The solution was prohibiting any comment, which is not a wise one :p

what language? I checked CSharp tests and they are ok.

each sub 3x3 matrix should be 123456789

1 2 3 | 4 5 6 | 7 8 9
2 3 1 | 5 6 4 | 8 9 7
3 1 2 | 6 4 5 | 9 7 8
------+-------+------
4 5 6 | 7 8 9 | 1 2 3
5 6 4 | 8 9 7 | 2 3 1
6 4 5 | 9 7 8 | 3 1 2
------+-------+------
7 8 9 | 1 2 3 | 4 5 6
8 9 7 | 2 3 1 | 5 6 4
9 7 8 | 3 1 2 | 6 4 5

fixed.

The 40 random tests + fixed tests on my solution take 3490ms to run, perhaps your code needs some optimization, please share your code for further help :)

the java tests were recently translated so i don't knoww how well tested they are, i will look at them when i can and get back to you on that :)