Brief Announcement: A Randomness-efficient Massively Parallel Algorithm for Connectivity
Brief Announcement: A Randomness-efficient Massively Parallel Algorithm for Connectivity
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简短公告:一种随机高效的大规模并行连接算法
DOI:
10.1145/3465084.3467951
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发表时间:
2021
期刊:
影响因子:
--
通讯作者:
Tan, Li-Yang
中科院分区:
文献类型:
--
作者:
Charikar, Moses;Ma, Weiyun;Tan, Li-Yang
We give a randomness-efficient Massively Parallel Computation (MPC) algorithm for deciding whether an undirected graph is connected. For Connectivity on n-vertex, m-edge graphs whose components have diameter at most D = 2o(log n/ log log n), our algorithm runs in R = O(log D + log logm/n,.n) rounds and uses a total of (log n)O(R) random bits, O(m) machines, and n1-Ω(1) space per machine with good probability.1 With good probability means with probability at least 1 - 1/poly ((m log n)/n), which is the same as in Liu, Tarjan, and Zhong (SPAA '20). Our algorithm achieves a super-polynomial saving in randomness complexity as compared to the breakthrough algorithm of Andoni et al. (FOCS '18) and the subsequent improvement by Behnezhad et al. (FOCS '19). Our algorithm has the same round complexity as that of Behnezhad et al., but uses more total space.Our Connectivity algorithm is an instantiation of a general method we develop for converting randomized algorithms in the PRAM model to highly randomness-efficient MPC algorithms. We show that for k = o(log n/log log n) and p = nO(1), any time-k p-processor randomized PRAM algorithm computing a function on n input bits can be converted to an equivalent strongly sublinear MPC algorithm with O(k) rounds and only a total of (log n)O(k) random bits. Our Connectivity algorithm follows from applying this method to the recent CRCW PRAM algorithm of Liu, Tarjan, and Zhong (SPAA '20).Our approach is based on the design of a pseudorandom generator for PRAM algorithms. The analysis of our generator is built on classic and influential results in circuit complexity (Hå stad '86; Nisan and Wigderson '88), which we generalize from the setting of small-depth circuits to the more powerful setting of PRAM algorithms. The parameters that we achieve are optimal given the current state of the art in complexity theory, in the sense that further improvements will imply ≠ NC1.
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DOI:
10.1145/3350755.3400249
发表时间:
2020
期刊:
32nd ACM Symposium on Parallelism in Algorithms and Architectures
影响因子:
--
作者:
Liu, Sixue Cliff;Tarjan, Robert E.;Zhong, Peilin
通讯作者:
Zhong, Peilin
DOI:
--
发表时间:
1984
期刊:
Symposium on the Theory of Computing
影响因子:
--
作者:
M. Klawe;W. Paul;N. Pippenger;M. Yannakakis
通讯作者:
M. Yannakakis
DOI:
--
发表时间:
2013
期刊:
2013 IEEE Conference on Computational Complexity
影响因子:
--
作者:
L. Trevisan;Tongke Xue
通讯作者:
Tongke Xue
DOI:
--
发表时间:
2019
期刊:
ACM SIGACT-SIGOPS Symposium on Principles of Distributed Computing
影响因子:
--
作者:
P. Bamberger;F. Kuhn;Yannic Maus
通讯作者:
Yannic Maus
DOI:
--
发表时间:
2016
期刊:
ACM-SIAM Symposium on Discrete Algorithms
影响因子:
--
作者:
David G. Harris
通讯作者:
David G. Harris