Digraphs of bounded elimination width
نویسندگان
چکیده
منابع مشابه
Digraphs of bounded elimination width
Hunter and Kreutzer recently introduced the digraph width measure Kelly-width. The measure is based on a vertex elimination process that aims at bounding the out-degree of a vertex during the elimination. We refine the Kelly-width measure by bounding both the out-degree and the in-degree of a vertex. We show that the elimination process and a subgraph characterisation of Kelly-width naturally g...
متن کاملCharacterization and Recognition of Digraphs of Bounded Kelly-width
Kelly-width is a parameter of directed graphs recently proposed by Hunter and Kreutzer as a directed analogue of treewidth. We give several alternative characterizations of directed graphs of bounded Kelly-width in support of this analogy. We apply these results to give the first polynomial-time algorithm recognizing directed graphs of Kelly-width 2. For an input directed graph G = (V,A) the al...
متن کاملMulticuts in unweighted graphs and digraphs with bounded degree and bounded tree-width
CNRS Paris, France and Department of Computer Science E-mail: [email protected] The Multicut problem can be defined as: given a graph G and a collection of pairs of distinct vertices fsi; tig ofG, find a minimum set of edges ofGwhose removal disconnects each si from the corresponding ti. Multicut is known to be NP-hard and Max SNP-hard even when the input graph is restricted to being a tree. ...
متن کاملOn the complexity of the multicut problem in bounded tree-width graphs and digraphs
Given an edgeor vertex-weighted graph or digraph and a list of source-sink pairs, the minimum multicut problem consists in selecting a minimum weight set of edges or vertices whose removal leaves no path from each source to the corresponding sink. This is a classical NPhard problem, and we show that the edge version becomes tractable in bounded tree-width graphs if the number of source-sink pai...
متن کاملDAG-width and circumference of digraphs
We prove that every digraph of circumference l has DAG-width at most l and this is best possible. As a consequence of our result we deduce that the k-linkage problem is polynomially solvable for every fixed k in the class of digraphs with bounded circumference. This answers a question posed in [2]. We also prove that the weak k-linkage problem (where we ask for arc-disjoint paths) is polynomial...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Discrete Applied Mathematics
سال: 2014
ISSN: 0166-218X
DOI: 10.1016/j.dam.2013.05.005