Titlebook: Mathematical Foundations of Computer Science 2004; 29th International S Jiří Fiala,Václav Koubek,Jan Kratochvíl Conference proceedings 2004

OUTRE

斥责

Online Algorithms for Disk Graphslting from intersections of disks on the plane. In particular, we investigate whether randomization can be used to break known lower bounds for deterministic on-line independent set algorithms and present new upper and lower bounds; we also present an improved upper bound for on-line coloring.

Geyser

爆炸

DEBT

fructose

On Approximation Hardness of the Minimum 2SAT-DELETION Problem hierarchy of minimization problems [8], and its approximability is largely open. We prove a lower approximation bound of ., improving the previous bound of . by Dinur and Safra [5]. For highly restricted instances with exactly 4 occurrences of every variable we provide a lower bound of .. Both inap

精致

Group Coloring and List Group Coloring Are Π, ,-Completeignment ., there exists a vertex-coloring .: .(.)→ . with .(.)∈ .(.) for each vertex . and with . for each oriented edge . of .. We prove a dichotomy result on the computational complexity of this problem. In particular, we show that the problem is Π.-complete if ℓ≥ 3 for any group . and it is polyn

珐琅

delegate

Equitable Colorings of Bounded Treewidth Graphs has size at most ℓ. We consider the problems to determine for a given graph . (and a given integer ℓ) whether . has an equitable (ℓ-bounded) .-coloring. We prove that both problems can be solved in polynomial time on graphs of bounded treewidth, and show that a precolored version remains NP-complete on trees.

objection

Online Algorithms for Disk Graphslting from intersections of disks on the plane. In particular, we investigate whether randomization can be used to break known lower bounds for deterministic on-line independent set algorithms and present new upper and lower bounds; we also present an improved upper bound for on-line coloring.