1614. Maximum Nesting Depth of the Parentheses

• Time: $O(n)$
• Space: $O(1)$

C++JavaPython

class Solution {
 public:
  int maxDepth(string s) {
    int ans = 0;
    int opened = 0;

    for (const char c : s)
      if (c == '(')
        ans = max(ans, ++opened);
      else if (c == ')')
        --opened;

    return ans;
  }
};

class Solution {
  public int maxDepth(String s) {
    int ans = 0;
    int opened = 0;

    for (final char c : s.toCharArray())
      if (c == '(')
        ans = Math.max(ans, ++opened);
      else if (c == ')')
        --opened;

    return ans;
  }
}

class Solution:
  def maxDepth(self, s: str) -> int:
    ans = 0
    opened = 0

    for c in s:
      if c == '(':
        opened += 1
        ans = max(ans, opened)
      elif c == ')':
        opened -= 1

    return ans