论文标题

罗密欧与朱丽叶在森林等地区的会议

Romeo and Juliet Meeting in Forest Like Regions

论文作者

Misra, Neeldhara, Mulpuri, Manas, Tale, Prafullkumar, Viramgami, Gaurav

论文摘要

与对手的聚会游戏是由两个玩家演奏的图表上的游戏:促进者和分隔线。主持人有两个代理商,Divider的团队由$ K \ ge 1 $ $。虽然促进者的代理人的初始位置是固定的,但分隔线可以选择其代理的初始位置。然后,他们轮流将代理商转移到邻近的顶点(或留下),以促进者的目标将她的两个代理商带到同一顶点和Divider的目标以防止它。感兴趣的计算问题是确定促进者是否对$ k $代理商有针对Divider的获胜策略。 Fomin,Golovach和Thilikos [WG,2021]介绍了这款游戏,并证明它是Pspace-Hard和Co-W [2] - 由代理数量进行的参数。 这种硬度自然会激发问题的结构参数化。作者证明,当通过模块化宽度和允许回合的数量进行参数时,它承认了FPT算法。但是,他们从其他结构参数的角度留下了问题的复杂性。特别是,他们明确询问该问题是否允许相对于输入图的树宽。我们以否定的方式回答这个问题,并表明Rendezvous即使对于恒定树宽的图表也是Co-NP。此外,我们表明,当反馈顶点集数和代理数量参数化时,问题是co-w [1] - hard,当通过顶点封面数和代理的数量参数时,不太可能接受多项式内核。与这些硬度结果相辅相成,我们表明当通过顶点盖号和解决方案大小参数化时,集合是FPT。最后,对于最多两个和束束的树宽图,我们表明问题可以在多项式时间内解决。

The game of rendezvous with adversaries is a game on a graph played by two players: Facilitator and Divider. Facilitator has two agents and Divider has a team of $k \ge 1$ agents. While the initial positions of Facilitator's agents are fixed, Divider gets to select the initial positions of his agents. Then, they take turns to move their agents to adjacent vertices (or stay put) with Facilitator's goal to bring both her agents at same vertex and Divider's goal to prevent it. The computational question of interest is to determine if Facilitator has a winning strategy against Divider with $k$ agents. Fomin, Golovach, and Thilikos [WG, 2021] introduced this game and proved that it is PSPACE-hard and co-W[2]-hard parameterized by the number of agents. This hardness naturally motivates the structural parameterization of the problem. The authors proved that it admits an FPT algorithm when parameterized by the modular width and the number of allowed rounds. However, they left open the complexity of the problem from the perspective of other structural parameters. In particular, they explicitly asked whether the problem admits an FPT or XP-algorithm with respect to the treewidth of the input graph. We answer this question in the negative and show that Rendezvous is co-NP-hard even for graphs of constant treewidth. Further, we show that the problem is co-W[1]-hard when parameterized by the feedback vertex set number and the number of agents, and is unlikely to admit a polynomial kernel when parameterized by the vertex cover number and the number of agents. Complementing these hardness results, we show that the Rendezvous is FPT when parameterized by both the vertex cover number and the solution size. Finally, for graphs of treewidth at most two and girds, we show that the problem can be solved in polynomial time.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源