Simple Queue Implementation in c++

queue.cpp

#include <iostream>
using namespace std;
#define null 0

class QueueArray {
private:
    int front;
    int rear;
    int numOfEl;
    int size;
    int *queueArr;
    void resize() {
        int tempSize = size * 2;
        int *tempArr = new int[tempSize];
        for(int i = 0; i < size; i++) tempArr[i] = queueArr[(front + i) % size];
        delete[] queueArr;
        queueArr = tempArr;
        front = 0;
        rear = size - 1;
        size = tempSize;
    }
public:
    QueueArray(int size) {
        front = rear = -1;
        this->size = size;
        queueArr = new int[size];
        numOfEl = 0;
    }
    void Enqueue(int data) {
        if(numOfEl == size) resize();
        if(front == -1 && rear == -1) front = rear = 0;
        else rear = (rear + 1) % size;
        queueArr[rear] = data;
        numOfEl++;
    }
    void Dequeue() {
        if(numOfEl != 0) {
            if(front == rear) rear = front = -1;
            else front = (front + 1) % size;
            numOfEl--;
        }
    }
    void print() {
        int count = (rear + size - front) % size + 1;
        for(int i = 0; i < count; i++) {
            cout << queueArr[(front + i) % size] << endl;
        }
        cout << endl;
    }
    void test() {
        Enqueue(4);
        Enqueue(2);
        Enqueue(7);
        Enqueue(8);
        print();
        Dequeue();
        Dequeue();
        print();
    }
    ~QueueArray() {
        delete[] queueArr;
    }
};

class Node {
public:
    int data;
    Node *next;
    Node(int data) {
        this->data = data;
        next = null;
    }
};

class QueueLinkedList {
private:
    Node *front;
    Node *rear;
public:
    QueueLinkedList() {
        front = rear = null;
    }
    void Enqueue(int data) {
        Node *n = new Node(data);
        if(rear == null) rear = front = n;
        else {
            rear->next = n;
            rear = n;
        }
    }
    void Dequeue() {
        if(front != null) {
            Node *temp = front;
            if(front == rear) front = rear = null;
            else front = front->next;
            delete(temp);
        }
    }
    void print() {
        Node *temp = front;
        while(temp != null) {
            cout << temp->data << endl;
            temp = temp->next;
        }
        cout << endl;
    }
    void test() {
        Enqueue(666);
        Enqueue(7);
        Enqueue(21);
        print();
        Dequeue();
        Dequeue();
        print();
    }
    ~QueueLinkedList() {
        Node *next;
        while(front != null) {
            next = front->next;
            delete front;
            front = next;
        }
        front = null;
        rear = null;
    }
};

int main() {
    cout << endl << "Array:" << endl;
    QueueArray qa(4);
    qa.test();
    cout << endl << "Linked List:" << endl;
    QueueLinkedList qll;
    qll.test();
    return 0;
}