Implement a PostOrder traversal of a tree. In this traversal the left subtree is visited first, then the the right subtree and finally the root node.
Definition of a tree:
Implement function PostOrder that prints in one line the vertices of the tree in order of PostOrder traversal. Separate the vertices with one space.
During the PostOrder traversal vertices will be printed in the next order: 1 3 2 9 16 10 4.