English

A Simple Proof that Ricochet Robots is PSPACE-Complete

Computational Complexity 2024-02-20 v1 Data Structures and Algorithms

Abstract

In this paper, we seek to provide a simpler proof that the relocation problem in Ricochet Robots (Lunar Lockout with fixed geometry) is PSPACE-complete via a reduction from Finite Function Generation (FFG). Although this result was originally proven in 2003, we give a simpler reduction by utilizing the FFG problem, and put the result in context with recent publications showing that relocation is also PSPACE-complete in related models.

Cite

@article{arxiv.2402.11440,
  title  = {A Simple Proof that Ricochet Robots is PSPACE-Complete},
  author = {Jose Balanza-Martinez and Angel A. Cantu and Robert Schweller and Tim Wylie},
  journal= {arXiv preprint arXiv:2402.11440},
  year   = {2024}
}
R2 v1 2026-06-28T14:52:04.418Z