Score of Parentheses

Problem

Compute the score of a balanced parentheses string where () scores 1, concatenation adds scores, and wrapping a group in parentheses doubles its score.

Use a stack of running scores: push a new zero on each opening bracket, and on a closing bracket add either 1 or twice the popped value to the new top. Return 0 for the empty string.

Hint

A popped score of zero means the pair was an empty (), which is worth 1.

Test cases

case 1

in: ["()"]

expected: 1

case 2

in: ["(())"]

expected: 2

case 3

in: ["()()"]

expected: 2

case 4

in: ["(()(()))"]

expected: 6

case 5

in: [""]

expected: 0

Starter codePython

def score_of_parentheses(s):
    # Your code here
    pass

5 test cases · run your code against them in the editor