
}