A better list heuristic for vertex cover
Résumé
François Delbot and Christian Laforest develops a better list heuristic for vertex cover. A vertex cover C of G is a subset of vertices such that every edge e = uv ε E contains at least one vertex of C: C ⊂ V and ∀e =uv, u ε C or v ε C. In spite of these difficulties, the authors propose an online algorithm in which the scanned vertex is selected if and only if it has at least a nonselected already revealed neighbor with competitive ratio of ∇. Another type of interesting variation is what D. Avis and T. Imamura call the list heuristic. In this model, an algorithm scans the vertices one by one in a fixed given order called a list. A list algorithm scans the list only once and takes a definitive decision of selection for the currently scanned vertex. This can be viewed as an intermediate model between traditional approximation algorithms or heuristics.