Does the lit-only restriction make any difference for the σ-game and σ+-game?

  • Authors:
  • John Goldwasser;Xinmao Wang;Yaokun Wu

  • Affiliations:
  • Department of Mathematics, West Virginia University, Morgantown, WV 26506, United States;Department of Mathematics, University of Science and Technology of China, Hefei, 230026, China;Department of Mathematics, Shanghai Jiao Tong University, Shanghai, 200240, China

  • Venue:
  • European Journal of Combinatorics
  • Year:
  • 2009

Quantified Score

Hi-index 0.00

Visualization

Abstract

Each vertex in a simple graph is in one of two states: "on" or "off". The set of all on vertices is called a configuration. In the σ-game, "pushing" a vertex v changes the state of all vertices in the open neighborhood of v, while in the σ+-game pushing v changes the state of all vertices in its closed neighborhood. The reachability question for these two games is to decide whether a given configuration can be reached from a given starting configuration by a sequence of pushes. We consider the lit-only restriction on these two games where a vertex can be pushed only if it is in the on state. We show that the lit-only restriction can make a big difference for reachability in the σ-game, but has essentially no effect in the σ+-game.