Javascript Algorithm Array Sort Heap sort

function heapSort(list) {
  // left child//from  w w w  .ja v  a 2 s .c  o m
  function left(p) {
    return 2 * p + 1;
  }
  // right child
  function right(p) {
    return 2 * p + 2;
  }
  // parent node
  function parent(c) {
    return Math.floor((c - 1) / 2);
  }
  // restore heapproperty assuming that child trees of x are max-heaps
  function heapify(list, x, size) {
    var largest = x, tmp;
    while (x >= 0) {
      if (right(x) < size && list[right(x)] > list[largest]) {
        largest = right(x);
      }
      if (left(x) < size && list[left(x)] > list[largest]) {
        largest = left(x);
      }
      if (largest == x) {
        break;
      }
      tmp = list[largest];
      list[largest] = list[x];
      list[x] = tmp;
      x = largest;
    }
  }

  // variable declarations
  var i, tmp, size;

  // create heap datastructure
  for (var i = parent(list.length - 1); i >= 0; i--) {
    heapify(list, i, list.length);
  }

  // sort the values by pulling out max value from the top of heap
  size = list.length;
  while (size > 0) {
    // swap
    tmp = list[0];
    list[0] = list[size - 1];
    list[size - 1] = tmp;
    heapify(list, 0, size - 1);
    size--;
  }
  return list;
}

console.log(heapSort([ 23, 45, 2, 57, 24, 68, 6, 8, 27, 2, 1, 8, 9, 4, 7,
    0, 34, 56, 78, 7, 34, 67, 34, 37, 14, 53, 68, 374, 65, 3 ]));