1614. Maximum Nesting Depth of the Parentheses

LeetCode 原题

Given a valid parentheses string s, return the nesting depth of **s. The nesting depth is the maximum number of nested parentheses.

Constraints:

• 1 <= s.length <= 100
• s consists of digits 0-9 and characters '+', '-', '*', '/', '(', and ')'.
• It is guaranteed that parentheses expression s is a VPS.

思路

太他妈的简单了 代码直接贴上

算了还是讲一下思路，就好像让你不用max()求数组内最大的数字一样，你挨个遍历，记录最大的那个。同理，你挨个遍历括号，记录括号的最大深度就可以了

class Solution:
    def maxDepth(self, s: str) -> int:
        cur = 0
        max_num = 0
        for c in s:
            if c == '(':
                cur += 1
                max_num = max(max_num, cur)
            elif c == ')':
                cur -= 1
        return max_num

时空复杂度都是O(n)