// [[Rcpp::export]]
List get_idf_cpp(List x,Nullable<CharacterVector> stop_) {
IDFmap m;
for(ListOf<CharacterVector>::iterator it = x.begin();it != x.end();it++){
unsigned int dis = distance( x.begin(), it );
auto tmp = as<CharacterVector>(*it);
inner_find(tmp,m,dis);
}
RCPP_UNORDERED_MAP< string,unsigned int > res;
unordered_set<string> st;
if(!stop_.isNull()){
CharacterVector stop_value = stop_.get();
const char *const stop_path = stop_value[0];
_loadStopWordDict(stop_path,st);
for(auto its= m.begin();its!=m.end();its++){
if(st.find((*its).first) ==st.end()) res[(*its).first] = (*its).second.second;
}
return wrap(res);
}
for(auto its= m.begin();its!=m.end();its++){
res[(*its).first] = (*its).second.second;
}
return wrap(res);
}
void inner_find(CharacterVector& y,IDFmap& m,unsigned int dis){
for(CharacterVector::iterator it = y.begin();it!=y.end();it++){
string tmp = as<string>(*it);
IDFmap::iterator m_it = m.find(tmp);
if(m_it==m.end()){
m[tmp].first=dis;
m[tmp].second=1;
}else{
if((*m_it).second.first != dis){
(*m_it).second.first = dis;
(*m_it).second.second =(*m_it).second.second+1;
}
}
}
}
// [[Rcpp::export]]
List get_idf_cpp(List x,Nullable<CharacterVector> stop_) {
IDFmap m;
for(ListOf<CharacterVector>::iterator it = x.begin();it != x.end();it++){
unsigned int dis = distance( x.begin(), it );
auto tmp = as<CharacterVector>(*it);
inner_find(tmp,m,dis);
}
vector<string> sts;
vector<double> stn;
sts.reserve(m.size());
stn.reserve(m.size());
unordered_set<string> st;
double xsize = x.size();
if(!stop_.isNull()){
CharacterVector stop_value = stop_.get();
const char *const stop_path = stop_value[0];
_loadStopWordDict(stop_path,st);
for(auto its= m.begin();its!=m.end();its++){
if(st.find((*its).first) ==st.end()){
sts.push_back((*its).first);
stn.push_back( log(xsize / (*its).second.second) );
}
}
}else{
for(auto its= m.begin();its!=m.end();its++){
sts.push_back((*its).first);
stn.push_back((*its).second.second);
}
}
vector<string> row_names;
row_names.reserve(sts.size());
for (unsigned int i = 0; i < sts.size(); ++i) {
row_names.emplace_back(int64tos(i));
}
List res = List::create(_["name"] = wrap(sts),_["count"] = wrap(stn));
res.attr("row.names") = row_names;
res.attr("names") = CharacterVector::create("name","count");
res.attr("class") = "data.frame";
return res;
}