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We provide a winning strategy for sums of games of MARK-t, an impartial game played on the nonnegative integers where each move consists of subtraction by an integer between 1 and t-1 inclusive, or division by t, rounding down when…

Combinatorics · Mathematics 2011-08-10 Alan Guo

We study a game where two players take turns selecting points of a convex geometry until the convex closure of the jointly selected points contains all the points of a given winning set. The winner of the game is the last player able to…

Combinatorics · Mathematics 2021-04-20 Stephanie McCoy , Nándor Sieben

Subset Sum is a classical optimization problem taught to undergraduates as an example of an NP-hard problem, which is amenable to dynamic programming, yielding polynomial running time if the input numbers are relatively small. Formally,…

Data Structures and Algorithms · Computer Science 2018-07-24 Konstantinos Koiliaris , Chao Xu

Given $n$ piles of tokens and a positive integer $k \leq n$, the game Nim$^1_{n, =k}$ of exact slow $k$-Nim is played as follows. Two players move alternately. In each move, a player chooses exactly $k$ non-empty piles and removes one token…

Combinatorics · Mathematics 2021-02-09 Nikolay Chikin , Vladimir Gurvich , Konstantin Knop , Mike Paterson , Michael Vyalyi

This work is concerned with the study of the Game of Graph Nim -- a class of two-player combinatorial games -- on graphs with $4$ edges. To each edge of such a graph is assigned a positive-integer-valued edge-weight, and during each round…

Combinatorics · Mathematics 2025-09-08 Sayar Karmakar , Moumanti Podder , Souvik Roy , Soumyarup Sadhukhan

We study the periodicity of nim-sequences for subtraction games having subtraction sets with three elements. In particular, we give solutions in several cases, and we describe how these subtraction sets can be augmented by additional…

Combinatorics · Mathematics 2014-12-25 Nhan Bao Ho

We define a two-player combinatorial game in which players take alternate turns; each turn consists on deleting a vertex of a graph, together with all the edges containing such vertex. If any vertex became isolated by a player's move then…

Combinatorics · Mathematics 2016-08-03 Richard Adams , Janae Dixon , Jennifer Elder , Jamie Peabody , Oscar Vega , Karen Willis

Several works have shown unconditional hardness (via integrality gaps) of computing equilibria using strong hierarchies of convex relaxations. Such results however only apply to the problem of computing equilibria that optimize a certain…

Computational Complexity · Computer Science 2018-06-26 Pravesh K. Kothari , Ruta Mehta

Given two finite sets of integers $S\subseteq\NNN\setminus\{0\}$ and $D\subseteq\NNN\setminus\{0,1\}$,the impartial combinatorial game $\IMARK(S,D)$ is played on a heap of tokens. From a heap of $n$ tokens, each player can moveeither to a…

Discrete Mathematics · Computer Science 2015-11-10 Eric Sopena

We study a combinatorial game derived from a problem in the German National Mathematics Competition. In this game, two players take turns removing numbers from a finite set of natural numbers, aiming to satisfy a certain divisibility…

Combinatorics · Mathematics 2025-08-04 Tim Rammenstein

Turn-based discounted-sum games are two-player zero-sum games played on finite directed graphs. The vertices of the graph are partitioned between player 1 and player 2. Plays are infinite walks on the graph where the next vertex is decided…

Computer Science and Game Theory · Computer Science 2024-05-21 Ali Asadi , Krishnendu Chatterjee , Raimundo Saona , Jakub Svoboda

The convergence of online learning algorithms in games under self-play is a fundamental question in game theory and machine learning. Among various notions of convergence, last-iterate convergence is particularly desirable, as it reflects…

Computer Science and Game Theory · Computer Science 2025-11-11 Yang Cai , Haipeng Luo , Chen-Yu Wei , Weiqiang Zheng

In a recent arXiv-manuscript Fox studies infinite subtraction games with a finite (ternary) and aperiodic Sprague-Grundy function. Here we provide an elementary example of a game with the given properties, namely the game given by the…

Combinatorics · Mathematics 2015-03-26 Urban Larsson

We study zero-sum (combinatorial) games, within the framework of so-called Richman auctions (Lazarus et al. 1996) namely, we modify the alternating play scoring ruleset Cumulative Subtraction (CS) (Cohensius et al. 2019), to a discrete…

Computer Science and Game Theory · Computer Science 2020-03-13 Urban Larsson , Neel Patel , Ravi Kant Rai

In this paper, we study algorithms for special cases of energy games, a class of turn-based games on graphs that show up in the quantitative analysis of reactive systems. In an energy game, the vertices of a weighted directed graph belong…

Data Structures and Algorithms · Computer Science 2023-11-17 Sebastian Forster , Antonis Skarlatos , Tijn de Vos

Impartial subtraction games on the nonnegative integers have been studied by many and discussed in detail in for example the remarkable work Winning Ways by Conway, Berlekamp and Guy. We describe how comply variations of these games,…

Number Theory · Mathematics 2012-09-11 Urban Larsson

Partially-ordered set games, also called poset games, are a class of two-player combinatorial games. The playing field consists of a set of elements, some of which are greater than other elements. Two players take turns removing an element…

Computer Science and Game Theory · Computer Science 2011-11-22 Adam O. Kalinich

The subset sum algorithm is a natural heuristic for the classical Bin Packing problem: In each iteration, the algorithm finds among the unpacked items, a maximum size set of items that fits into a new bin. More than 35 years after its first…

Computer Science and Game Theory · Computer Science 2009-07-27 Leah Epstein , Elena Kleiman , Julian Mestre

We study a variant of 3-pile Nim in which a move consists of taking tokens from one pile and, instead of removing then, topping up on a smaller pile provided that the destination pile does not have more tokens then the source pile after the…

Combinatorics · Mathematics 2016-05-12 Nhan Bao Ho

We present a deterministic algorithm, solving discounted games with $n$ nodes in $n^{O(1)}\cdot (2 + \sqrt{2})^n$-time. For bipartite discounted games our algorithm runs in $n^{O(1)}\cdot 2^n$-time. Prior to our work no deterministic…

Data Structures and Algorithms · Computer Science 2020-10-27 Alexander Kozachinskiy