K closest points to origin

#define pv pair<int,pair<int,int>>
class Solution {
public:
    vector<vector<int>> kClosest(vector<vector<int>>& points, int k) {
      priority_queue<pv,vector<pv>,greater<pv>> pq;   //find distnace of all nodes from origin or other point if given as source
      for(int i=0;i<points.size();i++){               //and push it into min heap along with it's cordinates
         int a=points[i][0],b=points[i][1];
         pq.push(make_pair(a*a+b*b,make_pair(a,b)));
      }
      vector<vector<int>> res;
      for(int i=0;i<k;i++){    //pop k cordinates from min_heap which will be closest to origin
          pv temp=pq.top();
          pq.pop();
          vector <int> t;
          t.push_back(temp.second.first);
          t.push_back(temp.second.second);
          res.push_back(t);
          t.clear();
      }
        return res;
    }
};