说明：  哈夫曼编码是一种常用的数据压缩技术，对数据文件进行哈夫曼编码可大大缩短文件的传输长度，提高信道利用率及传输效率。要求采用哈夫曼编码原理，统计文本文件中字符出现的词频，以词频作为权值，对文件进行哈夫曼编码以达到压缩文件的目的，再用哈夫曼编码进行译码解压缩。 统计待压缩的文本文件中各字符的词频，以词频为权值建立哈夫曼树，并将该哈夫曼树保存到文件中。
(Huffman coding is a commonly used data compression technology, Huffman coding data files can greatly reduce transmission length of the file, to improve channel utilization and transmission efficiency. Require the use of Huffman coding theory, word frequency statistics characters appear in the text file to word frequency as weights, the file compression Huffman coding to achieve the purpose of the document, and then Huffman decoding decompression. Statistical text file to be compressed term frequency of each character, word frequency as weights to build the Huffman tree, and save the Huffman tree to a file.)