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arXiv · 1302.3811

Indicated coloring of matroids

Michał Lasoń
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Abstract

A coloring of a matroid is proper if elements of the same color form an independent set. For a loopless matroid M, its chromatic number χ(M) is the minimum number of colors that suffices to color properly the ground set E of M. In this note we study a game-theoretic variant of this parameter proposed by Grytczuk. Suppose that in each round of the game Alice indicates an uncolored yet element e of E, then Bob colors it using a color from a fixed set of colors C. The rule Bob has to obey is that it is a proper coloring. The game ends if the whole matroid has been colored or if Bob can not color e using any color of C. Alice wins in the first case, while Bob in the second. The minimum size of the set of colors C for which Alice has a winning strategy is called the indicated chromatic number of M, denoted by χ_i(M). We prove that χ_i(M)=χ(M).

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Michał Lasoń. 2013-02-15. Indicated coloring of matroids. https://doi.org/10.1016/j.dam.2014.07.004

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