18 research outputs found
Asymmetric coloring games on incomparability graphs
Consider the following game on a graph : Alice and Bob take turns coloring
the vertices of properly from a fixed set of colors; Alice wins when the
entire graph has been colored, while Bob wins when some uncolored vertices have
been left. The game chromatic number of is the minimum number of colors
that allows Alice to win the game. The game Grundy number of is defined
similarly except that the players color the vertices according to the first-fit
rule and they only decide on the order in which it is applied. The -game
chromatic and Grundy numbers are defined likewise except that Alice colors
vertices and Bob colors vertices in each round. We study the behavior of
these parameters for incomparability graphs of posets with bounded width. We
conjecture a complete characterization of the pairs for which the
-game chromatic and Grundy numbers are bounded in terms of the width of
the poset; we prove that it gives a necessary condition and provide some
evidence for its sufficiency. We also show that the game chromatic number is
not bounded in terms of the Grundy number, which answers a question of Havet
and Zhu
The Relaxed Game Chromatic Index of \u3cem\u3ek\u3c/em\u3e-Degenerate Graphs
The (r, d)-relaxed coloring game is a two-player game played on the vertex set of a graph G. We consider a natural analogue to this game on the edge set of G called the (r, d)-relaxed edge-coloring game. We consider this game on trees and more generally, on k-degenerate graphs. We show that if G is k-degenerate with ∆(G) = ∆, then the first player, Alice, has a winning strategy for this game with r = ∆+k−1 and d≥2k2 + 4k
The Relaxed Edge-Coloring Game and \u3cem\u3ek\u3c/em\u3e-Degenerate Graphs
The (r, d)-relaxed edge-coloring game is a two-player game using r colors played on the edge set of a graph G. We consider this game on forests and more generally, on k-degenerate graphs. If F is a forest with ∆(F) = ∆, then the first player, Alice, has a winning strategy for this game with r = ∆ − j and d ≥ 2j + 2 for 0 ≤ j ≤ ∆ − 1. This both improves and generalizes the result for trees in [10]. More broadly, we generalize the main result in [10] by showing that if G is k-degenerate with ∆(G) = ∆ and j ∈ [∆ + k − 1], then there exists a function h(k, j) such that Alice has a winning strategy for this game with r = ∆ + k − j and d ≥ h(k, j)
Game Chromatic Number of Shackle Graphs
Coloring vertices on graph is one of the topics of discrete mathematics that are still developing until now. Exploration Coloring vertices develops in the form of a game known as a coloring game. Let G graph. The smallest number k such that the graph G can be colored in a coloring game is called game chromatic number. Notated as χ_g (G). The main objective of this research is to prove game chromatic numbers from graphsThis study examines and proves game chromatic numbers from graphs shack(K_n,v_i,t),shack(S_n,v_i,t), and shack(K_(n,n),v_i,t). The research method used in this research is qualitative. The result show that χ_g (shack(K_n,v_i,t))=n,and χ_g (shack(S_n,v_i,t))=χ_g (shack(K_(n,n),v_i,t))=3. The game chromatic number of the shackle graph depends on the subgraph and linkage vertices. Therefore, it is necessary to make sure the vertex linkage is colored first
The Game Chromatic Number of Complete Multipartite Graphs with No Singletons
In this paper we investigate the game chromatic number for complete
multipartite graphs. We devise several strategies for Alice, and one strategy
for Bob, and we prove their optimality in all complete multipartite graphs with
no singletons. All the strategies presented are computable in linear time, and
the values of the game chromatic number depend directly only on the number and
the sizes of sets in the partition
On characterizing game-perfect graphs by forbidden induced subgraphs
A graph is called -perfect if, for any induced subgraph of , the game chromatic number of equals the clique number of . A graph is called -col-perfect if, for any induced subgraph of , the game coloring number of equals the clique number of . In this paper we characterize the classes of -perfect resp. -col-perfect graphs by a set of forbidden induced subgraphs and explicitly. Moreover, we study similar notions for variants of the game chromatic number, namely -perfect and -perfect graphs, and for several variants of the game coloring number, and characterize the classes of these graphs