1614. Maximum Nesting Depth of the Parentheses

扫描线 O(n) time O(1) space

class Solution {
public:
    int maxDepth(string s) {
        int res = 0, cnt = 0;
        for (char c : s) {
            cnt += c == ')' ? -1 : (c == '(');
            res = max(res, cnt);
        }
        return res;
    }
};