The purpose of this algorithm is to calculate, given sequences S and T, the maximum coverage of T using only subsequences and reverse subsequences of S, with a minimum length of l, eventually overlapped, and, in such maximum coverage, minimizing the number of subsequences used.
The problem is solved executing a preelaboration of S (unrelated from the sequence where the maximum coverage will be later searched, so usable for every possible T) generating a graph who enables to quickly recognize S subsequences.
First, we need to generate graph G from S and graph G' from S reversed, then, using G, G' and T, a fast calculation give the T maximum coverage.