说明：  对读入的某个文本文件input.txt中，拆出英文单词，输出一个按字典顺序排列的单词表，结果输出在文本文件output.txt中，每个单词一行，并在单词后输出该单词出现的个数，两个字段之间用逗号分隔。约定单词仅由英文字母组成，单词间由非英文字母分隔，相同单词只输出一个，大小写不区分。 利用二叉树实现
(the right time to a text file input.txt, divestment English words, Output by an order of the dictionary word list, the result output in a text file output.txt. Every word here, and the output of the word after word of the number, between two fields separated by a comma. Agreed only by the words in alphabetical composition, word by non-alphabetic segregation, the same word is only one output, distinction is not case. Achieved using binary tree)