The one-round Voronoi game replayed

We consider the one-round Voronoi game, where player one (``White'', called ``Wilma'') places a set of n points in a rectangular area of aspect ratio r <=1, followed by the second player (``Black'', called ``Barney''), who places the same number of points. Each player wins the fraction of the board closest to one of his points, and the goal is to win more than half of the total area. This problem has been studied by Cheong et al., who showed that for large enough $n$ and r=1, Barney has a strategy that guarantees a fraction of 1/2+a, for some small fixed a. We resolve a number of open problems raised by that paper. In particular, we give a precise characterization of the outcome of the game for optimal play: We show that Barney has a winning strategy for n>2 and r>sqrt{2}/n, and for n=2 and r>sqrt{3}/2. Wilma wins in all remaining cases, i.e., for n>=3 and r<=sqrt{2}/n, for n=2 and r<=sqrt{3}/2, and for n=1. We also discuss complexity aspects of the game on more general boards, by proving that for a polygon with holes, it is NP-hard to maximize the area Barney can win against a given set of points by Wilma.Comment: 14 pages, 6 figures, Latex; revised for journal version, to appear in Computational Geometry: Theory and Applications. Extended abstract version appeared in Workshop on Algorithms and Data Structures, Springer Lecture Notes in Computer Science, vol.2748, 2003, pp. 150-16

Competitive location problems : balanced facility location and the one-round Manhattan Voronoi game

We study competitive location problems in a continuous setting, in which facilities have to be placed in a rectangular domain R of normalized dimensions of 1 and ρ≥1, and distances are measured according to the Manhattan metric. We show that the family of 'balanced' facility configurations (in which the Voronoi cells of individual facilities are equalized with respect to a number of geometric properties) is considerably richer in this metric than for Euclidean distances. Our main result considers the 'One-Round Voronoi Game' with Manhattan distances, in which first player White and then player Black each place n points in R; each player scores the area for which one of its facilities is closer than the facilities of the opponent. We give a tight characterization: White has a winning strategy if and only if ρ≥n; for all other cases, we present a winning strategy for Black

Competitive location problems : balanced facility location and the One-Round Manhattan Voronoi Game

We study competitive location problems in a continuous setting, in which facilities have to be placed in a rectangular domain R of normalized dimensions of 1 and ρ≥ 1 , and distances are measured according to the Manhattan metric. We show that the family of balanced facility configurations (in which the Voronoi cells of individual facilities are equalized with respect to a number of geometric properties) is considerably richer in this metric than for Euclidean distances. Our main result considers the One-Round Voronoi Game with Manhattan distances, in which first player White and then player Black each place n points in R; each player scores the area for which one of its facilities is closer than the facilities of the opponent. We give a tight characterization: White has a winning strategy if and only if ρ≥ n; for all other cases, we present a winning strategy for Black

The Stackelberg game : responses to regular strategies

Following the solution to the One-Round Voronoi Game in arXiv:2011.13275, we naturally may want to consider similar games based upon the competitive locating of points and subsequent dividing of territories. In order to appease the tears of White (the first player) after they have potentially been tricked into going first in a game of point-placement, an alternative game (or rather, an extension of the Voronoi game) is the Stackelberg game where all is not lost if Black (the second player) gains over half of the contested area. It turns out that plenty of results can be transferred from One-Round Voronoi Game and what remains to be explored for the Stackelberg game is how best White can mitigate the damage of Black's placements. Since significant weaknesses in certain arrangements were outlined in arXiv:2011.13275, we shall first consider arrangements that still satisfy these results (namely, White plays a certain grid arrangement) and then explore how Black can best exploit these positions

Search algorithm to find optimum strategies to shape political action with subjective assessment

This paper introduces a problem related to decision making and the shaping of political strategies in the course of one term of office, in which the government and the opposition shape their proposals for action on two issues that are relevant for the citizens. A variable component is considered regarding both the relevance of the issues to be dealt with and the strategies that the parties are presumed to adopt. The aim of this study is to find the optimum strategies for the two majority parties of a country, while allowing them to vary their proposals to a certain degree. In addition, the process is dynamic because the proposals are intended to be modified taking into account the other party’s foreseen action. The contribution of this article lies in this approach, as well as in its taking into account variable components. The problem is dealt with from a geometric point of view, and a search algorithm to find optimum strategies is developed