说明：  自适应(或动态)哈夫曼算法取消了统计，可在压缩数据时动态调整哈夫曼树，这样可提高速度。因此，哈夫曼编码效率高，运算速度快，实现方式灵活。
(Adaptive (or dynamic) Huffman algorithm to cancel the statistics, the data can be dynamically adjusted in the compressed Huffman tree, which can improve speed. Therefore, the Huffman coding efficiency, fast speed, to achieve flexible.)