class BinaryHeap {

constructor() {

this.heap = [];

}

insert(value) {

this.heap.push(value);

this.heapify();

}

size() {

return this.heap.length;

}

empty() {

return this.size() === 0;

}

heapify() {

let index = this.size() - 1;

while (index > 0) {

const element = this.heap[index];

const parentIndex = Math.floor((index - 1) / 2);

const parent = this.heap[parentIndex];

if (parent[0] >= element[0]) break;

this.heap[index] = parent;

this.heap[parentIndex] = element;

index = parentIndex;

}

}

extractMax() {

const max = this.heap[0];

const tmp = this.heap.pop();

if (!this.empty()) {

this.heap[0] = tmp;

this.sinkDown(0);

}

return max;

}

sinkDown(index) {

const left = 2 * index + 1;

const right = 2 * index + 2;

let largest = index;

const length = this.size();

if (left < length && this.heap[left][0] > this.heap[largest][0]) {

largest = left;

}

if (right < length && this.heap[right][0] > this.heap[largest][0]) {

largest = right;

}

// swap

if (largest !== index) {

const tmp = this.heap[largest];

this.heap[largest] = this.heap[index];

this.heap[index] = tmp;

this.sinkDown(largest);

}

}

}

const maxHeap = new BinaryHeap();

maxHeap.insert([4]);

maxHeap.insert([3]);

maxHeap.insert([6]);

maxHeap.insert([1]);

maxHeap.insert([8]);

maxHeap.insert([2]);

while (!maxHeap.empty()) {

const mx = maxHeap.extractMax();

console.log(mx);

}