Given a string S consisting only of opening and closing parenthesis 'ie '(' and ')', find out the length of the longest valid(well-formed) parentheses substring.
NOTE: Length of the smallest valid substring ( ) is 2.
Example 1:
Input: S = "(()("
Output: 2
Explanation: The longest valid
substring is "()". Length = 2.
Example 2:
Input: S = "()(())("
Output: 6
Explanation: The longest valid
substring is "()(())". Length = 6.
Your Task:
You dont need to read input or print anything. Complete the function findMaxLen() which takes S as input parameter and returns the maxlength.
Expected Time Complexity:O(n)
Expected Auxiliary Space: O(1)
Constraints:
1 <= |S| <= 10^{5}

见题面

见题面