二叉树的排序！前序，中序及后序，并求其深度-Binary tree sort! Pre-order, middle order and post order, and to seek its depth

用visual c++ 2008写的关于二叉树读取、前序、中序和后序遍历算法。调试成功，很好用。-With visual c++ 2008 to write about the binary read, pre-order, the order and post order traversal algorithm. Debugging success, is useful.