说明：  较实用的赫夫曼编码：可统计给定文件里面的字符数（在此当作频度），不用手动输入各字符集及频度。只需按提示将要压缩的文件（除去汉字否则出错，其他128个字符均可）路径给出便可！压缩一种是字符型的，为了直观的看是否真编码，一种是真压缩，要编码文件越大其压缩越高，因为这个编码在解码是要赫夫曼树
(More practical Huffman coding: The statistics given the number of characters inside a document (in this as a frequency), no need to manually enter each character set and the frequency. Just follow the prompts that will be compressed file (or else remove the characters wrong, the other 128 characters can be) given path can be! One is the character of compression, in order to see whether it is really intuitive coding, one is really compressed, encoded files to the greater of its higher compression, because the coding in the decoder is to Huffman tree)