哈夫曼树是一种带权路径长度最短的树。 所谓路径长度就是某个端结点到树的根结点的距离,等于该端结点的祖先数,或该结点所在层数减1,用lk表示。-Huffman tree is a weighted length of the shortest path tree. The so-called path length is a client node to the tree root node of the distance, equal to the end of the ancestors of