说明：  哈夫曼编码(Huffman Coding)是一种可变字长编码(VLC)的编码方式。以哈夫曼树─即最优二叉树，带权路径长度最小的二叉树，经常应用于数据压缩。哈夫曼压缩是个无损的压缩算法，一般用来压缩文本和程序文件。
(Huffman encoding (Huffman Coding) is a variable length encoding (VLC) encoding method. Huffman tree, which is the best two fork tree, is the two fork tree with the smallest length of path. It is often applied to data compression. Huffman compression is a lossless compression algorithm, which is commonly used to compress text and program files.)