Editing Smoothsort (section)

====Optimization====
Dijkstra's algorithm saves work by observing that the full heap invariant is required at the end of the growing phase, but it is not required at every intermediate step.  In particular, the requirement that an element be greater than its stepson is only important for the elements which are the final tree roots.

Therefore, when an element is added, compute the position of its future parent.  If this is within the range of remaining values to be sorted, act as if there is no stepson and only sift down within the current tree.