Publications (9)
Infinite All-Layers Simple Foldability
Hugo A. Akitaya, Cordelia Avery, Joseph Bergeron +3
We study the problem of deciding whether a crease pattern can be folded by simple folds (folding along one line at a time) under the infinite all-layers model introduced by [Akitay…
Recursed is not Recursive: A Jarring Result
Erik Demaine, Justin Kopinsky, Jayson Lynch
Recursed is a 2D puzzle platform video game featuring treasure chests that, when jumped into, instantiate a room that can later be exited (similar to function calls), optionally ge…
Path Puzzles: Discrete Tomography with a Path Constraint is Hard
Jeffrey Bosboom, Erik D. Demaine, Martin L. Demaine +3
We prove that path puzzles with complete row and column information--or equivalently, 2D orthogonal discrete tomography with Hamiltonicity constraint--are strongly NP-complete, ASP…
Relaxed Schedulers Can Efficiently Parallelize Iterative Algorithms
Dan Alistarh, Trevor Brown, Justin Kopinsky +1
There has been significant progress in understanding the parallelism inherent to iterative sequential algorithms: for many classic algorithms, the depth of the dependence structure…
Who witnesses The Witness? Finding witnesses in The Witness is hard and sometimes impossible
Zachary Abel, Jeffrey Bosboom, Michael Coulombe +7
We analyze the computational complexity of the many types of pencil-and-paper-style puzzles featured in the 2016 puzzle video game The Witness. In all puzzles, the goal is to draw…
The LevelArray: A Fast, Practical Long-Lived Renaming Algorithm
Dan Alistarh, Justin Kopinsky, Alexander Matveev +1
The long-lived renaming problem appears in shared-memory systems where a set of threads need to register and deregister frequently from the computation, while concurrent operations…