Score of parentheses

class Solution:
    def scoreOfParentheses(self, s: str) -> int:
        stack = [0]

        for x in s:
            if x == '(':
                stack.append(0)
            else:
                v = stack.pop()
                stack[-1] += max(2 * v, 1)

        return stack.pop()

Score of Parentheses

Difficulty: Medium

Given a balanced parentheses string s, return the score of the string.

The score of a balanced parentheses string is based on the following rule:

  • "()" has score 1.
  • AB 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: s = "()"
Output: 1

Example 2:

Input: s = "(())"
Output: 2

Example 3:

Input: s = "()()"
Output: 2

 

Constraints:

  • 2 <= s.length <= 50
  • s consists of only '(' and ')'.
  • s is a balanced parentheses string.