leetcode

Solution to some Leetcode problems written in C++

git clone git://git.dimitrijedobrota.com/leetcode.git

1722.cpp (1240B)

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 };