template<class _Ty, class _Container = vector<_Ty>, class _Pr = less<typename _Container::value_type> > //默认以vector为容器的
class priority_queue
{   // priority queue implemented with a _Container
public:  typedef _Container container_type;  typedef typename _Container::value_type value_type;  typedef typename _Container::size_type size_type;  typedef typename _Container::reference reference;  typedef typename _Container::const_reference const_reference;  priority_queue() : c(), comp()  {   // construct with empty container, default comparator  }  explicit priority_queue(const _Pr& _Pred) : c(), comp(_Pred)  {   // construct with empty container, specified comparator  }  priority_queue(const _Pr& _Pred, const _Container& _Cont) : c(_Cont), comp(_Pred)  {   // construct by copying specified container, comparator  make_heap(c.begin(), c.end(), comp); //参见《STL系列之四 heap 堆的相关函数》  }  template<class _Iter>  priority_queue(_Iter _First, _Iter _Last) : c(_First, _Last), comp()  {   // construct by copying [_First, _Last), default comparator  make_heap(c.begin(), c.end(), comp);  }  template<class _Iter>  priority_queue(_Iter _First, _Iter _Last, const _Pr& _Pred) : c(_First, _Last), comp(_Pred)  {   // construct by copying [_First, _Last), specified comparator  make_heap(c.begin(), c.end(), comp);  }  template<class _Iter>  priority_queue(_Iter _First, _Iter _Last, const _Pr& _Pred, const _Container& _Cont) : c(_Cont), comp(_Pred)  {   // construct by copying [_First, _Last), container, and comparator  c.insert(c.end(), _First, _Last);  make_heap(c.begin(), c.end(), comp);  }  bool empty() const  {   // test if queue is empty  return (c.empty());  }  size_type size() const  {   // return length of queue  return (c.size());  }  const_reference top() const  {   // return highest-priority element  return (c.front());  }  reference top()  {   // return mutable highest-priority element (retained)  return (c.front());  }  void push(const value_type& _Pred)  {   // insert value in priority order  c.push_back(_Pred);  push_heap(c.begin(), c.end(), comp);  }  void pop()  {   // erase highest-priority element  pop_heap(c.begin(), c.end(), comp);  c.pop_back();  }  protected:  _Container c;   // the underlying container  _Pr comp;   // the comparator functor
};

struct node
{friend bool operator< (node n1, node n2){return n1.priority < n2.priority;}int priority;int value;
};