Now my problem is that I have to do this search many, many times - performance is very important - and I don't want to initialize the values for a half a million nodes when I'm only going to visit 20. I therefore want to use a std::map to store distances, and I want a key missing from that map to indicate an unvisited node, right? Another option would be to use a combination of a vector and a list of visited nodes. Initialize the full vector only once, and for every search re-initialize those nodes in the list and clear the list. The list can be made using the Visitor that you already use to escape
On 11/05/2011 23:40, Fletcher Foti wrote: the algorithm. The advantage is that the algorithm will find its values in a vector which is faster than a map. (AFAIK) -- Alex