Top-k-Frequent-Elements.md

Top K Frequent Solution

Question

My Solution:

class Solution {
public:
    vector<int> topKFrequent(vector<int>& nums, int k) {
        
        unordered_map<int,int> mp;
        for(int i=0;i<nums.size();i++) {
            mp[nums[i]]++;
        }

        priority_queue<pair<int,int>> pq;
        for(auto& i:mp) {
            pq.push({i.second, i.first});
        }

        vector<int> ans;
        while(k--) {
            ans.push_back(pq.top().second);
            pq.pop();
        }

        return ans;
    }
};

Complexity Analysis

Time Complexity: $O(nlogn)$

Space Complexity: $O(n)$