Approximate string matching: A simpler faster algorithm

We give two algorithms for finding all approximate matches of a pattern in a text, where the edit distance between the pattern and the matching text substring is at most k. The first algorithm, which is quite simple, runs in time O(nk³/m + n + m) on all patterns except k-break periodic strings (defined later). The second algorithm runs in time O(nk⁴/m + n + m) on k-break periodic patterns. The two classes of patterns are easily distinguished in O(m) time.