/** Buils a wt_coder_huff using the sequence of length n and the alphabet_mapper
* to determine the huffman codes */
wt_coder_huff(uint *symbs, uint n, alphabet_mapper * am);
+ wt_coder_huff(uchar *symbs, uint n, alphabet_mapper * am);
virtual ~wt_coder_huff();
virtual bool is_set(uint symbol, uint l);
virtual bool done(uint symbol, uint l);