P-complete

Acyclic Geography Game (AGG)

Category: Games

Input

An acyclic directed graph $G = (V, E)$.

Problem

Does player one have a winning strategy on $G$?

Description

The Acyclic Geography Game is played on $G$ by two players. A configuration of the game is a vertex $u \in V$. Players take turns choosing an edge $(u, v) \in G$, thereby changing the game configuration from $u$ to $v$. The initial configuration is $u = 1$. The first player with no move left loses.

Status

$\P$-complete (Chandra and Tompa [1]).

Remarks

The reduction to show hardness is from MCVP. Chandra and Tompa show that a depth constrained version of the Geography Game, called SHORTGEOG, is complete for $\mathsf{AC}^1$ [1].

References

  1. A. K. Chandra and M. Tompa (1990). The complexity of short two-person games.
  2. Greenlaw, R., Hoover, H. J., and Ruzzo, W. L. (1995). Limits to Parallel Computation: P-Completeness Theory. Oxford University Press. Problem A.11.3.