Approximation algorithms for the 2-peripatetic salesman problem with edge weights 1 and 2 Original Research Article

The NP-hard problem of finding two edge-disjoint Hamiltonian cycles of minimal total weight (also known as 2- PSPmin) in a complete (undirected) graph with edge weights 1 and 2 is considered. Polynomial time approximation algorithms are proposed with performance ratios 5/4 (in the case of one weight function) and 11/7 (in the case of two weight functions), respectively.