Title
Exact Algorithms for (2,1)-Labeling of Graphs
Abstract
The notion of distance constrained graph labelings, motivated by the Frequency Assignment Problem, reads as follows: A mapping from the vertex set of a graph G=(V,E) into an interval of integers {0,…,k} is an L(2,1)-labeling of G of span k if any two adjacent vertices are mapped onto integers that are at least 2 apart, and every two vertices with a common neighbor are mapped onto distinct integers. It is known that for any fixed k≥4, deciding the existence of such a labeling is an NP-complete problem. We present exact exponential time algorithms that are faster than the naive O *((k+1)n ) algorithm that would try all possible mappings. The improvement is best seen in the first NP-complete case of k=4, where the running time of our algorithm is O(1.3006n ). Furthermore we show that dynamic programming can be used to establish an O(3.8730n ) algorithm to compute an optimal L(2,1)-labeling.
Year
DOI
Venue
2011
https://doi.org/10.1007/s00453-009-9302-7
Algorithmica
Keywords
Field
DocType
Graph,Algorithm,Moderately exponential time algorithm,L,(2,1)-labeling
Frequency assignment problem,Integer,Dynamic programming,Discrete mathematics,Graph,NP-complete,Combinatorics,Exponential function,Vertex (geometry),Vertex (graph theory),Algorithm,Mathematics
Journal
Volume
Issue
ISSN
59
2
0178-4617
Citations 
PageRank 
References 
20
1.02
18
Authors
5
Name
Order
Citations
PageRank
Frédéric Havet143355.15
Martin Klazar228231.64
Jan Kratochvíl31751151.84
Dieter Kratsch41957146.89
Mathieu Liedloff524324.23