Method downheap

lectures/24-heaps/code/heaps-1/Heap.java:59–76

(int index)

    return temp;
  }
  private void downheap(int index) {
    int min = index;
    int left = left(index);
    int right = right(index);

    if(left < list.size() && list.get(min).compareTo(list.get(left)) > 0) {
      min = left;
    }

    if(right < list.size() && list.get(min).compareTo(list.get(right)) > 0) {
      min = right;
    }

    if(min != index) {
      swap(min, index);
      downheap(min);
    }
  }

  public ArrayList<T> heapSort() throws Exception {
    ArrayList<T> data = new ArrayList<>();