Minimize Hamming Distance After Swap Operations LeetCode solution in JavaScript

1
var minimumHammingDistance = function (source, target, allowedSwaps) {
2
  const n = source.length;
3

4
  const uf = {};
5
  const sizes = {};
6
  const members = {};
7

8
  // initial setup
9
  for (let i = 0; i < n; i++) {
10
    const srcNum = source[i];
11

12
    uf[i] = i;
13
    sizes[i] = 1;
14
    members[i] = new Map();
15
    members[i].set(srcNum, 1);
16
  }
17

18
  function find(x) {
19
    if (uf[x] != x) uf[x] = find(uf[x]);
20
    return uf[x];
21
  }
22

23
  function union(x, y) {
24
    const rootX = find(x);
25
    const rootY = find(y);
26

27
    if (rootX === rootY) return;
28

29
    if (sizes[rootX] > sizes[rootY]) {
30
      uf[rootY] = rootX;
31
      sizes[rootX] += sizes[rootY];
32

33
      for (const [num, count] of members[rootY]) {
34
        if (!members[rootX].has(num)) members[rootX].set(num, 0);
35
        members[rootX].set(num, members[rootX].get(num) + count);
36
      }
37
    } else {
38
      uf[rootX] = rootY;
39
      sizes[rootY] += sizes[rootX];
40

41
      const num = source[x];
42

43
      for (const [num, count] of members[rootX]) {
44
        if (!members[rootY].has(num)) members[rootY].set(num, 0);
45
        members[rootY].set(num, members[rootY].get(num) + count);
46
      }
47
    }
48
  }
49

50
  for (const [idx1, idx2] of allowedSwaps) {
51
    union(idx1, idx2);
52
  }
53

54
  let mismatches = 0;
55

56
  for (let i = 0; i < n; i++) {
57
    const srcNum = source[i];
58
    const tarNum = target[i];
59

60
    const group = find(i);
61

62
    if (members[group].has(tarNum)) {
63
      members[group].set(tarNum, members[group].get(tarNum) - 1);
64
      if (members[group].get(tarNum) === 0) members[group].delete(tarNum);
65
    } else {
66
      mismatches++;
67
    }
68
  }
69

70
  return mismatches;
71
};