23.6 Case Study: Graph Representation (cont.)

Represent graph using type of map
City name is the key, a DistanceToCity is the element
cities is a multimap; more than one edge may leave a city
multimap<string, DistanceToCity> CityMap;
(Adjacency list)
DistanceFinder wraps the multimap, provides 2 member functions:
- set_distance adds an edge to the graph
- find_distance fills in a map of destinations and their costs, given a source node