Given a string expression made of non-negative integers and the operators +, - and * (no spaces, no parentheses), return the results of every way of fully parenthesizing it, in any order.
"2-1-1" can be 2-(1-1) = 2 or (2-1)-1 = 0, so the answer is [0, 2] in some order- Keep duplicates: two different parenthesizations with the same value both appear
- Numbers can have several digits:
"10+5" is 15 - A string with no operator is just the number
- The expression is short (at most about 25 characters), because the number of results grows like a Catalan number