leetcode

0 class UnionFind {

1 int n, cnt = n;

2 vector<int> root, size;

3

4 public:

5 UnionFind(int n) : n(n), root(n), size(n, 1) { iota(root.begin(), root.end(), 0); }

6

7 int find(int x) {

8 while (x != root[x])

9 x = root[x] = root[root[x]];

10 return x;

11 }

12

13 void join(int x, int y) {

14 x = find(x), y = find(y);

15 if (x != y) {

16 if (size[x] > size[y]) swap(x, y);

17 root[x] = y;

18 size[y] += size[x];

19 cnt--;

20 }

21 }

22

23 int count() { return cnt; }

24 bool connected(int x, int y) { return find(x) == find(y); }

25 };

26

27 class Solution {

28 public:

29 int minimumHammingDistance(vector<int> &source, vector<int> &target, vector<vector<int>> &allowedSwaps) {

30 int n = source.size();

31 UnionFind uf(n);

32

33 for (auto &s : allowedSwaps)

34 uf.join(s[0], s[1]);

35

36 vector<unordered_map<int, int>> vus(n);

37 for (int i = 0; i < n; i++) {

38 int pos = uf.find(i);

39 vus[pos][target[i]]++;

40 vus[pos][source[i]]--;

41 }

42

43 int res = 0;

44 for (int i = 0; i < n; i++)

45 for (auto [_, val] : vus[i])

46 res += abs(val);

47

48 return res / 2;

49 }

50 };