Identifying the range postorder pattern

The range binary postorder technique can solve some special types of binary search tree problems. These are generally medium problems in which we are given a range and need to process every node in the tree within that range. In most problems, to process a node, we need the aggregated values of some function f over all the nodes in its left and right subtree that also lie within the given range. The technique is a mix of binary search and the postorder technique

If the problem statement or its solution follows the generic template below, it can be solved by applying the range postorder technique.