Truly Subcubic Min-Plus Product for Less Structured Matrices, with Applications
Truly Subcubic Min-Plus Product for Less Structured Matrices, with Applications
复制标题
适用于较少结构化矩阵的真正次三次最小加乘积及其应用
DOI:
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发表时间:
2019
期刊:
影响因子:
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通讯作者:
Yinzhan Xu
中科院分区:
文献类型:
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作者:
V. V. Williams;Yinzhan Xu
The goal of this paper is to get truly subcubic algorithms for Min-Plus product for less structured inputs than what was previously known, and to apply them to versions of All-Pairs Shortest Paths (APSP) and other problems. The results are as follows:
(1) Our main result is the first truly subcubic algorithm for the Min-Plus product of two $n\times n$ matrices $A$ and $B$ with $\text{polylog}(n)$ bit integer entries, where $B$ has a partitioning into $n^{\epsilon}\times n^{\epsilon}$ blocks (for any $\epsilon>0$) where each block is at most $n^\delta$-far (for $\delta<3-\omega$, where $2\leq \omega<2.373$) in $\ell_\infty$ norm from a constant rank integer matrix. This result presents the most general case to date of Min-Plus product that is solvable in truly subcubic time.
(2) The first application of our main result is a truly subcubic algorithm for APSP in a new type of geometric graph. Our result extends the result of Chan'10 in the case of integer edge weights by allowing the weights to differ from a function of the end-point identities by at most $n^\delta$ for small $\delta$.
(3) In the second application we consider a batch version of the range mode problem in which one is given a length $n$ sequence and $n$ contiguous subsequences, and one is asked to compute the range mode of each subsequence. We give the first $O(n^{1.5-\epsilon})$ time for $\epsilon>0$ algorithm for this batch range mode problem.
(4) Our final application is to the Maximum Subarray problem: given an $n\times n$ integer matrix, find the contiguous subarray of maximum entry sum. We show that Maximum Subarray can be solved in truly subcubic, $O(n^{3-\epsilon})$ (for $\epsilon>0$) time, as long as the entries are no larger than $O(n^{0.62})$ in absolute value.
We also improve all the known conditional hardness results for the $d$-dimensional variant of Maximum Subarray.
DOI:
10.1137/1.9781611975031.91
发表时间:
2018
期刊:
Twenty-Ninth Annual ACM-SIAM Symposium on Discrete Algorithms
影响因子:
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作者:
Lincoln, A.;Vassilevska Williams, V.;Williams, R.
通讯作者:
Williams, R.