从键盘上输入一串正整数， 最后输入－1作为输入结束的标志。如输入的序列为：2，5，7，23，48，96，……，-1。请以这些正整数的值作为二叉排序树中的结点的数据场之值，建立一棵二叉排序树。注意：请采用动态存储方法保存这棵二叉排序树，事先并未知道该二叉排序树中的结点的个数。-Enter the string from the keyboard, a positive integer, the last input-1 as the input end of the sign. If the input sequence: 2,5,7,23,48,96, ... ...,-1. Please these are integer values as binary sort tree nodes in the value data field, the establishment of a binary sort tree. Note: Please save the tree by dynamic storage for binary sort tree, did not know in advance that the binary sort tree, the number of nodes.