Are Stable Instances Easy?

Are Stable Instances Easy?

We introduce the notion of a stable instance for a discrete optimization problem, and argue that in many practical situations only sufficiently stable instances are of interest. The question then arises whether stable instances of NP–hard problems are easier to solve. In particular, whether there exist algorithms that solve correctly and in polynomial time all sufficiently stable instances of s...

Innovations in Computer Science 2010 Are Stable Instances Easy ? ∗

We introduce the notion of a stable instance for a discrete optimization problem, and argue that in many practical situations only sufficiently stable instances are of interest. The question then arises whether stable instances of NP–hard problems are easier to solve. In particular, whether there exist algorithms that solve correctly and in polynomial time all sufficiently stable instances of s...

Easy instances for model checking

Lösung des jeweiligen Model-Checking Problems " nur " noch die Teilergeb-nisse zusammengesetzt werden. Auf diese Weise lösen wir die vier angespro-chenen Model-Checking Probleme für die Logik der ersten Stufe auf lokal baumartigen Strukturen (nicely locally tree-decomposable classes). Diese Algorithmen arbeiten alle in Zeit linear in der Größe der Eingabestruktur (plus der Größe der Ausgabe bei...

Distinguishing Easy and Hard Instances

Easy Instances Of The Plant Location Problem

In this paper we describe properties of a particular transformation of the simple plant location problem into a vertex packing problem on a corresponding undirected graph. We characterize the undirected graphs that arise from simple plant location problems and we give a necessary and su cient condition for such graphs to be perfect. This allows us to nd a new family of polynomially solvable ins...