论文标题
搜索与搜索崩溃的选举控制类型
Search versus Search for Collapsing Electoral Control Types
论文作者
论文摘要
选举控制类型是试图通过改变其组成和结构方面来改变选举结果的方式[BTT92]。我们说,如果每个可能的输入(通常由候选人集,投票集,一个焦点候选者,有时与未尝试更改的性质相关的其他参数组成),则两种兼容(即具有相同的输入类型)控制类型,这些控制类型与同一选举系统e形成崩溃对。对于Hemaspaandra,Hemaspaandra和Menton [HHM20]发现的七个将军(即为所有选举系统持有)的每一个(即所有选举系统),以及Carleton等人的其他各个选举控制类型。 [CCH+ 22]对于否决和批准(以及根据该论文定理3.6和3.9的许多其他选举系统),崩溃对的两个成员都具有相同的复杂性,因为它们与集合相同。但是,具有相同的复杂性(作为集合)不足以确保作为搜索问题,它们具有相同的复杂性。在本文中,我们探讨了崩溃对的搜索版本之间的关系。对于Hemaspaandra,Hemaspaandra和Menton [HHM20]和Carleton等人的每对崩溃。 [CCH+ 22],我们证明了这对成员的搜索复杂性是多项式相关的(对于获胜者问题本身不在多项式时间时,访问给出了赢家问题的oracle)。除此之外,我们还提供了有效的降低,从解决方案到一个解决方案将解决方案计算到另一个解决方案。对于混凝土系统的多个否决权和批准,我们完全确定它们(由于结果)多项式相关的崩溃 - 搜索问题对是多项式时间的可计算,哪些是NP-HARD。
Electoral control types are ways of trying to change the outcome of elections by altering aspects of their composition and structure [BTT92]. We say two compatible (i.e., having the same input types) control types that are about the same election system E form a collapsing pair if for every possible input (which typically consists of a candidate set, a vote set, a focus candidate, and sometimes other parameters related to the nature of the attempted alteration), either both or neither of the attempted attacks can be successfully carried out. For each of the seven general (i.e., holding for all election systems) electoral control type collapsing pairs found by Hemaspaandra, Hemaspaandra, and Menton [HHM20] and for each of the additional electoral control type collapsing pairs of Carleton et al. [CCH+ 22] for veto and approval (and many other election systems in light of that paper's Theorems 3.6 and 3.9), both members of the collapsing pair have the same complexity since as sets they are the same set. However, having the same complexity (as sets) is not enough to guarantee that as search problems they have the same complexity. In this paper, we explore the relationships between the search versions of collapsing pairs. For each of the collapsing pairs of Hemaspaandra, Hemaspaandra, and Menton [HHM20] and Carleton et al. [CCH+ 22], we prove that the pair's members' search-version complexities are polynomially related (given access, for cases when the winner problem itself is not in polynomial time, to an oracle for the winner problem). Beyond that, we give efficient reductions that from a solution to one compute a solution to the other. For the concrete systems plurality, veto, and approval, we completely determine which of their (due to our results) polynomially-related collapsing search-problem pairs are polynomial-time computable and which are NP-hard.