**Search in Binary Search Tree** L:

- Compare X to the
*root*(i.e.*middle value*) (M) in L. - if X = M we are done.
- if X < M we recursively search for X in L's
*left subtree*. - if X > M we recursively search for X in L's
*right subtree*.

**Example:** search for 5 in earlier tree.

It is easy to traverse a BST in increasing order. From the node containing the value N

- process all values smaller than N - i.e. traverse N's
*left*subtree. - process N itself.
- process all values bigger than N - i.e. traverse N's
*right*subtree.

How to traverse a BST in decreasing order?

Answer: right-to-left *infix* traversal.