Is there an efficient algorithm which gives the minimum cost closed walk in an undirected graph, which visits all vertices?
Does this problem have a name? I tried to reduce this to similar problems (in particular the traveling salesman problem) to see if it was NP-hard, but was unsuccessful.
Here's an example:
Then a possible closed walk is: A,B,C,D,C,B,A, with a cost of 6.
Thanks!