We consider the combinatorial stack-up problem motivated by stacking up bins from a conveyor onto pallets. The stack-up problem is to decide whether a given list q of labeled objects can be processed by removing step by step one of the first s objects of q so that the following holds. After each...

We consider the combinatorial stack-up problem motivated by stacking up bins from a conveyor onto pallets. The stack-up problem is to decide whether a given list q of labeled objects can be processed by removing step by step one of the first s objects of q so that the following holds. After each...

The knapsack problem is one of the simplest and most fundamental NP-hard problems in combinatorial optimization. We consider two knapsack problems which contain additional constraints in the form of directed graphs whose vertex set corresponds to the item set. In the one-neighbor knapsack...

The subset sum problem is one of the simplest and most fundamental NP-hard problems in combinatorial optimization. We consider two extensions of this problem: The subset sum problem with digraph constraint (SSG) and subset sum problem with weak digraph constraint (SSGW). In both problems there...