On the complexity of finding well-balanced orientations with upper bounds on the out-degrees
We show that the problem of deciding whether a given graph G has a well-balanced orientation G⃗ such that d_G⃗^+(v)≤ℓ(v) for all v ∈ V(G) for a given function ℓ:V(G)→ℤ_≥ 0 is NP-complete. We also prove a similar result for best-balanced orientations. This improves a result of Bernáth, Iwata, Király, Király and Szigeti and answers a question of Frank.
READ FULL TEXT