C++ map::cbegin方法代码示例

void grouped_vocabulary_tree<Point, K>::merge_maps(map<int, int>& map1, const map<int, int>& map2)
{
    using iter = map<int, int>::iterator;
    using citer = map<int, int>::const_iterator;

    iter it1 = map1.begin();
    citer it2 = map2.cbegin();
    iter end1 = map1.end();
    citer end2 = map2.cend();
    while (it2 != end2) {
        bool done1 = it1 == end1;
        if (!done1 && it1->first == it2->first) { // element already in 1, just increase count
            it1->second += it2->second;
            ++it1;
            ++it2;
        }
        else {
            if (done1 || it1->first > it2->first) {
                // from c++11 docs:
                // The function optimizes its insertion time if position points to the element
                // that will follow the inserted element (or to the end, if it would be the last).
                map1.insert(it1, *it2);
                ++it2;
            }
            else {
                ++it1; // if map1 is large while map2 is small this will not give better than const time insertion
            }
        }
    }
}

int Database::GetRecordByFields(const string tableName, map<string, string> fieldValues, vector< map<string, string> >* out, string sortField, bool bAsc) const
{
	if (!Util::IsLetterNumberDash(tableName) || !Util::IsLetterNumberDash(sortField))
		return 2;

	string order = " ORDER BY " + sortField + (bAsc ? " ASC;" : " DSC;");
	string sql = "SELECT * FROM " + tableName + " WHERE ";

	auto it = fieldValues.cbegin();
	while (it != fieldValues.cend())
	{
		if (!Util::IsLetterNumberDash((*it).first))
			return 2;
		sql.append(Util::ToUpper((*it).first + "='"));
		//*TODO: Check value
		sql.append((*it).second + "'");

		++it;
		if (it != fieldValues.cend())
			sql.append(" AND ");
	}

	sql += order;

	return Exec(sql, out);
}

void map_intersection(map<Key, Value>& lhs, map<Key, Value> const& rhs)
{
    typedef typename map<Key, Value>::iterator input_iterator1;
    typedef typename map<Key, Value>::const_iterator input_iterator2;

    input_iterator1 it1 = lhs.begin();
    input_iterator2 it2 = rhs.cbegin();
    input_iterator1 end1 = lhs.end();
    input_iterator2 end2 = rhs.cend();
    while (it1 != end1 && it2 != end2) {
        if (it1->first == it2->first) {
            it1->second += it2->second;
            ++it1;
            ++it2;
        }
        else {
            if (it1->first < it2->first) {
                ++it1;
            }
            else {
                ++it2;
            }
        }
    }
}

void EulerUtils::Display::printMap ( string itemName, const map<string, int>& data ) {
	cout << "in printMap" << endl;
	cout << "Printing " << itemName << "..." << endl;
	for ( auto i = data.cbegin(); i != data.cend(); i++ )
        cout << i->first << ": " << i->second << endl;
    cout << endl;
}

int Database::AddRecord(const string tableName, const map<string, string> newEntry)
{
	if (!Util::IsLetterNumberDash(tableName))
		return 2;

	string sql = "INSERT INTO " + tableName + " (";
	
	auto it = newEntry.cbegin();
	while(it != newEntry.cend())
	{
		if (!Util::IsLetterNumberDash((*it).first))
			return 2;

		if (Util::ToUpper((*it).first).compare("ID") == 0)
		{
			++it;
			continue;
		}

		sql.append(Util::ToUpper((*it).first));

		++it;
		if (it != newEntry.cend())
			sql.append(",");
		else
			sql.append(") ");
	}

	sql.append("VALUES(");
	it = newEntry.cbegin();
	while (it != newEntry.cend())
	{
		//*TODO: Check values
		sql.append("'" + (*it).second + "'");

		++it;
		if (it != newEntry.cend())
			sql.append(",");
		else
			sql.append(");");
	}

	return Exec(sql);
}

void Model::AddFeasCat(map<string, int> feaofcat, string catname,int threshold)
{
	auto itfc = feaofcat.cbegin();
	int count = 1;
	while (itfc != feaofcat.cend())
	{
		if (itfc->second <= threshold)
		{
			++itfc;
			continue;
		}
		stringstream query;
		query<< "insert into fc (feature,cat,count) values ('" << itfc->first << "','" << catname << "'," << itfc->second << ")";
		this->ExecuteSQL(query.str().c_str());
		++itfc;
	}
}

std::string RelationManager::showMap(const map<const Class *, set<const Class *> > &map, std::string msg) const
{
	std::string s;

	if (map.empty()) return "";

	if (msg != "")
		s.append(msg + "\n");
	for (auto i = map.cbegin(); i != map.cend(); i++) {
		s.append(i->first->getName() + ": ");
		for (auto j = i->second.cbegin(); j != i->second.cend(); j++)
			s.append((*j)->getName() + " ");
		s.append("\n");
	}

	return s.append("\n");
}

bool Model::contained_in( map<unsigned int, shared_ptr<list< shared_ptr<pair_sc> > > > &m, 
   const shared_ptr<pair_sc> & sc, bool opt, bool debug) {

  for( auto iitm = m.cbegin(); iitm != m.cend(); iitm ++) {

          if (sc->signature != (sc->signature | iitm->first)) continue;

	  for ( auto il = iitm->second->begin(); il != iitm->second->end(); il++) { 
	      if( (*il)->contains(sc, fpfp_sim))
		      return true;	    
          }
  }

  if ( !opt) return false;

  for( auto iitm = m.begin(); iitm != m.end(); iitm ++) {

          if (iitm->first != (sc->signature | iitm->first)) continue;

          auto ed = iitm->second;

	  //for ( unsigned i = 0; i < ed->size(); i++) { 
	  for ( auto il = ed->begin(); il != ed->end(); il++) { 
              if ( ! (*il)->valid) {
                if (!debug)
                  ed->erase(il++);
                continue;
              }
	      if( sc->contains(*il, fpfp_sim)) {
                (*il)->clean_children();
                if (debug)
                  (*il)->valid = false;
                else
                  ed->erase(il++);
              }
	  }
  }
  return false;
}

void Book::addTransactions(map<float, int>& _transactions)
{
    if (_transactions.size() > 0)
        addTransactions(_transactions.cbegin(), _transactions.cend());
}

static int size(const map<unsigned int, shared_ptr<list<shared_ptr<pair_sc> > > > &m) {
  int s = 0;
  for( auto iitm = m.cbegin(); iitm != m.cend(); iitm ++)
    s += iitm->second->size();
  return s;
}