1）对给定的一份的文本文件，实现基于哈夫曼编码的文件压缩与解压操作。
2）该文件所包含的字符：26个字母的大小写、10种标点符号（一对双引号、一对单引号、冒号、逗号、分号、句号、问号以及感叹号）。
3）支持对以上业务实体内容的保存与打开等文件操作。(1) for a given text file, Huffman encoding file compression and decompression operation based on.

2) this document contains characters: 26 letters, 10 punctuation marks (of double quotes, a pair of single quotes, comma, colon, semicolon, full stop, question mark and exclamation mark).

3) documents to support the preservation of the above business entity content and open operation.)