In a binary tree, which traversal method accesses the nodes in left-root-right order?

In a binary tree, the traversal method that accesses the nodes in left-root-right order is known as in-order traversal. This technique involves first visiting the left subtree, then the root node, and finally the right subtree. This order is particularly significant when dealing with binary search trees (BSTs), as an in-order traversal will yield the nodes in sorted order.

To visualize this, consider a simple binary tree structure where you start at the root. In in-order traversal, you would go as far left as you can, accessing the leftmost node first, then processing the node (the root of the current subtree), and finally moving to the right child. This method clearly delineates how the nodes are engaged in a sequence that respects both the hierarchical structure of the tree and the relative positioning of the elements, which is crucial for operations that require sorted data retrieval.

The other traversal methods, such as pre-order (root-left-right), post-order (left-right-root), and level-order (explores each level of the tree from top to bottom and left to right) do not follow the left-root-right sequence that defines in-order traversal.