algorithm - Variation of TSP which visits multiple cities

Question

I am looking to discuss branch and bound solution for TSP with multiple visits.(that is every city needs to be visited atleast once , instead of just once)

Edit:

Removed the doubt as it was not relevant as pointed by Jitse. Now the question is more clear.

Answer 1

Simply augment the graph by adding, for each pair of nodes A and B, an edge representing the shortest path from A to B. The Floyd-Warshall algorithm allows you to do this in O(n^3), which is much faster than any TSP algorithm. Once you've done this, use a standard TSP branch and bound technique. This site has some information from Applegate's book, which discusses branch and bound for TSP according to the Wikipedia TSP entry.