OP solved it, closing

Your solution fails one of the sample tests, and you can see sample tests. It crashes on this one:

    Assert::That(determinant(vector< vector<long long> > {
      vector<long long> {1}
    }), Equals(1));

It's difficult to tell exactly without seeing your code, but it looks like an out-of-bounds read - most probably reading elements out of bounds of a vector, or something like this.

See @hobosky's comment.

it may happen that the input string have leading, trailing whitespaces and more than a unique whitespace between two consecutive numbers

Maybe it was related to that?

Your solution seems to pass, so I believe you found your mistake?

And that's what the error message is telling you it's wrong.

Expected: equal to 49085499 Actual: 50973523 // <- this is what your code returned
//                    ^ this is the expected value

Get rid of those global variables.

There are no error in the kata. Sorry but it's up to you to correct your code. Follow @hobovsky's advice.

Does your code work when you run two tests in a row, in one run of your testing program?

You should say your language and what was the input...
Anyway not a kata issue, there are no errors in the tests.