Counting feasible solutions of the traveling salesman problem with pickups and deliveries is #P # P -complete
Deciding whether or not a feasible solution to the Traveling Salesman Problem with Pickups and Deliveries  (TSPPD) exists is polynomially solvable. We prove that counting the number of feasible solutions of the TSPPD is hard by showing that the problem is #P # P -complete.
traveling salesman problem with pickups and deliveries counting solutions #p # p -complete #p # p #p # p # p complexity