dukuso wrote:These results are unexpected to me ... did eleven expect it when he/she started ?

After my results in the high clue search i was optimistic. But i did not expect to find so much.

Is the same method maybe useful to find hard exact-cover problems or hard

SAT-problems in general ?

A google search showed, that the genetic algorithm heuristic has been used several times to solve exact cover problems and other SAT problems like TSP.

E.g. i had a look at the sketchy article A New Genetic Algorithm for Set Covering Problems, which shows some similarities to what i have done.

Not being an expert, i dont know, how they perform compared to other methods, but i guess that there is a niche of special problems, where they give competitive results.

Of course all depends on one's choices, how the selection (fitness/filter) and mutation/crossover (expand) is defined.