12 papers
Pushing Blocks without Fixed Walls via Checkable Gizmos: Push-1 is PSPACE-Complete
MIT Hardness Group, Josh Brunner, Lily Chung +4
We prove PSPACE-completeness of Push-1: given a rectangular grid of 1 x 1 cells, each possibly occupied by a movable block, can a robot move from one specified location to another,…
Walking through Doors is Hard, even without Staircases: Universality and PSPACE-hardness of Planar Door Gadgets
MIT Gadgets Group, Jeffrey Bosboom, Erik D. Demaine +4
An open-close door gadget has two states and three tunnels that can be traversed by an agent (player, robot, etc.): the "opening" and "closing" tunnels set the gadget's state to op…
All Polyhedral Manifolds are Connected by a 2-Step Refolding
Lily Chung, Erik D. Demaine, Jenny Diomidova +4
We prove that, for any two polyhedral manifolds , there is a polyhedral manifold such that share a common unfolding and…
Who Needs Crossings?: Noncrossing Linkages are Universal, and Deciding (Global) Rigidity is Hard
Zachary Abel, Erik D. Demaine, Martin L. Demaine +3
We exactly settle the complexity of graph realization, graph rigidity, and graph global rigidity as applied to three types of graphs: "globally noncrossing" graphs, which avoid cro…
Escaping a Polygon
Zachary Abel, Hugo Akitaya, Erik D. Demaine +4
Suppose an escaping player ("human") moves continuously at maximum speed in the interior of a region, while a pursuing player ("zombie") moves continuously at maximum speed …
All Polyhedral Manifolds are Connected by a 2-Step Refolding
Lily Chung, Erik D. Demaine, Jenny Diomidova +4
We prove that, for any two polyhedral manifolds , there is a polyhedral manifold such that share a common unfolding an…