692. Top K Frequent Words
https://leetcode.com/problems/top-k-frequent-words/description/
class Solution { public: vector<string> topKFrequent(vector<string>& words, int k) { unordered_map<string, int> freq; for (auto & w : words) freq[w]++; priority_queue<pair<int,string>> q; for (auto & f : freq) { q.push({-f.second, f.first}); if (q.size() > k) q.pop(); } vector<string> res; while (!q.empty()) { res.push_back(q.top().second); q.pop(); } reverse(res.begin(), res.end()); return res; } };