C++ forward_list::end方法代码示例

void removeDupsNoBuffer(std::forward_list<int>& l) {
    if (l.empty())
        return;
    auto backtrack = l.before_begin();
    while (std::next(backtrack) != l.end()) {
        // Iterate and print values of the list
        for (int n : l)
            std::cout << n << '\t';
        std::cout << std::endl;

        auto prev = std::next(backtrack);
        auto iter = std::next(prev);
        //std::cout << " prev =" << *prev << ", iter=" << *iter << std::endl;
        while (iter != l.end()) {
            if (*iter == *std::next(backtrack))
                iter = l.erase_after(prev);
            else {
                ++prev;
                ++iter;
            }
                
        }
        ++backtrack;
    }
}

int midList(std::forward_list<int> l){

	int mid = std::distance(l.begin(), l.end()); //Size of Linked List
	
	
	if( mid % 2 == 0) //Even digits two mid
	{
		int k = 0;
		for(auto i = l.begin(); i != l.end(); ++i){

			if(++k == mid/2)
				return *i; 
		}

	}else{ //Odd Digits mid + 1

	int k = 0;
	for(auto i = l.begin(); i != l.end(); ++i){

		if(++k == mid/2 + 1)
				return *i; 

	}
        }
	return -1;
}

int iReturn(std::forward_list<int> l, int n){

	int k = 0;

	for(auto i = l.begin(); i != l.end(); ++i){
		if(++k == std::distance(l.begin(), l.end()) - n + 1)
			return *i;
	}
}

int detectLoop(std::forward_list<int> l){

	auto p1 = l.begin(), p2 = l.begin();	 //Initialise two pointers to head

	while(p1 != l.end() && p2 != l.end() && std::next(p2, 1) != l.end()){ //Move p1 by 1 and p2 by 2 positions
		
		if(*(++p1) == *(++(++p2))){ //Element p1 and p2 are equal -> loop
			return 1;
		}
	}
	return 0;
} 

void AudioStreamingServer::SendMediaList(const std::shared_ptr<ISocket>& clientSocket, const std::string& keyword, const std::string& hostName) const {
    
    const std::forward_list<const std::string*> files = audioLibrary->Search(keyword);
    std::vector<std::string> urls;
    urls.reserve(std::distance(files.begin(), files.end()));
    
    int responseSize = 0;
    for(const std::string* file : files) {
        std::string encodedFile = urlCodec->EncodeURL(*file);
        std::string url;
        url.reserve(hostName.length() + encodedFile.length() + 9); //account 2 for '/', '\n' and 7 for 'http://'
        url += "http://";
        url += hostName;
        url += '/';
        url += encodedFile;
        url += '\n';
        responseSize += url.length();
        urls.push_back(std::move(url));
    }

    HttpResponse response(HTTP_1_1, OK, M3U, responseSize, keyword + ".m3u");
    SendResponseHeader(clientSocket, response);
    for(const std::string& url : urls) {
        clientSocket->Send(url.c_str(), url.size());
    }
}

std::forward_list<B> map (std::function<B(A)> f, const std::forward_list<A>& L) 
{
  std::forward_list<B> H;
  std::transform(L.begin(), L.end(), std::front_inserter(H), f);
  H.reverse();
  return H;
}

void
TraialPool::return_traials(std::forward_list< Reference< Traial > >& list)
{
	for (auto it = list.begin() ; it != list.end() ; it = list.begin()) {
		available_traials_.push_front(*it);
		list.pop_front();  // 'it' got invalidated
	}
}

std::forward_list<std::tuple<A,B>> zip (const std::forward_list<A>& L, const std::forward_list<B>& M) 
{
  std::forward_list<std::tuple<A,B>> H;
  auto zipper = [] (const A& a, const B& b) {return std::make_tuple(a,b);};
  std::transform(L.begin(), L.end(), M.begin(), std::front_inserter(H), zipper);
  H.reverse();
  return H;
}

static int
fbsd_is_vfork_done_pending (pid_t pid)
{
  for (auto it = fbsd_pending_vfork_done.begin ();
       it != fbsd_pending_vfork_done.end (); it++)
    if (it->pid () == pid)
      return 1;
  return 0;
}

void Creature::startAutoWalk(const std::forward_list<Direction>& listDir)
{
	listWalkDir = listDir;

	size_t size = 0;
	for (auto it = listDir.begin(); it != listDir.end() && size <= 1; ++it) {
		size++;
	}
	addEventWalk(size == 1);
}

TEST(std_forward_list, clear) {
  std::forward_list<int> l1{0, 0, 0, 0};
  const std::forward_list<int> l2{1, 2, 3};

  l1.clear();
  ASSERT_TRUE(l1.begin() == l1.end());

  l1.insert_after(l1.before_begin(), l2.begin(), l2.end());
  ASSERT_TRUE(l1 == l2);
}

//Iterative
void iReverse(std::forward_list<int> &l){

	std::forward_list<int> s = l, r;
	
	for(auto i = l.begin(); i != l.end(); ++i) //Iterate, pop  and push into r
	{
		r.push_front(s.front());
		s.pop_front();	
	}
	l = r; //Assign s to l
}

void InsertString(std::forward_list<std::string> &s, const std::string &s1, const std::string &s2)
{
    std::forward_list<std::string>::iterator a, prev = s.before_begin();

    for (a = s.begin(); a != s.end(); ++a, ++prev) {
        if (*a == s1) {
            s.insert_after(a, s2);
            return;
        }
    }
    s.insert_after(prev, s2);
}

 inline std::string PrettyPrint(const std::forward_list<T, Allocator>& listtoprint, const bool add_delimiters=false, const std::string& separator=", ")
 {
     std::ostringstream strm;
     if (listtoprint.size() > 0)
     {
         if (add_delimiters)
         {
             strm << "[";
             typename std::forward_list<T, Allocator>::const_iterator itr;
             for (itr = listtoprint.begin(); itr != listtoprint.end(); ++itr)
             {
                 if (itr != listtoprint.begin())
                 {
                     strm << separator << PrettyPrint(*itr, add_delimiters, separator);
                 }
                 else
                 {
                     strm << PrettyPrint(*itr, add_delimiters, separator);
                 }
             }
             strm << "]";
         }
         else
         {
             typename std::forward_list<T, Allocator>::const_iterator itr;
             for (itr = listtoprint.begin(); itr != listtoprint.end(); ++itr)
             {
                 if (itr != listtoprint.begin())
                 {
                     strm << separator << PrettyPrint(*itr, add_delimiters, separator);
                 }
                 else
                 {
                     strm << PrettyPrint(*itr, add_delimiters, separator);
                 }
             }
         }
     }
     return strm.str();
 }

//Using two pointers
int pReturn(std::forward_list<int> l, int n){

	auto i1 = l.begin(), i2 = l.begin();

	std::advance(i1, n); //Move iterator to n places
	
	while(i1 != l.end()){
		++i1;
		++i2;
	}

	return *i2; 
}