void ShdCrfTagger::tagging(sequence *s, label_t& ls)
{
instance_t ins;
this->ext(s, ins);
// build lattice
int length = ins.size();
vlattice_t l(length);
this->initlattice(l, ins);
// backtrack pointer
vynode_t *bt = this->viterbi(l);
ls.resize(length);
this->backtrack(bt, ls);
}
