二叉排序树，实现树的各种操作，包括计算深度，找最大值最小值，还有各种遍历的递归算法和非递归算法，以及查找查找树的前驱节点和后继节点-Binary sort tree, the tree to achieve various operations, including the calculation of depth, looking for maximum minimum, there are various recursive traversal algorithm and non-recur