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.
got it. thanks.
it goes to negative first and triggers:
if cnt < 0: return False
I did almost the same thing.
What for this input?
valid_parentheses(")(")
It is not valid, but the counter i zero.
I think you have to break the loop if closing bracket comes before opening bracket.