A Simple Proof that Ricochet Robots is PSPACE-Complete

Jose Balanza-Martinez; Angel A. Cantu; Robert Schweller; Tim Wylie

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arXiv · 2402.11440

A Simple Proof that Ricochet Robots is PSPACE-Complete

Jose Balanza-Martinez·Angel A. Cantu·Robert Schweller·Tim Wylie

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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.

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Jose Balanza-Martinez, Angel A. Cantu, Robert Schweller, Tim Wylie. 2024-02-18. A Simple Proof that Ricochet Robots is PSPACE-Complete. https://arxiv.org/abs/2402.11440

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