class CircularQueue {
    constructor(size) {
        this.element = [];
        this.size = size 
        this.length = 0 
        this.front = 0 
        this.back = -1
    }
    isEmpty() {
        return (this.length == 0)
    }
    enqueue(element) {
        if (this.length >= this.size) 
            throw (new Error("Maximum length exceeded")) 
        this.back++
        this.element[this.back % this.size] = element 
        this.length++
    }
    dequeue() {
        if (this.isEmpty())
                throw (new Error("No elements in the queue"))
        const value = this.getFront()
        this.element[this.front % this.size] = null 
        this.front++
        this.length--
        return value
    }
    getFront() {
        if (this.isEmpty()) 
            throw (new Error("No elements in the queue")) 
        return this.element[this.front % this.size]
    }
    clear() {
        this.element = new Array();
        this.length = 0 
        this.back = 0 
        this.front = -1
    }
}