Postorder Traversal is a tree traversal method where the nodes are visited in the following order: Left subtree, Right subtree, then the Root. This is particularly useful in scenarios where you need to visit child nodes before their parent, such as in expression tree evaluations or memory deallocations.
Algorithm:
- Traverse the left subtree.
- Traverse the right subtree.
- Visit the root node.
Example for a binary tree:
Postorder: D, E, B, C, A.
In code, recursion is typically used: