heapin it on

heaps.js

var heap = {
  heap: [],
  add(n) {
    this.heap.push(n)
    this.siftUp()
  },
  pop() {
    let res = this.heap[0]
    this.heap[0] = this.heap[this.heap.length - 1]
    this.heap.pop()
    this.siftDown()
    return res
  },
  siftDown() {
    let curr = 0
    let top = this.heap[curr]
    let leftIdx = curr * 2 + 1
    let rightIdx = leftIdx + 1
    while (leftIdx < this.heap.length) {
      if (rightIdx < this.heap.length) {
        if (this.heap[leftIdx] < this.heap[rightIdx]) {
          if (this.heap[leftIdx] < this.heap[curr]) {
            this.heap[curr] = this.heap[leftIdx]
            this.heap[leftIdx] = top
            curr = leftIdx
          } else {
            break
          }
        } else {
          if (this.heap[rightIdx] < this.heap[curr]) {
            this.heap[curr] = this.heap[rightIdx]
            this.heap[rightIdx] = top
            curr = rightIdx
          } else {
            break
          }
        }
      } else {
        if (this.heap[leftIdx] < this.heap[curr]) {
          this.heap[curr] = this.heap[leftIdx]
          this.heap[leftIdx] = top
          curr = leftIdx
        } else {
          break
        }
      }
      leftIdx = curr * 2 + 1
      rightIdx = leftIdx + 1
    }
  },
  siftUp() {
    let curr = this.heap.length - 1
    let bot = this.heap[curr]
    let next = Math.ceil((curr - 2) / 2)
    while (next >= 0 && this.heap[next] > this.heap[curr]) {
      this.heap[curr] = this.heap[next]
      this.heap[next] = bot
      curr = next
      next = Math.ceil((curr - 2) / 2)
    }
  }
}


for (var i = 0; i < 100; i++) {
  heap.add(Math.ceil(Math.random() * 100))
}
while(heap.heap.length) {
  console.log(heap.pop())
}