Constant factor approximations to edit distance on far input pairs in nearly linear time

04/10/2019

∙

by   Michal Koucký, et al.

∙

0

∙

share

For any T ≥ 1, there are constants R=R(T) ≥ 1 and ζ=ζ(T)>0 and a randomized algorithm that takes as input an integer n and two strings x,y of length at most n, and runs in time O(n^1+1/T) and outputs an upper bound U on the edit distance ED(x,y) that with high probability, satisfies U ≤ R(ED(x,y)+n^1-ζ). In particular, on any input with ED(x,y) ≥ n^1-ζ the algorithm outputs a constant factor approximation with high probability. A similar result has been proven independently by Brakensiek and Rubinstein (2019).