Tree traversal

Depth-first search of binary tree

Pre-order (NLR)

For Preorder, you traverse from the root to the left subtree then to the right subtree.

Preorder => Root, Left, Right.

In-order (LNR)

For Inorder, you traverse from the left subtree to the root then to the right subtree.

Inorder => Left, Root, Right.

Reverse in-order (RNL)

Post-order (LRN)

For Post order, you traverse from the left subtree to the right subtree then to the root.

Post order => Left, Right, Root.

Breadth-first search