In python bus_times and boy_times should be tuples.

The function should return a set of tuples.

Now works.

Random tests generate strings with 'x' instead of '+'

Wrong reference soluition, e.g.:

screws = 'x---x-'
Log
mode1=26 mode2=20
20 should equal 11

fractions should be allowed. Args and result should be of type Fraction.

• Duplicate
• No sample tests
• No random tests
• No description

I don't consider the simple version a duplicate (unless there is already a kata about rational lcm).

Python has integer lcm. Rational lcm requires a couple of lines of code in addition to imports.

5 people solved it without the random tests, and now the solutions are invalidated.

There is only one valid solution, and it contains this comment:

        # This is wrong, I use the new n instead of the old one
        # But that's the only way it works
        # Pretty sure it's a bug in the reference solution

Use proper type (Fraction) for input/output and remove restrictions.

IMHO without strings and restrictions this can be a good 7kyu kata.

There isn't much space for a yellow/purple rational lcm from scratch since there are already:

• reimplement a fraction class
• reimplement integer lcm/gcd
• parse/stringify all types of numbers

and it would be mostly a duplicate.

Reference solution in wrong (~ 20% wrong results). E.g.:

args: ('314/732', '136/204')
'314/3' should equal '157/3'

but 157/3 is not a multiple of 136/204 (=2/3).

• Restrictions should be mentioned in description.
• Forbidding str, tuple, itertools, ... doesn't make sense.
• No random tests.
• Sample tests are useless (no fractions).
• lcm of an empty set is 1.

If multiple transformation rules yield identical output states, do not remove duplicates.

If you don't remove duplicates then

'MUUUI' -> ['MUUUIU', 'MUUUIUUUI', 'MUI', 'MUI']

but tests expect

'MUUUI' ->  ['MUUUIU', 'MUUUIUUUI', 'MUI']

If you mean "keep duplicates from different rules, but drop duplicates from multiple application of the same rule", it should be stated clearly in description and tested. All current valid solutions drop all duplicates.

.

No random tests.