leetcode 347. Top K Frequent Elements

class Solution
{
public:
vector<int> topKFrequent(vector<int>& nums, int k)
{
unordered_map<int,int> count_table;
for(auto num: nums)
{
count_table[num]++;
}
priority_queue<pair<int,int>> max_heap;
for(auto elem : count_table)
{
max_heap.emplace(make_pair(elem.second,elem.first));
}
vector<int> res;
for(int i = 0;i<k;i++)
{
res.push_back(max_heap.top().second);
max_heap.pop();
}
return res;
}
};