 More specifically if all the subtrees starting at some height formula_1 have already been “heapified” (the bottommost level corresponding to formula_2), the trees at height formula_3 can be heapified by sending their root down along the path of maximum valued children when building a max-heap, or minimum valued children when building a min-heap.This process takes formula_4 operations (swaps) per node.In this method most of the heapification takes place in the lower levels.