Understanding iterative preorder traversal

To understand the iterative implementation of preorder traversal, we need to split the whole process into small steps and understand how each step functions. Once we get the intuition behind these individual steps, we can connect them to devise an algorithm for iterative preorder traversal. Let us start by looking at how preorder traversal is done.

• Step 1: Visit the node.
• Step 2: Recursively traverse the node's `left` subtree.
• Step 3: Recursively traverse the node's `right` subtree.

Iterative Steps

This traversal is recursive as the second and third steps of preorder traversal use preorder traversal again. Let us look at this traversal's distinct iterative processes and how we can implement these steps. Once we have implemented these individual steps, we can glue them together to create an iterative algorithm for the entire traversal. Preorder traversal can be broken down into two iterative steps :

• Step 1: Visit the node and traverse its `left` subtree.
• Step 2: Traverse the node's `right` subtree.

1. Visit the node and traverse its left subtree.