Directed Path-width and Monotonicity in Digraph Searching
نویسندگان
چکیده
منابع مشابه
Directed Path-width and Monotonicity in Digraph Searching
Directed path-width was defined by Reed, Thomas and Seymour around 1995. The author and P. Hajnal defined a cops-and-robber game on digraphs in 2000. We prove that the two notions are closely related and for any digraph D, the corresponding graph parameters differ by at most one. The result is achieved using the mixed-search technique developed by Bienstock and Seymour. A search is called monot...
متن کاملDigraph Decompositions and Monotonicity in Digraph Searching
We consider monotonicity problems for graph searching games. Variants of these games – defined by the type of moves allowed for the players – have been found to be closely connected to graph decompositions and associated width measures such as pathor tree-width. Of particular interest is the question whether these games are monotone, i.e. whether the cops can catch a robber without ever allowin...
متن کاملDirected Width Measures and Monotonicity of Directed Graph Searching
We consider generalisations of tree width to directed graphs, that attracted much attention in the last fifteen years. About their relative strength with respect to “bounded width in one measure implies bounded width in the other” many problems remain unsolved. Only some results separating directed width measures are known. We give an almost complete picture of this relation. For this, we consi...
متن کاملDirected Searching Digraphs: Monotonicity and Complexity
In this paper, we introduce and study two new search models on digraphs: the directed searching and mixed directed searching. In these two search models, both searchers and intruders must follow the edge directions when they move along edges. We prove the monotonicity of both search models, and we show that both directed and mixed directed search problems are NP-complete.
متن کاملGraph Searching Games and Width Measures for Directed Graphs
In cops and robber games a number of cops tries to capture a robber in a graph. A variant of these games on undirected graphs characterises tree width by the least number of cops needed to win. We consider cops and robber games on digraphs and width measures (such as DAG-width, directed tree width or D-width) corresponding to them. All of them generalise tree width and the game characterising i...
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: Graphs and Combinatorics
سال: 2006
ISSN: 0911-0119,1435-5914
DOI: 10.1007/s00373-005-0627-y