Tree Traversal Methods

Tree traversal is a key part of working with tree data structures, especially binary trees. There are three main ways to traverse, or visit, the nodes in these trees:

1. Preorder Traversal:

   • You start by visiting the main node, then you go to the left side, and finally the right side.
   • The order is: Root, Left, Right.
   • It takes time based on how many nodes are in the tree, which is called $O(n)$.

2. Inorder Traversal:

   • Here, you visit the left side first, then the main node, and then the right side.
   • The order is: Left, Root, Right.
   • This method is often used in binary search trees to get the nodes in order, which makes them sorted.
   • It also takes time based on the number of nodes, or $O(n)$.

3. Postorder Traversal:

   • First, visit the left side, then the right side, and lastly the main node.
   • The order is: Left, Right, Root.
   • This method is helpful for removing trees or carrying out tasks like finding the height of the tree.
   • It also takes $O(n)$ time to complete.

Understanding these methods helps us work better with tree structures in programming!