Yes, in description we should have a point about that we will have invalid zipcodes for input

Mostly trial and error using the web-gui.
One way to make make the thinking slightly easier is a few properties of the problem.

1. You only need to find how to turn on the middle light, a diagonal corner light and a middle corner light. Then you can rotate the solutions to get all of the combinations.
2. If you keep track of button presses to get to a specific light combination, you can add two such combinations and do a modulus(2), on all numbers to get a new minimum number of presses to get to the combinations of light switches.

It is a little hard to describe in text though. I recomend pen and paper.

Good!

I see now, thank you very much for your explanation, fellow comrade!

The tests are not broken. I tried many solutions and they worked fine.
Please read this and correct your code and it should pass:
https://www.geeksforgeeks.org/using-namespace-std-considered-bad-practice/.

Not a kata error: I tried many solutions and they worked fine.
Please see below my answer to your previous post.

this kata has an error in the test cases : main.cpp:195:45: error: reference to 'data' is ambiguous;

Nice kata, fun to solve.

Dude, I think that the tests are broken, idk why but when i submit it is showing me this kind of error: reference to 'data' is ambiguous
assertFuzzyEquals(Rainfall::mean("London", data), if I am wrong please help me understand where is the issue.

From my point of view this kata has a problem with the random test. Idk why but in the end of the input string there is a comma(','), and I am not sure that it should be there. At least you shoud write in the description that there is some king of test idk. But for me it was kinda sketchy to realize that this is the problem of why my code was failing.

hello there! Can you explain to me how did you come out with that pattern? How did you figured out which light to turn off and in what order ?

hello there! Can you explain to me how did you come out with that pattern ? (i mean the one stored in the array solver).

thank you mister !

when some c++ wizard like you ports it to c++. :)

hello there! when is gonna be this kata available for c++ wizards like me ?