leetcode

0 class Solution {

1 public:

2 vector<string> watchedVideosByFriends(vector<vector<string>> &watchedVideos, vector<vector<int>> &adj,

3 int id, int level) {

4 int n = adj.size();

5 vector<bool> visited(n, false);

6 queue<int> q;

7

8 q.push(id);

9 visited[id] = true;

10 for (int lvl = 0; lvl != level; lvl++) {

11 for (int k = q.size(); k > 0; k--) {

12 int id = q.front();

13 q.pop();

14 for (int c : adj[id]) {

15 if (!visited[c]) {

16 visited[c] = true;

17 q.push(c);

18 }

19 }

20 }

21 }

22

23 unordered_map<string, int> freq;

24 vector<pair<int, string>> vec;

25 vector<string> res;

26

27 for (; !q.empty(); q.pop())

28 for (auto &st : watchedVideos[q.front()])

29 freq[st]++;

30

31 for (auto &[k, v] : freq)

32 vec.push_back({v, k});

33 sort(vec.begin(), vec.end());

34 for (auto &[_, title] : vec)

35 res.push_back(title);

36 return res;

37 }

38 };