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On indicated coloring of some classes of graphs

Combinatorics 2018-02-02 v1

Abstract

Indicated coloring is a type of game coloring in which two players collectively color the vertices of a graph in the following way. In each round the first player (Ann) selects a vertex, and then the second player (Ben) colors it properly, using a fixed set of colors. The goal of Ann is to achieve a proper coloring of the whole graph, while Ben is trying to prevent the realization of this project. The smallest number of colors necessary for Ann to win the game on a graph GG (regardless of Ben's strategy) is called the indicated chromatic number of GG, denoted by χi(G)\chi_i(G). In this paper, we obtain structural characterization of connected {P5,K4,Kite,Bull}\{P_5,K_4,Kite,Bull\}-free graphs which contains an induced C5C_5 and connected {P6,C5,K1,3}\{P_6,C_5, K_{1,3}\}-free graphs that contains an induced C6C_6. Also, we prove that {P5,K4,Kite,Bull}\{P_5,K_4,Kite,Bull\}-free graphs that contains an induced C5C_5 and {P6,C5,P5,K1,3}\{P_6,C_5,\overline{P_5}, K_{1,3}\}-free graphs which contains an induced C6C_6 are kk-indicated colorable for all kχ(G)k\geq\chi(G). In addition, we show that K[C5]\mathbb{K}[C_5] is kk-indicated colorable for all kχ(G)k\geq\chi(G) and as a consequence, we exhibit that {P2P3,C4}\{P_2\cup P_3, C_4\}-free graphs, {P5,C4}\{P_5,C_4\}-free graphs are kk-indicated colorable for all kχ(G)k\geq\chi(G). This partially answers one of the questions which was raised by A. Grzesik in \cite{and}.

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Cite

@article{arxiv.1802.00251,
  title  = {On indicated coloring of some classes of graphs},
  author = {P. Francis and S. Francis Raj and M. Gokulnath},
  journal= {arXiv preprint arXiv:1802.00251},
  year   = {2018}
}

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19 Pages