How to check if a String is balanced?

Question

I want to test if an input String is balanced. It would be balanced if there is a matching opening and closing parenthesis, bracket or brace.

example:
{} bal         


        

Answer 1

Well, roughly speaking, if it is balanced, that means your stack should be empty.

For that, you need to pop your stack when you parse a }

Additional requirement is to check that } is preceded by { or the character popped is a {.