Given a number 'n', generate all possible well-formed (balanced) parentheses strings of length 2*n. For instance, if n=3, you need to create all valid combinations like '((()))', '(()())', etc.

Find the length of the longest substring within a given string that contains no repeating characters. The substring must be contiguous.

You're given a sorted array that has been rotated, and a target value. Find the index of the target value in the rotated array, or return -1 if it's not present.