Title
The surviving rate of digraphs
Abstract
Let [email protected]? be a connected digraph with n>=2 vertices. Suppose that a fire breaks out at a vertex v of [email protected]?. A firefighter starts to protect vertices. At each time interval, the firefighter protects k vertices not yet on fire. Afterward, the fire spreads to all unprotected neighbors that are heads of some arcs starting from the vertices on fire. Let sn"k(v) denote the maximum number of vertices in [email protected]? that the firefighter can save when a fire breaks out at vertex v. The k-surviving rate @r"k([email protected]?) of [email protected]? is defined as @?"v"@?"V"("G"@?")sn"k(v)/n^2. In this paper, we consider the k-surviving rate of digraphs. Main results are as follows: (1) if [email protected]? is a k-degenerate digraph, then @r"k([email protected]?)>=1k+1; (2) if [email protected]? is a planar digraph, then @r"2([email protected]?)>140; (3) if [email protected]? is a planar digraph without 4-cycles, then @r"1([email protected]?)>151.
Year
DOI
Venue
2014
10.1016/j.disc.2014.06.018
Discrete Mathematics
Keywords
Field
DocType
firefighter problem,surviving rate,planar graph,discharging,digraph
Discrete mathematics,Combinatorics,Vertex (geometry),Planar graph,Digraph,Mathematics
Journal
Volume
Issue
ISSN
334
1
0012-365X
Citations 
PageRank 
References 
6
0.57
12
Authors
3
Name
Order
Citations
PageRank
Jiangxu Kong1323.41
Lian-Zhu Zhang2339.04
Weifan Wang386889.92