Identifying the Traversal Pattern

The pattern you're seeing is indicative of a tree traversal algorithm. Specifically, what we're doing can be modeled as a Preorder Traversal.

Why Preorder Traversal?

In preorder traversal, we visit the root first, then traverse the left subtree, and finally the right subtree. This is exactly what we're doing while merging the trees:

1. Visit the Root: Merge the root nodes of both trees.
2. Traverse the Left Subtree: Merge the left subtrees of both trees.
3. Traverse the Right Subtree: Merge the right subtrees of both trees.

Here’s how the Preorder Traversal skeleton code might look in JavaScript:

1function preOrder(node) {
2  if (!node) return;
3  // Perform some operation on the current node (like merging)
4  preOrder(node.left);  // Traverse the left subtree
5  preOrder(node.right); // Traverse the right subtree
6}

Adaptation for Merging

To adapt this for merging, we would:

1. Sum the current nodes from both trees and create a new node in the merged tree.
2. Recursively perform this operation for left and right children.

The skeleton code for Preorder Traversal gives us a good framework to build upon for our merging function.