class PriorityQueue {
    constructor() {
        this.items = [];
    };

    enqueue(item, priority) {
        const element = { item, priority };
        let added = false;

        for (let i = 0; i < this.items.length; i++) {
            if (priority < this.items[i].priority) {
                this.items.splice(i, 0, element);
                added = true;
                break;
            };
        };

        if (!added) this.items.push(element);
    }

    dequeue() {
        return this.isEmpty() ? null : this.items.shift().item;
    }

    isEmpty() {
        return this.items.length === 0;
    }
};

module.exports = PriorityQueue;