Method upheap

lectures/24-heaps/code/heaps-1/Heap.java:33–42

(int index)

    upheap(list.size() - 1);
  }
  private void upheap(int index) {
    if(index == 0) {
      return;
    }
    int p = parent(index);
    if(list.get(index).compareTo(list.get(p)) < 0) {
      swap(index, p);
      upheap(p);
    }
  }

  public T remove() throws Exception {
    if (list.isEmpty()) {