在电报收发、数据通信过程中，可使用前缀编码使字符编码的平均长度最短。这种前缀编码可通过构造哈夫曼树的方式来实现。

算法输入：各字符及其权值。

算法输出：各字符的编码串

-In his cable, transceiver, data communication process, can use the prefix encoding character encoding so that the average length of the shortest. This prefix Huffman coding tree structure can be a way to achieve. Algorithm input: the characters and their weight. Algorithm output: the character encoding string