论文标题

半盖范围搜索和刺伤问题的下限

Lower Bounds for Semialgebraic Range Searching and Stabbing Problems

论文作者

Afshani, Peyman, Cheng, Pingan

论文摘要

在Semialgebraic范围搜索问题中,我们将以$ \ Mathbb {r}^d $ S.T.中的预处理$ n $s.t。对于从恒定复杂性的半分类集的家族的任何查询范围,所有与范围相交的点都可以有效地报告或计数。当范围由简单组成时,可以使用$ s(n)$空间解决问题,并使用$ q(n)$查询时间,$ s(n)q^d(n)= \ tilde {o} {o}(n^d)$,此权衡几乎很紧。因此,存在使用$ o(n^{1-1/d})$ o(n^{1-1/d})$查询时间和使用$ o(n^d)$ space的快速查询结构的$ o(n^{1-1/d})使用$ o(n^{1-1/d})的低空间结构。但是,对于一般的半格式范围,只有低空间解决方案,但最佳解决方案与单纯曲线相同的权衡曲线匹配。有人认为,对于快速查询案例,可以做同样的事情,但是这个开放的问题仍未解决。 在这里,我们反驳了这个猜想。我们给出了第一个非平凡的下限,用于诊断和相关问题。我们表明,任何用于报告两个同心圆之间的数据结构,$ q(n)$查询时间必须使用$ s(n)=ω(n^{3-o(1)}/q(n)^5)$ space,含义为$ q(n)= o(\ log log^{o(\ log^{o(1)n)$,$,$,$,$,n^n^$(1)$(1)。我们还研究了报告表格$ y = \ sum_ = \ sum_ = 0}^δA_ix^i $的两个多项式之间的点的问题,其中$ a_0,\ cdots,a_Δ$在查询时间给出。我们显示$ s(n)=ω(n^{δ+1-o(1)}/q(n)^{δ^^2+δ})$。因此,对于$ q(n)= o(\ log^{o(1)} n)$,我们必须使用$ω(n^{δ+1-o(1)})$ space。对于双重半刺伤问题,我们表明,在线性空间中,任何解决2D环刺的数据结构都必须使用$ω(n^{2/3})$查询时间。这几乎与线性化上限匹配。对于一般的半格式平板刺伤问题,我们再次显示出几乎紧密的下限。

In the semialgebraic range searching problem, we are to preprocess $n$ points in $\mathbb{R}^d$ s.t. for any query range from a family of constant complexity semialgebraic sets, all the points intersecting the range can be reported or counted efficiently. When the ranges are composed of simplices, the problem can be solved using $S(n)$ space and with $Q(n)$ query time with $S(n)Q^d(n) = \tilde{O}(n^d)$ and this trade-off is almost tight. Consequently, there exists low space structures that use $\tilde{O}(n)$ space with $O(n^{1-1/d})$ query time and fast query structures that use $O(n^d)$ space with $O(\log^{d} n)$ query time. However, for the general semialgebraic ranges, only low space solutions are known, but the best solutions match the same trade-off curve as the simplex queries. It has been conjectured that the same could be done for the fast query case but this open problem has stayed unresolved. Here, we disprove this conjecture. We give the first nontrivial lower bounds for semilagebraic range searching and related problems. We show that any data structure for reporting the points between two concentric circles with $Q(n)$ query time must use $S(n)=Ω(n^{3-o(1)}/Q(n)^5)$ space, meaning, for $Q(n)=O(\log^{O(1)}n)$, $Ω(n^{3-o(1)})$ space must be used. We also study the problem of reporting the points between two polynomials of form $Y=\sum_{i=0}^Δa_i X^i$ where $a_0, \cdots, a_Δ$ are given at the query time. We show $S(n)=Ω(n^{Δ+1-o(1)}/Q(n)^{Δ^2+Δ})$. So for $Q(n)=O(\log^{O(1)}n)$, we must use $Ω(n^{Δ+1-o(1)})$ space. For the dual semialgebraic stabbing problems, we show that in linear space, any data structure that solves 2D ring stabbing must use $Ω(n^{2/3})$ query time. This almost matches the linearization upper bound. For general semialgebraic slab stabbing problems, again, we show an almost tight lower bounds.

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