C++ std::back_inserter方法代碼示例

 inline typename boost::enable_if< boost::is_directed_graph<Graph>,
 boost::tuple< typename boost::graph_traits<Graph>::vertex_descriptor,
               typename boost::property_traits<PositionMap>::value_type,
               typename Graph::edge_bundled > >::type 
   operator()(Graph& g,
              RRGVisitor vis,
              PositionMap g_position) const {
   typedef typename boost::property_traits<PositionMap>::value_type PositionValue;
   typedef typename boost::graph_traits<Graph>::vertex_descriptor Vertex;
   typedef typename Graph::edge_bundled EdgeProp;
   typedef boost::tuple< typename boost::graph_traits<Graph>::vertex_descriptor,
                         typename boost::property_traits<PositionMap>::value_type,
                         typename Graph::edge_bundled > ResultType;
   using std::back_inserter;
   
   while(true) {
     PositionValue p_new = get_sample(*space);
     
     std::vector<Vertex> Pred, Succ;
     select_neighborhood(p_new, back_inserter(Pred), back_inserter(Succ), g, *space, g_position);
     
     Vertex x_near; bool was_expanded; EdgeProp ep;
     boost::tie(x_near, was_expanded, ep) = detail::expand_to_nearest(p_new, Pred, g, vis);
     if( was_expanded )
       return ResultType(x_near, p_new, ep);
   };
   
   return ResultType();
 };

vector<string> vertex_cover(const graph g) {
	vector<connection> list;
	copy(g.begin(), g.end(), back_inserter(list));

	sort(list.begin(), list.end(), [](connection a, connection b) {
		return a.second.size() > b.second.size();
	});

	vector<string> cover;
	while (list.size()) {
		connection max = list.at(0);
		cover.push_back(max.first);

		list.erase(list.begin());

		for (string conc : max.second) {
			if (!list.size())
				break;

			auto to_remove = find_if(list.begin(), list.end(), [conc](connection c) {
				return c.first == conc;
			});

			if (to_remove != list.end()) {
				list.erase(to_remove);
			}
		}
	}

	return cover;
}

string find_best_key(vector<string> &v) {
    
   
    //Sort the vector by size
    //Gets the longest str length
    sort (v.begin(), v.end(), [](const string& s1, const string& s2){
	   return s1.size() < s2.size();
       }
    );
    
    //Gets the longest str length
    long longest_str_len = v.back().length();
    vector<string> best_keys;
    
    //only copy if the word is the largest
    copy_if(v.begin(), 
            v.end(), 
            back_inserter(best_keys), 
            [longest_str_len](string str) {
                return str.length() == longest_str_len;                        
            }
    );
         
    
    //sort by the value of the keys
    sort(best_keys.begin(), best_keys.end());
    
    //return the smallest key
    return best_keys[0];
     
        
    
}

int main()
{
	vector<int> vec(10);              // default initialized to 0
	fill(vec.begin(), vec.end(), 1);  // reset each element to 1

	// sum the elements in vec starting the summation with the value 0
	int sum = accumulate(vec.cbegin(), vec.cend(), 0);
	cout << sum << endl;
	
	// set a subsequence of the container to 10
	fill(vec.begin(), vec.begin() + vec.size()/2, 10);
	cout << accumulate(vec.begin(), vec.end(), 0) << endl;

	// reset the same subsequence to 0
	fill_n(vec.begin(), vec.size()/2, 0);
	cout << accumulate(vec.begin(), vec.end(), 0) << endl;

	// create 10 elements on the end of vec each with the value 42
	fill_n(back_inserter(vec), 10, 42);
	cout << accumulate(vec.begin(), vec.end(), 0) << endl;
	
	// concatenate elements in a vector of strings and store in sum 
	vector<string> v;
	string s;
	while (cin >> s)
		v.push_back(s);
	string concat = accumulate(v.cbegin(), v.cend(), string(""));
	cout << concat << endl;
	
	return 0;
}

void DevSetup::loadAudioDevices (AudioDevices const& d, QComboBox * cb, QAudioDeviceInfo const& device, QAudioDeviceInfo const& defaultDevice)
{
  using std::copy;
  using std::back_inserter;

  int currentIndex = -1;
  int defaultIndex = 0;
  for (AudioDevices::const_iterator p = d.cbegin (); p != d.cend (); ++p)
    {
      // convert supported channel counts into something we can store in the item model
      QList<QVariant> channelCounts;
      QList<int> scc (p->supportedChannelCounts ());
      copy (scc.cbegin (), scc.cend (), back_inserter (channelCounts));

      cb->addItem (p->deviceName (), channelCounts);
      if (*p == device)
	{
	  currentIndex = p - d.cbegin ();
	}
      else if (*p == defaultDevice)
	{
	  defaultIndex = p - d.cbegin ();
	}
    }
  cb->setCurrentIndex (currentIndex != -1 ? currentIndex : defaultIndex);
}

void spider::PageDownloader::download() const {
    using std::back_inserter;
    using std::string;
    using std::vector;

    try {
        Url const& url = getUrl();
        std::cerr << "Downloading page: " << url << std::endl;
    
        HttpResponse response = getResponse();

        int statusCode = response.getStatusCode();
        if (statusCode < 200 || statusCode >= 400) {
            return;  // ignore errors
        }
        if (statusCode >= 300 && statusCode < 400) {
            handleRedirect(response);
            return;
        }
        
        string content = getContent(response);
        
        vector<Url> urls;
        m_finder.getUrls(url, content, back_inserter(urls));
        
        m_manager.download(url, urls.begin(), urls.end());

    } catch (ConnectionException const& exception) {
        std::cerr << exception.what() << std::endl;
    }
}

int main()
{
  CGAL::set_pretty_mode(cout);

  // build a random convex 20-gon p
  {
    Polygon_2 p;
    random_convex_set_2(20, back_inserter(p), Point_generator(1.0));
    cout << "------------------------------\nInput:\n" << p << endl;
    compute(p.vertices_begin(), p.vertices_end());
  }

  // try identical points
  {
    Polygon_2 p;
    for (int i = 1; i < 3; ++i) {
      cout << "------------------------------\nInput:\n" << p << endl;
      compute(p.vertices_begin(), p.vertices_end());
      p.push_back(Point_2(0,0));
    }
  }


  return 0;
} 

double average_analysis(const Vec<Student_info>& students)
{
    Vec<double> grades;

    transform(students.begin(), students.end(),
              back_inserter(grades), average_grade);
    return median(grades);
}

void compute(ForwardIterator f, ForwardIterator l)
{
  // compute the minimal enclosing rectangle p_m of p
  Polygon_2 p_r;
  min_rectangle_2(f, l, back_inserter(p_r));
  cout << "Min_rectangle:\n" << p_r << endl;

  // compute the minimal enclosing parallelogram p_p of p
  Polygon_2 p_p;
  min_parallelogram_2(f, l, back_inserter(p_p));
  cout << "Min_parallelogram:\n" << p_p << endl;

  // compute the minimal enclosing strip p_s of p
  Line_2 lines[2];
  min_strip_2(f, l, lines);
  cout << "Min_strip:\n" << lines[0] << "\n" << lines[1] << endl;
}

vector<Student_info>
extract_fails(vector<Student_info>& students) {
	vector<Student_info> fail;
	remove_copy_if(students.begin(), students.end(),
	               back_inserter(fail), pgrade);
	students.erase(remove_if(students.begin(), students.end(),
	                         fgrade), students.end());
	return fail;
}

// median of the nonzero elements of `s.homework', or `0' if no such elements exist
double optimistic_median(const Student_info& s)
{
    Vec<double> nonzero;
    remove_copy(s.homework.begin(), s.homework.end(),
                back_inserter(nonzero), 0);

    if (nonzero.empty())
        return grade(s.midterm, s.final, 0);
    else
        return grade(s.midterm, s.final, median(nonzero));

void splitSentenceAndResult(const vector<string> &input, vector<string> *sentence, vector<vector<string>> *correctResultList) {
    for (const auto &str : input) {
        auto split = Utility::splitString(str);
        sentence->emplace_back(move(split[0]));
        vector<string> temp;
        temp.reserve(split.size() - 1);
        move(split.begin() + 1, split.end(), back_inserter(temp));
        correctResultList->emplace_back(move(temp));
    }
}

static bool_vec make_bool_vec(const std::string& str) {
  std::vector<bool> res;
  res.reserve(str.size());
  std::transform(begin(str), end(str), back_inserter(res), [](const char c) {
    assert(c == '0' || c == '1');
    return c == '1';
  });
  assert(res.size() == str.size());
  return res;
}

int main() {
    vector<int> vec{1, 2, 3, 4, 5, 6, 7, 8, 9, 0};
    list<int> lst;
    copy(vec.crbegin() + 3, vec.crend() - 3, back_inserter(lst));
    for (const auto i : lst){
        cout << i << ' ';
    }
    cout << endl;

    return 0;
}

vector<Point> chull(const vector<Point>& pst){
    vector<Point> points(pst);
    vector<Point> lupper,llower,edges;
    typedef vector<Point>::size_type vcs;

    sort(points.begin(),points.end(),point_order_x);
    vector<Point>::const_iterator it;

    //Constructing the upper hull. The point with lowest x will be part of
    //the hull
    lupper.push_back(points[0]);
    lupper.push_back(points[1]);

    //Loop the rest of the points to obtain the upper hull
    for(it=points.begin()+2;it!=points.end();++it){
        lupper.push_back(*it);

        //while size>2 and not a right turn
        while ((lupper.size() > 2) && !iscw(lupper))
            lupper.erase(lupper.end() - 2);
    }

    //Constructing the lower hull.
    it = points.end()-1;
    llower.push_back(*it);
    llower.push_back(*(it-1));

    for(it=points.end()-3;it>=points.begin();--it){
        llower.push_back(*it);

        //while size>2 and not a right turn
        while ((llower.size() > 2) && !iscw(llower))
            llower.erase(llower.end() - 2);

    }

    //First llower is already in lupper
    copy(lupper.begin(),lupper.end(),back_inserter(edges));
    copy(llower.begin()+1,llower.end(),back_inserter(edges)); 
    return edges;
}