(1) 从终端读入字符集大小为n（即字符的个数），逐一输入n个字符和相应的n个权值（即字符出现的频度），建立哈夫曼树，将它存于文件 hfmtree 中。并将建立好的哈夫曼树以树或凹入法形式输出 对每个字符进行编码并且输出。

(2) 利用已建好的哈夫曼编码文件 hfmtree ，对键盘输入的正文进行译码。输出字符正文，再输出该文的二进制码。

-(1) read from the terminal into the character set of size n (ie the number of characters), each input n characters and the corresponding n-weight (ie, the frequency of characters appear), establishing a Huffman tree, it would be kept hfmtree in the document. Will establish a good Huffman tree to tree or indentation law form output　for each character is encoded and output. (2) the use of Huffman coding has been completed document hfmtree, the body of the keyboard input for decoding. Output characters in the body, and then outputs the binary code in the text.