Shortest common supersequence

The shortest common supersequence is a problem closely related to the longest common subsequence.

Shortest common supersequence is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.

Given two strings u and v, the shortest common supersequence of u and v is the shortest possible sequence s such that both u and v are a subsequence of s.

As an example, you'll take the strings 'AACCTTGG' and 'ACACTGTGA' and you should get 'AACTGG' for instance (sometimes several solutions are possible, though they should all have the same length by definition). This example is taken from a rosalind task.