class PriorityQueue {
            constructor() {
                this.queue = [];
            }
            // enqueue: Push the Value
            enqueue(value, priority) {
                this.queue.push({ value, priority });
                this.queue.sort((a, b) => b.priority - a.priority); //Highest Priority first
            }
            // dequeue: Remove the Value
            dequeue() {
                return this.queue.shift();  // Remove the first item (highest priority)
            }

            peek() {
                return this.queue[0];
            }

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

        // Demo
        const pq = new PriorityQueue();
        pq.enqueue("Fever", 1);
        pq.enqueue("Accident", 5);
        pq.enqueue("Headache", 3);

        console.log(pq.dequeue());  // Accident (priority 5)
        console.log(pq.dequeue());  // Headache (priority 3)
        

    class MaxPriorityQueue {
    constructor() {
        this.heap = [];
    }

    // Enqueue an item
    enqueue(value, priority) {
        this.heap.push({ value, priority });
        this.heapifyUp();
    }

    // Move new node up
    heapifyUp() {
        let index = this.heap.length - 1;
        while (index > 0) {
            let parent = Math.floor((index - 1) / 2);
            if (this.heap[index].priority <= this.heap[parent].priority) break;
            this.swap(index, parent);
            index = parent;
        }
    }

    // Dequeue highest-priority item
    dequeue() {
        if (this.heap.length === 0) return null;
        const max = this.heap[0];
        const end = this.heap.pop();

        if (this.heap.length > 0) {
            this.heap[0] = end;
            this.heapifyDown();
        }
        return max;
    }

    // Restore heap downwards
    heapifyDown() {
        let index = 0;
        let length = this.heap.length;
        while (true) {
            let left = 2 * index + 1;
            let right = 2 * index + 2;
            let largest = index;

            if (left < length && this.heap[left].priority > this.heap[largest].priority) {
                largest = left;
            }

            if (right < length && this.heap[right].priority > this.heap[largest].priority) {
                largest = right;
            }

            if (largest === index) break;
            this.swap(index, largest);
            index = largest;
        }
    }

        // View front item
        front() {
            return this.heap.length > 0 ? this.heap[0] : null;
        }

        size() {
            return this.heap.length;
        }

        // Is Empty?
        isEmpty() {
            return this.heap.length === 0;
        }

        // Swap Helper
        swap(i, j) {
            [this.heap[i], this.heap[j]] = [this.heap[j], this.heap[i]];
        }
}