eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Leibniz International Proceedings in Informatics
1868-8969
2011-03-11
69
80
10.4230/LIPIcs.STACS.2011.69
article
Tight Bounds For Distributed MST Verification
Kor, Liah
Korman, Amos
Peleg, David
This paper establishes tight bounds for the Minimum-weight Spanning Tree (MST) verification problem in the distributed setting. Specifically, we provide an MST verification algorithm that achieves simultaneously tilde ~O(|E|) messages and $tilde O(sqrt{n} + D) time, where |E| is the number of edges in the given graph G and D is G's diameter. On the negative side, we show that any MST verification algorithm must send Omega(|E|) messages and incur ~Omega(sqrt{n} + D) time in worst case.
Our upper bound result appears to indicate that the verification of an MST may be easier than its construction, since for MST construction, both lower bounds of Omega(|E|) messages and
Omega(sqrt{n} + D) time hold, but at the moment there is no known distributed algorithm that constructs an MST and achieves simultaneously tilde O(|E|) messages and ´~O(sqrt{n} + D) time. Specifically, the best known time-optimal algorithm (using ~O(sqrt{n} + D) time) requires O(|E|+n^{3/2}) messages, and the best known message-optimal algorithm (using ~O(|E|) messages) requires O(n) time.
On the other hand, our lower bound results indicate that the verification of an MST is not significantly easier than its construction.
https://drops.dagstuhl.de/storage/00lipics/lipics-vol009-stacs2011/LIPIcs.STACS.2011.69/LIPIcs.STACS.2011.69.pdf
distributed algorithms
distributed verification
labeling schemes
minimum-weight spanning tree