论文标题
彩色搜索中的分层类别
Hierarchical Categories in Colored Searching
论文作者
论文摘要
在彩色范围计数(CRC)中,输入是一组点,每个点都被分配为``color''(或``类别''),目标是将它们存储在数据结构中,以便有效地计数给定查询范围内的不同类别的数量。 CRC具有强大的动机,因为它允许数据结构处理分类数据。但是,CRC问题中的颜色(即类别)没有任何内部结构,而对于存在层次类别或单个输入属于多个类别的许多数据集而言,这种情况并非如此。由这些动机,我们考虑了可以代表此类结构的问题的变体。我们定义了该问题的两个变体,称为层次范围计数(HCC)和子类别有色范围计数(SCRC),并考虑可以是DAG或树的层次结构。我们表明,一些特殊树上的两个问题实际上等同于文献中其他众所周知的问题。基于这些,当可以将基础层次结构表示为树时,我们还提供了有效的数据结构。当现有的层次结构可以通过正交矢量问题减少时,我们显示了一般情况下的条件下限。
In colored range counting (CRC), the input is a set of points where each point is assigned a ``color'' (or a ``category'') and the goal is to store them in a data structure such that the number of distinct categories inside a given query range can be counted efficiently. CRC has strong motivations as it allows data structure to deal with categorical data. However, colors (i.e., the categories) in the CRC problem do not have any internal structure, whereas this is not the case for many datasets in practice where hierarchical categories exists or where a single input belongs to multiple categories. Motivated by these, we consider variants of the problem where such structures can be represented. We define two variants of the problem called hierarchical range counting (HCC) and sub-category colored range counting (SCRC) and consider hierarchical structures that can either be a DAG or a tree. We show that the two problems on some special trees are in fact equivalent to other well-known problems in the literature. Based on these, we also give efficient data structures when the underlying hierarchy can be represented as a tree. We show a conditional lower bound for the general case when the existing hierarchy can be any DAG, through reductions from the orthogonal vectors problem.