Lesson 8: Tree Traversal

Tree traversal is the process of visiting every node in a tree exactly once. Traversal is important when printing, searching, evaluating, or copying tree structures.

For binary trees, the common traversal methods are:

Preorder Traversal

Preorder visits the root before its subtrees.

Root -> Left -> Right

This is useful when copying a tree or displaying a prefix expression.

Inorder Traversal

Inorder visits the left subtree first, then the root, then the right subtree.

Left -> Root -> Right

For a binary search tree, inorder traversal displays values in sorted order.

Postorder Traversal

Postorder visits both subtrees before the root.

Left -> Right -> Root

This is useful when deleting a tree or evaluating postfix expressions.

Level-Order Traversal

Level-order traversal visits nodes from top to bottom, moving left to right at each level. It is commonly implemented using a queue.

---