Preserving the values that the pointers stored in STL container point to (unordered_map)

[qutab]

I have a data structure as following

struct routing
{
        int color;	     //white = -1, gray = 0, black = 1
	unsigned int d;      //distance
	unsigned int pi;     //previous node id

	routing() : color (-1), d (UINT_MAX), pi (UINT_MAX ) {}
};

struct attraction //each node in graph is called an attraction
{
	unsigned int id;                           //id of node
	std::string name;                          //name
	unsigned int priority;                     //priority
	std::unordered_map<int, int> nodeMap;      //destination node id, distance
	routing r;                                 //routing information
		
	attraction() : id (0) , name(""), priority(0) {}
};

Now, I have to run the Dijkstra algorithm to find the shortest distance between different nodes (called attractions). I have implemented it and it's working just fine. Except that it's slow(er than I need).
I have an STL container which stores information about the nodes. I use this to perform the routing. It is given below:

//I use unordered_map for fast access of elements.
typedef std::unordered_map<unsigned int, attraction*> attractionList;
attractionList attrList;  

What I'm trying to do is once I calculate all the paths/costs of all the vertices from a certain node and store it in the attractionList container, I want to reuse this information, so that subsequent routing calls from that certain source node will be faster. For this I want to save the state of my attrList container, so I can quickly reuse the information stored. What I'm trying is something like this:

//make another container whose first element is a unique source id, second element is the attractionList 
std::unordered_map<unsigned int, attractionList> stateMap; (containig routing information)

attractionList newList = attrList; //make a new object to store old state

//insert in another container so that each unique source id has all routing information stored
stateMap.insert(std::pair<unsigned int, attractionList> (from, newList)); 

Well, the problem with this is obvious. When the pointers stored in the attrList change, all the copies made from it are invalid. Each time I call the algorithm on a new source node I have to reset the data of all nodes, so it invalidates my previously 'stored' states. How do I store them permanently? How is the copying being done in this container? If necessary how do I overload the assignment operator? Is this even possible? I can make slight changes to my data structure and containers but not much.

Sorry for the long post. Thank you in advance.