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Tetravex is a widely played one person computer game in which you are given $n^2$ unit tiles, each edge of which is labelled with a number. The objective is to place each tile within a $n$ by $n$ square such that all neighbouring edges are…

Computational Complexity · Computer Science 2012-04-18 Yasuhiko Takenaga , Toby Walsh

We prove the computational intractability of rotating and placing $n$ square tiles into a $1 \times n$ array such that adjacent tiles are compatible--either equal edge colors, as in edge-matching puzzles, or matching tab/pocket shapes, as…

Computational Complexity · Computer Science 2017-01-03 Jeffrey Bosboom , Erik D. Demaine , Martin L. Demaine , Adam Hesterberg , Pasin Manurangsi , Anak Yodpinyanee

We present a new game, Dots & Polygons, played on a planar point set. Players take turns connecting two points, and when a player closes a (simple) polygon, the player scores its area. We show that deciding whether the game can be won from…

Computational Geometry · Computer Science 2020-05-27 Kevin Buchin , Mart Hagedoorn , Irina Kostitsyna , Max van Mulken , Jolan Rensen , Leo van Schooten

This work shows new results on the complexity of games Jelly-No and Hanano with various constraints on the size of the board and number of colours. Hanano and Jelly-No are one-player, 2D side-view puzzle games with a dynamic board…

Computational Complexity · Computer Science 2026-04-14 Owen Crabtree , Valia Mitsou

Minesweeper is an interesting single player game based on logic, memory and guessing. Solving Minesweeper has been shown to be an NP-hard task. Deterministic solvers are the best known approach for solving Minesweeper. This project proposes…

Artificial Intelligence · Computer Science 2022-12-21 M Hamza Sajjad

Motivated by understanding non-strict and strict pure strategy equilibria in network anti-coordination games, we define notions of stable and, respectively, strictly stable colorings in graphs. We characterize the cases when such colorings…

Computer Science and Game Theory · Computer Science 2013-08-16 Jeremy Kun , Brian Powers , Lev Reyzin

LR(1) parsing was a focus of extensive research in the past 50 years. Though most fundamental mysteries have been resolved, a few remain hidden in the dark corners. The one we bumped into is the minimization of the LR(1) state machines,…

Computation and Language · Computer Science 2021-10-05 Wuu Yang

We analyze the computational complexity of solving the three "temporal rift" puzzles in the recent popular video game Final Fantasy XIII-2. We show that the Tile Trial puzzle is NP-hard and we provide an efficient algorithm for solving the…

Computational Complexity · Computer Science 2012-03-09 Nathaniel Johnston

We present a new problem called the incomplete Traveling Tournament problem, which introduces the well known Traveling Tournament Problem into the realm of incomplete round-robin tournaments. We focus on the case where teams can face each…

Optimization and Control · Mathematics 2026-03-23 Karel Devriesere , David Van Bulck , Dries Goossens

Ridge Rider (RR) is an algorithm for finding diverse solutions to optimization problems by following eigenvectors of the Hessian ("ridges"). RR is designed for conservative gradient systems (i.e., settings involving a single loss function),…

Computer Science and Game Theory · Computer Science 2021-12-30 Jonathan Lorraine , Paul Vicol , Jack Parker-Holder , Tal Kachman , Luke Metz , Jakob Foerster

We classify the computational complexity of the popular video games Portal and Portal 2. We isolate individual mechanics of the game and prove NP-hardness, PSPACE-completeness, or (pseudo)polynomiality depending on the specific game…

Computational Complexity · Computer Science 2016-12-01 Erik D. Demaine , Joshua Lockhart , Jayson Lynch

We study a popular puzzle game known variously as Clickomania and Same Game. Basically, a rectangular grid of blocks is initially colored with some number of colors, and the player repeatedly removes a chosen connected monochromatic group…

Computational Complexity · Computer Science 2007-05-23 Therese C. Biedl , Erik D. Demaine , Martin L. Demaine , Rudolf Fleischer , Lars Jacobsen , J. Ian Munro

Creating robots that can perform general-purpose service tasks in a human-populated environment has been a longstanding grand challenge for AI and Robotics research. One particularly valuable skill that is relevant to a wide variety of…

Robotics · Computer Science 2021-03-31 Harel Yedidsion , Jennifer Suriadinata , Zifan Xu , Stefan Debruyn , Peter Stone

We prove that a particular pushing-blocks puzzle is intractable in 2D, improving an earlier result that established intractability in 3D [OS99]. The puzzle, inspired by the game *PushPush*, consists of unit square blocks on an integer…

Computational Geometry · Computer Science 2007-05-23 Erik D. Demaine , Martin L. Demaine , Joseph O'Rourke

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…

Computational Complexity · Computer Science 2007-05-23 Erik D. Demaine , Susan Hohenberger , David Liben-Nowell

This paper introduces the Packing While Traveling problem as a new non-linear knapsack problem. Given are a set of cities that have a set of items of distinct profits and weights and a vehicle that may collect the items when visiting all…

Data Structures and Algorithms · Computer Science 2017-03-22 Sergey Polyakovskiy , Frank Neumann

We study three problems related to the computational complexity of the popular game Minesweeper. The first is consistency: given a set of clues, is there any arrangement of mines that satisfies it? This problem has been known to be…

Computational Complexity · Computer Science 2024-04-24 MIT Hardness Group , Della Hendrickson , Andy Tockman

Building on the results published in arxiv:2004.12849 we present a general framework for demonstrating the NP-hardness of satisfying many genres of loop and path puzzles using a 'T-metacell' gadget. We then use this to prove the…

Computational Complexity · Computer Science 2022-02-07 Hadyn Tang

Designing Public Transport (PT) networks able to satisfy mobility needs of people is essential to reduce the number of individual vehicles on the road, and thus pollution and congestion. Urban sustainability is thus tightly coupled to an…

Artificial Intelligence · Computer Science 2024-10-14 Duo Wang , Maximilien Chau , Andrea Araldo

Recently, Dohrau et al. studied a zero-player game on switch graphs and proved that deciding the termination of the game is in NP $\cap$ coNP. In this short paper, we show that the search version of this game on switch graphs, i.e., the…

Computational Complexity · Computer Science 2017-01-09 Karthik C. S.