You're on a rectangular grid and you have to light up all the cells. For that, you need to put some lights in dark cells (so no light should illuminate another). The lights that you have illuminate in the four directions from wall to wall. And there are constraints: some walls must have a given number of lights close to them.
The grid will be represented...
CheckiO Extensions allow you to use local files to solve missions. More info in a blog post.
In order to install CheckiO client you'll need installed Python (version at least 3.8)
Install CheckiO Client first:
pip3 install checkio_client
Configure your tool
checkio --domain=py config --key=
Sync solutions into your local folder
(in beta testing) Launch local server so your browser can use it and sync solution between local file end extension on the fly. (doesn't work for safari)
checkio serv -d
Alternatevly, you can install Chrome extension or FF addon
checkio install-plugin --ff
checkio install-plugin --chromium