Just thought I'd have a go at it myself, using regex instead of the (obviously better) XOR approach.

My rough check, with 1 mismatch, works out to the same order of magnitude as choroba's first try, but maybe 2x slower. With more mismatches, my solution goes exponential creating regexes, but should take a bit less time in the matching phase. (Hand-wavy arguments go here.)

Code:

<Reveal this spoiler or all in this thread>

-QM
--
Quantum Mechanics: The dreams stuff is made of

In reply to Re: How do you match a stretch of at least N characters by QM
in thread How do you match a stretch of at least N characters by Anonymous Monk

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