I only used printf locally to debug the function. Ok that is strange. The links in my first message, are from failed tests in codewars and are clearly missing the #. If I test the last link you posted, locally, it returns "www.Inquisition.com/Spanish/?page=42#nobody-expects-it" just fine.

Edit: A few other addresses that did not pass the test.

submitted: https://sausage.mil
expected: https://sausage.mil
submitted: spam.orgwww.tomato.mil
expected: spam.org
Test Passed
Test Passed
submitted: www.spam.govbeans.net
expected: www.spam.gov
Test Passed
Test Passed
submitted: http://tea.orgor.edu
expected: http://tea.org
Test Passed
submitted: http://www.tea.milnt
expected: http://www.tea.mil
Test Passed
Test Passed
submitted: https://sausage.orgrg
expected: https://sausage.org
submitted: www.tomato.orge.org
expected: www.tomato.org
submitted: www.toast.intg
expected: www.toast.int

c-kata seems to have some issues with the testcases.

one example how some a fails:

submitted: www.Inquistition.com/Spanish/?page=42errent.com
expected: www.Inquistition.com/Spanish/?page=42

to me it seems, that there is a missing # in the link provided, which than obviously can't be dedected by my solution. locally run tests work perfectly and even some of the codewars-tests pass without any issues.

you are right. my mistake :)

Has anybody an idea why I get a "Test Error: Oups" or what this could mean?
I tested my function with [0, 7, 10, 2, 4, 3, 5,102] and get [10, 2, 4, 102] in return.

wow, thats an awesome solution!