1
var countGoodSubstrings = function (s) {
2
  let good = 0;
3

4
  for (let index = 0; index < s.length - 2; index++) {
5
    const subStr = s.slice(index, index + 3);
6
    const set = new Set(subStr);
7

8
    set.size === 3 && (good += 1);
9
  }
10
  return good;
11
};