Title
Fighting constrained fires in graphs
Abstract
The firefighter problem is a simplified model for the spread of a fire (or disease or computer virus) in a network. A fire breaks out at a vertex in a connected graph, and spreads to each of its unprotected neighbours over discrete time-steps. A firefighter protects one vertex in each round which is not yet burned. While maximizing the number of saved vertices usually requires a strategy on the part of the firefighter, the fire itself spreads without any strategy. We consider a variant of the problem where the fire is constrained by spreading to a fixed number of vertices in each round. In the two-player game of k-firefighter, for a fixed positive integer k, the fire chooses to burn at most k unprotected neighbours in a given round. The k-surviving rate of a graph G is defined as the expected percentage of vertices that can be saved in k-firefighter when a fire breaks out at a random vertex of G. We supply bounds on the k-surviving rate, and determine its value for families of graphs including wheels and prisms. We show using spectral techniques that random d regular graphs have k-surviving rate at most (1+O(d^-^1^/^2))k+1. We consider the limiting surviving rate for countably infinite graphs. In particular, we show that the limiting surviving rate of the infinite random graph can be any real number in [1/(k+1),1].
Year
DOI
Venue
2012
10.1016/j.tcs.2012.01.041
Theor. Comput. Sci.
Keywords
DocType
Volume
real number,firefighter problem,k-surviving rate,regular graph,random vertex,connected graph,graph G,fixed number,countably infinite graph,infinite random graph
Journal
434,
ISSN
Citations 
PageRank 
0304-3975
0
0.34
References 
Authors
6
3
Name
Order
Citations
PageRank
Anthony Bonato115618.57
Margaret-Ellen Messinger2639.83
Pawe Praat3272.84