Check If a String Contains All Binary Codes of Size K LeetCode solution in JavaScript

1
/**
2
 * @param {string} s
3
 * @param {number} k
4
 * @return {boolean}
5
 */
6
var hasAllCodes = function (s, k) {
7
  if (k > s.length) {
8
    return false;
9
  }
10

11
  /* Max strings can be generated of k chars 0/1. */
12
  const max = Math.pow(2, k);
13

14
  /*
15
   * Create a set.
16
   * It will contain all unique values.
17
   */
18
  const set = new Set();
19

20
  for (let i = 0; i < s.length - k + 1; i++) {
21
    /* Generate substring of size k from index i */
22
    const substr = s.substr(i, k);
23
    set.add(substr);
24

25
    /*
26
     * if enough of unique strings are generated,
27
     * break the loop as there is no point of iterating
28
     * as we have found all necessary strings.
29
     */
30
    if (set.size === max) {
31
      return true;
32
    }
33
  }
34

35
  return set.size === max;
36
};