k-Chordal Graphs: from Cops and Robber to Compact Routing via Treewidth
KOSOWSKI, Adrian
Algorithmics for computationally intensive applications over wide scale distributed platforms [CEPAGE]
Laboratoire Bordelais de Recherche en Informatique [LaBRI]
Algorithmics for computationally intensive applications over wide scale distributed platforms [CEPAGE]
Laboratoire Bordelais de Recherche en Informatique [LaBRI]
NISSE, Nicolas
Algorithms, simulation, combinatorics and optimization for telecommunications [MASCOTTE]
Leer más >
Algorithms, simulation, combinatorics and optimization for telecommunications [MASCOTTE]
KOSOWSKI, Adrian
Algorithmics for computationally intensive applications over wide scale distributed platforms [CEPAGE]
Laboratoire Bordelais de Recherche en Informatique [LaBRI]
Algorithmics for computationally intensive applications over wide scale distributed platforms [CEPAGE]
Laboratoire Bordelais de Recherche en Informatique [LaBRI]
NISSE, Nicolas
Algorithms, simulation, combinatorics and optimization for telecommunications [MASCOTTE]
< Leer menos
Algorithms, simulation, combinatorics and optimization for telecommunications [MASCOTTE]
Idioma
en
Rapport
Este ítem está publicado en
2012-02
Resumen en inglés
{\it Cops and robber games} concern a team of cops that must capture a robber moving in a graph. We consider the class of $k$-chordal graphs, i.e., graphs with no induced cycle of length greater than $k$, $k\geq 3$. We ...Leer más >
{\it Cops and robber games} concern a team of cops that must capture a robber moving in a graph. We consider the class of $k$-chordal graphs, i.e., graphs with no induced cycle of length greater than $k$, $k\geq 3$. We prove that $k-1$ cops are always sufficient to capture a robber in $k$-chordal graphs. This leads us to our main result, a new structural decomposition for a graph class including $k$-chordal graphs. We present a quadratic algorithm that, given a graph $G$ and $k\geq 3$, either returns an induced cycle larger than $k$ in $G$, or computes a {\it tree-decomposition} of $G$, each {\it bag} of which contains a dominating path with at most $k-1$ vertices. This allows us to prove that any $k$-chordal graph with maximum degree $\Delta$ has treewidth at most $(k-1)(\Delta-1)+2$, improving the $O(\Delta (\Delta-1)^{k-3})$ bound of Bodlaender and Thilikos (1997). Moreover, any graph admitting such a tree-decomposition has hyperbolicity $\leq\lfloor \frac{3}{2}k\rfloor$. As an application, for any $n$-node graph admitting such a tree-decomposition, we propose a {\it compact routing scheme} using routing tables, addresses and headers of size $O(\log n)$ bits and achieving an additive stretch of $O(k\log \Delta)$. As far as we know, this is the first routing scheme with $O(\log n)$-routing tables and small additive stretch for $k$-chordal graphs.< Leer menos
Palabras clave en inglés
Treewidth
chordality
hyperbolicity
compact routing
cops and robber games
Proyecto europeo
Experimental UpdateLess Evolutive Routing
Proyecto ANR
Algorithmes de graphes parametres et exacts - ANR-09-BLAN-0159
Orígen
Importado de HalCentros de investigación