Streaming Periodicity with Mismatches
نویسندگان
چکیده
We study the problem of finding all k-periods of a length-n string S, presented as a data stream. S is said to have k-period p if its prefix of length n− p differs from its suffix of length n− p in at most k locations. We give a one-pass streaming algorithm that computes the k-periods of a string S using poly(k, logn) bits of space, for k-periods of length at most n 2 . We also present a two-pass streaming algorithm that computes k-periods of S using poly(k, logn) bits of space, regardless of period length. We complement these results with comparable lower bounds.
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