Looking at your solution it looks like you just like to add documentation for the sake of documentation, even when it results in illegible code and a ton of duplication/stating what is obvious even to novices. I won't claim the top solution to be best practices, but less is more in this case when the solution can be whittled down to a single standard lib function call.

I brute forced my way with programming constructs through this one but seeing the answers that took the far superior mathematical approach really opened up my eyes. Excellent kata to showcase a time where math really does matter (specifically knowledge of math formulas).

The golang version only covers array types of []string{} and make([]string, 5, 5) but not for [5]string. If you try to use [5]string the test fails.

Instructions were not clear about the random sets of data containing towns not found in the strng parameter, as well as expecting -1 to be returned rather than 0 when it happens. Was great debugging practice though.