Locating maximal approximate runs in a string

International audienceAn exact run in a string T is a non-empty substring of T that is a repetition of a smaller substring. Finding maximal exact runs in strings is an important problem and therefore a well-studied one in the area of stringology. For a given string T of length n, finding all maximal exact runs in the string can be done in O(n log n) time on general ordered alphabets or O(n) time on integer alphabets. In this paper, we investigate the maximal approximate runs problem: for a given string T and a number k, find non-empty substrings T of T such that changing at most k letters in T transforms them into a maximal exact run. We present an O(nk 2 log 2 k + occ) algorithm to solve this problem, where occ is the number of substrings found