1614. Maximum Nesting Depth of the Parentheses 

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
class Solution {
    public int maxDepth(String s) {
        int maxDepth = 0;

        int leftBrackets = 0;
        for (int i = 0; i < s.length(); i++) {
            char c = s.charAt(i);
            if (c == '(') {
                leftBrackets++;
                maxDepth = Math.max(maxDepth, leftBrackets); // 题目保证了表达式 s 是有效的括号表达式
            } else if (c == ')') {
                leftBrackets--;
            }
        }

        return maxDepth;
    }
}

References

1614. Maximum Nesting Depth of the Parentheses