public class Solution
extends Object
921 - Minimum Add to Make Parentheses Valid\.
Medium
A parentheses string is valid if and only if:
* It is the empty string,
* It can be written as `AB` (`A` concatenated with `B`), where `A` and `B` are valid strings, or
* It can be written as `(A)`, where `A` is a valid string.
You are given a parentheses string `s`. In one move, you can insert a parenthesis at any position of the string.
* For example, if `s = "()))"`, you can insert an opening parenthesis to be `"( **( **)))"` or a closing parenthesis to be `"())** )** )"`.
Return _the minimum number of moves required to make_ `s` _valid_.
**Example 1:**
**Input:** s = "())"
**Output:** 1
**Example 2:**
**Input:** s = "((("
**Output:** 3
**Constraints:**
* `1 <= s.length <= 1000`
* `s[i]` is either `'('` or `')'`.