algorithms/minimumEditsParanthesis.java at master · kjayashr/algorithms · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
class Solution {
    public int minAddToMakeValid(String S) {
      Stack<Character> stack = new Stack<Character>();
        int count = 0;
      for(int i = 0 ; i < S.length(); i++)
      {
          if(S.charAt(i) == '(')
              stack.push(')');
          else if(S.charAt(i) == '[')
              stack.push(']');
          else if(S.charAt(i)== '{')
              stack.push('}');
          else
          {

            if(stack.isEmpty()) count ++;

                else if(!stack.isEmpty() && stack.pop() != S.charAt(i))
                count ++;

          }


      }
        while(!stack.isEmpty())
        {
            stack.pop();
            count++;
        }

        return count;
}
}
///
/*
class Solution {
    public int minAddToMakeValid(String S) {
        int ans = 0, bal = 0;
        for (int i = 0; i < S.length(); ++i) {
            bal += S.charAt(i) == '(' ? 1 : -1;
            // It is guaranteed bal >= -1
            if (bal == -1) {
                ans++;
                bal++;
            }
        }

        return ans + bal;
    }
}

*/