thing is you return float although the result always is an integer value

Funny kata all i had to do was press backspace three times.

It doesn't. Either it got lucky with the random tests or the tests have been changed since this solution.

I ran the code and it FAILED this test:

 Testing for [1, 1, 0, 1, 1]
It should work for random inputs too: 'Yes' should equal 'No'

when the key=[1,1,1] the test flase

should join a determine

if the list length is not n*n should "No"

How this code handles non perfect square keys? I got one in my attempt