A simple approach to using a binary heap for sorting is to first the list and then to repeatedly pop the item at the root of the heap, adding each item to the end of a list which is then in sorted order. This is not an sort because it requires more memory than just the initial list. Standard heap sort, on the other hand, starts by the list, then the items at either end of the heap. It then repeats this process with the heap part of the data becoming smaller, and the ordered list partition of the data becoming larger until the is empty. Heap sort has complexity and average cases. in the median heapifying best O(n) Odlog n) hash increment dropping in-place On log n) external swapping heapify recursing reverse larger On squared) list heap best, worst worst