构造任意k元（k≥2）Huffman树算法,k元哈夫曼树的构造与2元哈夫曼树的构造相同，差别只在于k元哈夫曼树需考虑虚设的0的个数。-Construct an arbitrary k-ary (k ≥ 2) Huffman tree algorithm, k element of the Huffman tree structure with two yuan the same Huffman tree structure, the difference lies in k-ary Huffma