21. Binary search trees are the most simplest, yet most common type of tree for this implementation. 22. The algorithm works as follows : consider a binary search tree for the items in question. 23. This fact should be considered when choosing the potential search tree and implementing the pruning test. 24. I'm implementing a binary search tree in D with a Node class and a BinaryTree class. 25. In other words, it allows for a backjump only at leaf nodes in the search tree . 26. The above picture is a balanced ternary search tree for the same set of 12 words. 27. Self-balancing binary search trees apply this operation automatically. 28. The ChessBrain project was a chess program that distributed the search tree computation through the Internet. 29. AVL trees and red-black trees are two examples of binary search trees that use the left rotation. 30. In addition, and like all binary search trees, self-balancing binary search trees keep their elements in order.