Labeling cacti with a condition at distance two

Authors

  • S. K. Vaidya Saurashtra University
  • D. D. Bantva Atmiya Institute of Technology and Science, Rajkot - 360 005

Keywords:

L(2, 1)-labeling, λ-number, Cactus graph, Block cut point graph, One point union of cycles

Abstract

 

An L(2,1)-labeling of a graph G is a function f  from the vertex set V(G) to the set of all nonnegative integers such that | f (x)- f (y)| ≥ 2 if d(x, y) = 1 and | f (x) - f (y)| ≥ 1 if d(x, y) = 2. The L(2,1)-labeling number λ(G) of G is the smallest number k such that G has an L(2,1)-labeling with max{f (v) : v Î V(G)} = k. In this paper we present a graph family which has λ-number Δ+1 or Δ+2.

Author Biographies

  • S. K. Vaidya, Saurashtra University

    Associate Professor

    Department of Mathematics

    Saurashtra University

    Rajkot-360005

    Gujarat(India)
  • D. D. Bantva, Atmiya Institute of Technology and Science, Rajkot - 360 005

    Assistant Professor

    Department of Mathematics

    Atmiya Institute of Technology and Science

    Rajkot - 360005

    Gujarat(India)

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Published

2011-06-27

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Section

Articoli