Abstract
The best known expected time for the all pairs shortest path problem on a directed graph with non-negative edge costs is O(n 2logn) by Moffat and Takaoka. Let the solution set be the set of vertices to which the given algorithm has so far established shortest paths. The Moffat-Takaoka algorithm maintains complexities before and after the critical point in balance, which is the moment when the size of the solution set is n−n/logn. In this paper, we remove the concept of critical point, whereby we make the algorithm simpler and seamless, resulting in a simpler analysis.
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Notes
We notice that the condition for while in line 19 can be simplified to T[w]≤n−n/logn, and line 18 can be removed. The above version clarifies the meaning of CP better.
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Takaoka, T. A simplified algorithm for the all pairs shortest path problem with O(n 2logn) expected time. J Comb Optim 25, 326–337 (2013). https://doi.org/10.1007/s10878-012-9550-3
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DOI: https://doi.org/10.1007/s10878-012-9550-3