1
var balancedString = function (s) {
2
  let output = Infinity;
3

4
  let map = { Q: 0, W: 0, E: 0, R: 0 };
5

6
  for (let letter of s) {
7
    map[letter]++;
8
  }
9

10
  let valueGoal = s.length / 4;
11

12
  let remainder = 0;
13

14
  let count = 4;
15

16
  for (let [key, val] of Object.entries(map)) {
17
    if (val > valueGoal) {
18
      remainder = remainder + (val - valueGoal);
19
    }
20

21
    if (val === valueGoal || val < valueGoal) {
22
      map[key] = -Infinity;
23
      count--;
24
    }
25
  }
26

27
  if (remainder === 0) {
28
    return 0;
29
  }
30

31
  let left = 0;
32

33
  let right = 0;
34

35
  while (right < s.length) {
36
    if (map[s[right]] !== -Infinity) {
37
      map[s[right]]--;
38

39
      if (map[s[right]] === valueGoal) {
40
        count--;
41
      }
42
    }
43

44
    while (count === 0) {
45
      output = Math.min(output, right - left + 1);
46

47
      if (map[s[left]] !== -Infinity) {
48
        map[s[left]]++;
49

50
        if (map[s[left]] > valueGoal) {
51
          count++;
52
        }
53
      }
54
      left++;
55
    }
56

57
    right++;
58
  }
59

60
  return output;
61
};