Problem Description
Given a valid parentheses string s, return the nesting depth of s. The nesting depth is the maximum number of nested parentheses.
Key Insights
- The problem requires finding the maximum depth of nested parentheses in a valid string.
- Each opening parenthesis '(' increases the current depth, while each closing parenthesis ')' decreases it.
- We can keep track of the current depth and update the maximum depth whenever we encounter an opening parenthesis.
Space and Time Complexity
Time Complexity: O(n), where n is the length of the string s. Space Complexity: O(1), since we only use a few variables to track depth and maximum depth.
Solution
To solve this problem, we can use a simple iterative approach where we traverse the string character by character. We will maintain a variable to track the current depth of parentheses and another variable to track the maximum depth encountered during the traversal. When we encounter an opening parenthesis '(', we increment the current depth. When we encounter a closing parenthesis ')', we decrement the current depth. At each increment, we will check if the current depth exceeds the maximum depth and update it accordingly.