The study of approximately periodic strings is relevant to diverse applications such as molecular biology, data compression, and computer-assisted music analysis. Here we study di erent forms of approximate periodicity under a variety of distance functions. We consider three related problems, for two of which we derive polynomial-time algorithms; we then show that the third problem is NP-complete. c 2001 Elsevier Science B.V. All rights reserved.
Jeong Seop Sim, Costas S. Iliopoulos, Kunsoo Park,