思路

利用优先队列进行排序，然后利用multiset对count进行排序，最后收集k个高频元素就行

代码

class Solution {
public:vector<int> topKFrequent(vector<int>& nums, int k) {priority_queue<int> pq;for(int i = 0; i < nums.size(); i++){pq.push(nums[i]);}multimap<int, int > myMap;while(!pq.empty()){int count = 0;int value = pq.top();while(!pq.empty() && pq.top() == value){pq.pop();count++;}pair<int, int> p = {count, value};myMap.insert(p);}vector<int> res;for(auto it = myMap.rbegin(); k-- ; it++){res.push_back(it->second);}return res;}
};