Landau and Schmidt [4] studied the problem of finding the two consecutive copies in a sequence of length n such that the edit distance (a match costs 0 and a mismatch/indel costs 1) between the two copies is at most k. The running time of the algorithm is O(kn log k log(n/kL)). Schmidt [5] used weighted grid digraphs for finding all non-overlapping pairs of substrings (not necessarily consecutive) with the highest scores in a given string of length n. The algorithm can handle any score scheme. It requires O(n2 log n) time and Θ(n2) space. In both [4] and [5], only two copies of the pattern are considered.