一个完整的系统应具有以下功能：

(1) I：初始化（Initialization）。从终端读入字符集大小n，以及n个字符和n个权值，建立赫夫曼树，并将它存于文件hfmTree中。

(2) E：编码（Encoding）。利用已建好的赫夫曼树（如不在内存，则从文件hfmTree中读入），对文件ToBeTran中的正文进行编码，然后将结果存入文件CodeFile中。

(3) D：译码（Decoding）。利用已建好的赫夫曼树将文件CodeFile中的代码进行译码，结果存入文件Textfile中。

-A complete system should have the following features: (1) I: Initialization (Initialization). Read from the terminal character set size n, and n-n-weight character and to establish Huffman tree, and store it in the file hfmTree. (2) E: encoding (Encoding). Has been built using the Huffman tree (if it be not memory, read from the file hfmTree in), the body of the document ToBeTran the encoded file and then store the result in the CodeFile. (3) D: decode (Decoding). Huffman tree has been built using the code in the file CodeFile decoded, the result is stored in the file Textfile.