CodeWars: Permutations Solution

1function swap(arr, i, j) {
2  ;[arr[i], arr[j]] = [arr[j], arr[i]]
3}
4
5function genPerms(chars, left, right, set) {
6  if (left === right) {
7    set.add(chars.join(""))
8  } else {
9    for (let i = left; i <= right; i++) {
10      swap(chars, left, i)
11      genPerms(chars, left + 1, right, set)
12      swap(chars, left, i)
13    }
14  }
15}
16
17function permutations(string) {
18  const N = string.length
19  const chars = string.split("")
20  const set = new Set()
21  genPerms(chars, 0, N - 1, set)
22  return Array.from(set)
23}