Loading collection data...
Collections are a way for you to organize kata so that you can create your own training routines. Every collection you create is public and automatically sharable with other warriors. After you have added a few kata to a collection you and others can train on the kata contained within the collection.
Get started now by creating a new collection.
I pass both of your mentioned cases with your solution. Clearly the issue lies within some part of your null or negation checker, but seeing your latest solution (which is correct), we may not know...