Score of Parentheses

Description

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.

Code

class Solution {
public:
    int scoreOfParentheses(string s) {
        int score = 0;
        stack<char> st;
        for(auto ch: s) {
            if(ch == '(') {
                st.push(score);
                score = 0;
            } else {
                score = st.top() + max(2 * score, 1);
                st.pop();
            }
        }
 
        return score;
    }
};

Source

• Score of Parentheses - LeetCode