We prove that the 2n−1 lower bound on the competitive ratio of the PERMUTATION algorithm for online metric matching with n servers holds even if the number m of distinct servers is as low as 4, and even on the line, a simple space where lower competitive ratios are often possible. The same technique yields a [Formula presented.] lower bound on the competitive ratio of PERMUTATION in the special case of n/m servers at each of m evenly-spaced points on the line, improving for all m > 4 a recent m+1 lower bound and disproving its conjectured optimality.

PERMUTATION for online metric matching with m distinct servers

Peserico E.;Scquizzato M.
2026

Abstract

We prove that the 2n−1 lower bound on the competitive ratio of the PERMUTATION algorithm for online metric matching with n servers holds even if the number m of distinct servers is as low as 4, and even on the line, a simple space where lower competitive ratios are often possible. The same technique yields a [Formula presented.] lower bound on the competitive ratio of PERMUTATION in the special case of n/m servers at each of m evenly-spaced points on the line, improving for all m > 4 a recent m+1 lower bound and disproving its conjectured optimality.
2026
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11577/3612739
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