HuffmanTree

代码说明：

  读SourceFile.txt文件，对出现的字母进行哈夫曼编码，输出编码表到Code.txt,并用构建得的编码对SourceFIle.txt进行编码。(Read the SourceFile.txt file, Huffman encoding the letters that appear, output the encoding table to Code.txt, and encode SourceFIle.txt with the constructed encoding.)