And your "solution" (the latest one that I can see) seems way too simple and incorrect. It fails for even the first test that's mentioned in the description:

Expected: { '1': [ 'C' ], '2': [ 'A', 'B', 'D' ] }, instead got: { '1': [ 'A', 'B', 'C' ], '2': [ 'A', 'B', 'D' ] } 

Make sure to read the description carefully to understand what it's asking for. If you're stuck, try debugging it: https://docs.codewars.com/training/troubleshooting

It's probably not correct then.