Not a syntax error, just lazy test making.

The test suite does not guard against equal_to_24 returning "It's not possible!" before calling eval (when an equation is expected). Thus, the tests try to run eval("It's not possible!"), and since "It's not possible!" is not valid Python syntax, a SyntaxError is raised.

Think there is a syntax error in the test cases.

This was after straight returning "It's not possible!"

Traceback (most recent call last):
  File "/workspace/default/tests.py", line 5, in <module>
    test.assert_equals(eval(equal_to_24(1,2,3,4)) , 24)
                       ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<string>", line 1
    It's not possible!
      ^
SyntaxError: unterminated string literal (detected at line 1)

Suggestion implemented & made description language agnostic.

Note the list isn't really sequential (the actual sequence for n-digit = 3 in ascending order goes like 100, 110, 111, 112, 113, 114, 115, 116, ...)

I think the description should include the number "100" in the number_of_duplicate_digits(3) example.

Thanks, removed.

You have a ghost JS version.

The description seems to indicate that two passes are required, but my solution passed by checking for a zero after only one pass. That's a little confusing and should be clarified.

Strictly a mathematical challenge more or less, nice kata for the record.

well said, updated, thanks

python new version to be updated.

They are not, BigInt is a wrapper around java.math.BigInteger iirc.

Expected 368559, but got 368559

EDIT: apparently, java.math.BigInteger and BigInt are not the same.

JavaScript translation

Oh, retired.
Anyway, then...