queue using array

#include <iostream>
using namespace std;

class Queue {
    int arr[10];
    int front, rear;
public:
    Queue() { front = rear = -1; }

    void enqueue(int val) {
        if (rear == 9)
            cout << "Queue Overflow!\n";
        else {
            if (front == -1) front = 0;
            arr[++rear] = val;
            cout << val << " enqueued.\n";
        }
    }

    void dequeue() {
        if (front == -1 || front > rear)
            cout << "Queue Underflow!\n";
        else
            cout << arr[front++] << " dequeued.\n";
    }

    void display() {
        cout << "Queue: ";
        for (int i = front; i <= rear && i >= 0; i++)
            cout << arr[i] << " ";
        cout << endl;
    }
};

int main() {
    Queue q;
    q.enqueue(10);
    q.enqueue(20);
    q.display();
    q.dequeue();
    q.display();

    cout << "\nTime Complexity: O(1)\nSpace Complexity: O(n)\n";
    return 0;
}