id: 06044345 dt: a an: 06044345 au: Forišek, Michal; Keller, Lucia; Steinová, Monika ti: Advice complexity of online coloring for paths. so: Dediu, Adrian-Horia (ed.) et al., Language and automata theory and applications. 6th international conference, LATA 2012, A Coruña, Spain, March 5‒9, 2012. Proceedings. Berlin: Springer (ISBN 978-3-642-28331-4/pbk). Lecture Notes in Computer Science 7183, 228-239 (2012). py: 2012 pu: Berlin: Springer la: EN cc: ut: Advice Complexity; Online Graph Coloring; Partial Coloring ci: li: doi:10.1007/978-3-642-28332-1_20 ab: Summary: In online graph coloring a graph is revealed to an online algorithm one vertex at a time, and the algorithm must color the vertices as they appear. This paper starts to investigate the advice complexity of this problem ‒ the amount of oracle information an online algorithm needs in order to make optimal choices. We also consider a more general problem ‒ a trade-off between online and offline graph coloring. In the paper we prove that precisely $\lceil n/2 \rceil - 1$ bits of advice are needed when the vertices on a path are presented for coloring in arbitrary order. The same holds in the more general case when just a subset of the vertices is colored online. However, the problem turns out to be non-trivial for the case where the online algorithm is guaranteed that the vertices it receives form a subset of a path and are presented in the order in which they lie on the path. For this variant we prove that its advice complexity is $βn + O(\log n)$ bits, where $β\approx 0.406$ is a fixed constant (we give its closed form). This suggests that the generalized problem will be challenging for more complex graph classes. rv: