Title
Two Conjectures on Graceful Digraphs
Abstract
digraph D with p vertices and q arcs is labeled by assigning a distinct integer value g ( v ) from {0,1, , q } to each vertex v . The vertex values, in turn, induce a value g ( u, v ) on each arc ( u, v ) where g ( u, v ) = ( g ( v ) g ( u ))( mod q + 1). If the arc values are all distinct then the labeling is called a graceful labeling of a digraph. Bloom and Hsu (SIAM J Alg Discr Methods 6:519---536, 1985 ) conjectured that, all unicyclic wheels are graceful. Also, Zhao et al. (J Prime Res Math 4:118---126, 2008 ) conjectured that, for any positive even n and any integer m 14, the digraph $${n-\overrightarrow{C_m}}$$ is graceful. In this paper, we prove both the conjectures.
Year
DOI
Venue
2013
10.1007/s00373-012-1159-x
Graphs and Combinatorics
Keywords
Field
DocType
generating functions,graceful digraphs,partitions,unicyclic wheels
Prime (order theory),Integer,Generating function,Discrete mathematics,Combinatorics,Vertex (geometry),Graceful labeling,Mathematics,Digraph
Journal
Volume
Issue
ISSN
29
4
1435-5914
Citations 
PageRank 
References 
1
0.48
0
Authors
2
Name
Order
Citations
PageRank
S. M. Hegde1329.96
Shivarajkumar210.82