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.
That's actually quite smart
Also, there is a way to use few memory by using stack size of len(str)/2 (and check for overflow)
Each call follows to execution of all four operators, then select result. Performace issue