Thanks

Recall the Edit Distance (Sequence Alignment) problem: given two strings over the same alphabet and mismatch and gap penalties, find an alignment of minimal cost. One of the most common uses of the minimum edit distance algorithm is in computational biology. DNA sequences are composed of four amino-acids, denoted by the letters A, C, T, G. Mutation over the course of evolution changes the sequences by deleting, inserting, or substituting amino-acids. The smaller the edit distance between some two sequences, the smaller the evolutionary distance between them. Thus, biological sequences are often aligned to minimize the edit distance between them