说明：  哈夫曼编码(Huffman Coding)是一种编码方式，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。是指使用一张特殊的编码表将源字符（例如某文件中的一个符号）进行编码
(Huffman coding (Huffman Coding) is an encoding, the Huffman tree ─ that is optimal binary tree, the minimum weighted path length of the binary tree, often used in data compression. Is the use of a specific character encoding table source (for example, a symbol of a file) to encode)