撰写一个程序，能够构建字符串型的二叉排序树并在二叉排序树中查找节点。

所谓二叉排序树，简而言之，是一个每个节点可指向 0、1 或 2 个节点的递归的数据结构。最上层的一个节点称为树根。二叉排序树服从凡是比当前节点小的值都在其左下方，比当前节点大的值都在其右下方的规律。该规律不仅适用于树的局部，也适用于整棵二叉排序树。-Write a program to build string of binary sort tree and binary sort tree to find nodes. The so-called binary search tree, in short, is a point to each node can be 0, 1 or 2 nodes recursive data structures. The top node is called root. Binary sort tree to obey any smaller value than the current node in its lower left, larger than the current value of the node in the bottom right of the law. The law applies not only to the local tree, also apply to whole grain binary sort tree.