Lists generation problem

Readme.md

• There are two kinds of items: A and B
• Each item B could be replaced by A' and A"
• Given a list with items A and B (the order is not important), generate the most quantity of target-lists only with items A, A' and A" below the time limit t
• Each target-list is sorted after generation, so there isn't necessary to generate each permutation (only replacements are sufficient)
• The source list have an arbitrary size
• The number of unique possibilities is n² where n is the number of B items
• A items doesn't need to be modified, so it could be reused

Given the source list:

[A, A, B, A, B]

These are the relevant target-lists:

[A, A, A', A, A']
[A, A, A", A, A']
[A, A, A", A, A"]

Notice the absence of [A, A, A', A, A"]: as the target list is ordered, this option is not relevant.