如何在C ++中向std :: priority_queue添加键/优先级？

Question

I'm trying to implement Dijkstra's Pathfinding Algorithm using the std::priority_queue . My Queue is of type Node* and I need it to prioritize based on a float gScore stored inside Node from smallest gScore to largest. I've read the documentation but I still don't understand how this can be achieved. Any ideas?

I don't understand what the type means by container_type(vector)

std::priority_queue<Node*> queue;

I greatly appreciate any help!

Answer 1

You can create a class which will overload ()

class cmp
{ 
   public:
   bool operator()(const Node *a, const Node *b) const
   {
      return (a->gscore) > (b->gscore);
   }
 };

Then

 std::priority_queue<Node*,std::vector<Node*>,cmp);

Answer 2

You will need a comparator function. I think it would be better to implement in a manner given below , rather than declaring a class for it.

auto comp = [] (Node* a,Node* b) -> bool { return a->gscore < b->gscore; };
priority_queue< Node*, std::vector<Node*>, decltype(comp) > foo(comp);