Amazing kata, realized immediately that it is a generalization of a famous "high school pyramid" :P
getting it right took some time though

first solution O(N^4), TLE;
second solution O(N^2), TLE;
third solution O(N), pass!
amazing kata!

it passes the test without caching or precalculating

the solution I provided is overkill for this problem, it finds all connected components in O(rows*cols*α(rows*cols)) time (t.l.d.r.: proportional to the matrix size, which is optimal).

runs in linear time.

Thanks for checking the issue, wish you a happy 2024!

In golang there are some issues with the testing framework,
at some point during the random tests it outputs:

With arr = [-45 -34 -30 -6 -5 -48 43 8], command = "< <"
Expected
    <[][]int | len:2, cap:2>: [
        [-45, -34, -30, -6, -5, 43],
        [-45, -34, -30, -6, -5, 8],
    ]
to equal
    <[][]int | len:2, cap:2>: [
        [-45, -34, -30, -6, -5, 8],     #####NOTICE
        [-45, -34, -30, -6, -5, 8],     ##### it has been repeated... which is wrong by spec.
    ]

I checked using printfs that my code outputs the correct result, I.E.:

[[-45, -34, -30, -6, -5, 43], [-45, -34, -30, -6, -5, 8]]

moreover the testing code sometimes fails to find all solutions...

With arr = [-2 -41 -4 -21 -31 -52 26 -41], command = ">>"
Expected
    <[][]int | len:2, cap:2>: [
        [-2, -4, -21, -31, -52],
        [-2, -4, -21, -31, -41],
    ]
to equal
    <[][]int | len:1, cap:1>: [
        [-2, -4, -21, -31, -52],  #### here it is missing the other possibility
    ]