I guess the answer is yes, since I was able to solve it on this basis.

Funny kata to figure out.

Question about "a string representing a grid like in the above pictures".

Does this mean there will always be either 0 or 2 '-' between every pair of '+'?

they were?

Funny kata to learn some new concepts with.

You can skip door 8 and go directly to door 9. You end up paying 7 + 9 + 10 = 26.

I don't understand the underlying maths: e.g. if we start at 7, and the jewels are behind doors number 10, we haveto pay 7 + 8 + 9 + 10 = 34, however the description says it is 26. Where is 26 coming from?

yeah, he is experient!

Interesting kata, thanks.

Enjoyable programming kata indeed.

del

Maybe this paragraph will help? https://docs.codewars.com/training/troubleshooting#timeout

I get this answer:
Test Results:
Random Tests
cost -- random
Test Passed
Test Passed
Test Passed
Test Passed
Test Passed
Test Passed
Test Passed
Test Passed
Test Passed
Test Passed
make_min_tree -- random
Test Passed
Test Passed
STDERR
Execution Timed Out (12000 ms)

How can I understans what is going on?

Sorry for the typo, I have correct the comment. Thanks.

The left side of == is a tower of hight 3, whereas the right side is a tower of hight 4, it seems. That's what i find confusing. Do you mean:

-- tower(13, 3, 31) == 13 ^ (30 + tower(13, 2, 30)) % 31

This would match the Python test.