Given a balanced parentheses string S, compute the score of the string based on
the following rule:
() has score 1AB has score A + B, where A and B are balanced parentheses
strings.
(A) has score 2 * A, where A is a balanced parentheses string.
Example 1:
Input: "()" Output: 1
Example 2:
Input: "(())" Output: 2
Example 3:
Input: "()()" Output: 2
Example 4:
Input: "(()(()))" Output: 6
Note:
S is a balanced parentheses string, containing only
( and
).
2 <= S.length <= 50