Eolymp 4036: Pre-Order Traversal of a Tree & 4038: Post-Order Traversal of a Tree

Problem statement These are two identical problems: Eolymp 4036 and 4038. The following problem statement is that of 4038, but explanation covers both problems. Given an array of integers. Create a Binary Search Tree from these numbers. If the inserted value equals to the current node, insert it to the right subtree. Write method PostOrder that makes Post-Order traversal of a tree. In this traversal method the left subtree is visited first, then the right subtree and finally the root node.