Minimum Add to Make Parentheses Valid LeetCode solution in C++

1
class Solution {
2
 public:
3
  int minAddToMakeValid(string s) {
4
    stack<char> sta;
5
    int nums = 0;
6
    for (int i = 0; i < s.size(); i++) {
7
      if (s[i] == '(') {
8
        sta.push(s[i]);
9
      } else {
10
        if (!sta.empty()) {
11
          sta.pop();
12
        } else {
13
          nums++;
14
        }
15
      }
16
    }
17
    nums += sta.size();
18
    return nums;
19
  }
20
};