no code implementations • 11 Mar 2021 • Oswin Aichholzer, Erik D. Demaine, Matias Korman, Jayson Lynch, Anna Lubiw, Zuzana Mas, Mikhail Rudoy, Virginia Vassilevska Williams, Nicole Wein
We also show limitations on approximation of sequential token swapping on trees: we identify a broad class of algorithms that encompass all three known polynomial-time algorithms that achieve the best known approximation factor (which is $2$) and show that no such algorithm can achieve an approximation factor less than $2$.
Motion Planning Data Structures and Algorithms Computational Complexity
1 code implementation • 22 Mar 2020 • Josh Brunner, Lily Chung, Erik D. Demaine, Dylan Hendrickson, Adam Hesterberg, Adam Suhl, Avi Zeff
Consider $n^2-1$ unit-square blocks in an $n \times n$ square board, where each block is labeled as movable horizontally (only), movable vertically (only), or immovable -- a variation of Rush Hour with only $1 \times 1$ cars and fixed blocks.
Computational Complexity Computational Geometry
1 code implementation • 26 Apr 2018 • Zachary Abel, Jeffrey Bosboom, Michael Coulombe, Erik D. Demaine, Linus Hamilton, Adam Hesterberg, Justin Kopinsky, Jayson Lynch, Mikhail Rudoy, Clemens Thielen
We analyze the computational complexity of the many types of pencil-and-paper-style puzzles featured in the 2016 puzzle video game The Witness.
Computational Complexity
no code implementations • 3 Mar 2018 • Jin Akiyama, Erik D. Demaine, Stefan Langerman
We prove that two polygons $A$ and $B$ have a reversible hinged dissection (a chain hinged dissection that reverses inside and outside boundaries when folding between $A$ and $B$) if and only if $A$ and $B$ are two noncrossing nets of a common polyhedron.
Computational Geometry Metric Geometry
no code implementations • 21 Jun 2017 • Erik D. Demaine, Sarah Eisenstat, Mikhail Rudoy
In this paper, we prove that optimally solving an $n \times n \times n$ Rubik's Cube is NP-complete by reducing from the Hamiltonian Cycle problem in square grid graphs.
Computational Complexity Computational Geometry Combinatorics F.1.3
no code implementations • 10 Jun 2014 • Erik D. Demaine, Felix Reidl, Peter Rossmanith, Fernando Sanchez Villaamil, Somnath Sikdar, Blair D. Sullivan
This research establishes that many real-world networks exhibit bounded expansion, a strong notion of structural sparsity, and demonstrates that it can be leveraged to design efficient algorithms for network analysis.
Social and Information Networks Discrete Mathematics Data Structures and Algorithms Physics and Society
no code implementations • 15 Mar 2010 • Erik D. Demaine, Martin L. Demaine, Nicholas J. A. Harvey, Ryuhei Uehara, Takeaki Uno, Yushi Uno
This paper investigates the popular card game UNO from the viewpoint of algorithmic combinatorial game theory.
Discrete Mathematics Computational Complexity G.2; F.1
2 code implementations • 21 Oct 2002 • Erik D. Demaine, Susan Hohenberger, David Liben-Nowell
In the popular computer game of Tetris, the player is given a sequence of tetromino pieces and must pack them into a rectangular gameboard initially occupied by a given configuration of filled squares; any completely filled row of the gameboard is cleared and all pieces above it drop by one row.
Computational Complexity Computational Geometry Discrete Mathematics F.1.3; F.2.2; G.2.1; K.8.0