README_EN.md

856. Score of Parentheses

中文文档

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.

Solutions

Python3

class Solution:
    def scoreOfParentheses(self, s: str) -> int:
        ans = d = 0
        for i, c in enumerate(s):
            if c == '(':
                d += 1
            else:
                d -= 1
                if s[i - 1] == '(':
                    ans += 1 << d
        return ans

Java

class Solution {
    public int scoreOfParentheses(String s) {
        int ans = 0, d = 0;
        for (int i = 0; i < s.length(); ++i) {
            if (s.charAt(i) == '(') {
                ++d;
            } else {
                --d;
                if (s.charAt(i - 1) == '(') {
                    ans += 1 << d;
                }
            }
        }
        return ans;
    }
}

C++

class Solution {
public:
    int scoreOfParentheses(string s) {
        int ans = 0, d = 0;
        for (int i = 0; i < s.size(); ++i) {
            if (s[i] == '(') {
                ++d;
            } else {
                --d;
                if (s[i - 1] == '(') {
                    ans += 1 << d;
                }
            }
        }
        return ans;
    }
};

Go

func scoreOfParentheses(s string) int {
	ans, d := 0, 0
	for i, c := range s {
		if c == '(' {
			d++
		} else {
			d--
			if s[i-1] == '(' {
				ans += 1 << d
			}
		}
	}
	return ans
}

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