In recent years approximation algorithms based on primal-dual methods have been successfully applied to a broad class of discrete optimization problems. In this paper, we propose a generic primal-dual ...

The Traveling Salesman Problem with Backhauls (TSPB) is defined on a graph G = (V, E). The vertex set is partitioned into V=({v1},L,B), where v1 is a depot, L is a set of linehaul customers, and B is ...