Top K points

// using priority queue

#include <iostream>
#include <vector>
#include <queue>
#include <utility>      // std::pair

using namespace std;


struct point{
  int x;
  int y;
  int dis;
};

  //order of priority queue
//put this outside of class
  bool operator<(const point& a, const point& b) {
  return a.dis > b.dis; // '>' is mini heap; '<' is max heap (max the most important one)
  };




class solution{
  public:
  vector<pair<int, int>> topkPoints(vector<pair<int,int>> &pairs, int k){
 
  //using priority queue
  priority_queue<point> pq;

  //build the queue with k ele.
  for(int i=0;i<pairs.size();i++){
    int dis=pairs[i].first*pairs[i].first + pairs[i].second*pairs[i].second;
    point pTmp;
    pTmp.x=pairs[i].first;
    pTmp.y=pairs[i].second;
    pTmp.dis=dis;
    pq.push(pTmp);
    if(pq.size()>k)pq.pop();
  }
 
  //find the k top points
  vector<pair<int, int>> res;
  for(int i=0;i<k;i++){
    pair<int, int> tmp =make_pair(pq.top().x, pq.top().y);
    pq.pop();
    res.push_back(tmp);
  }
  return res;
  }
};
 


// To execute C++, please define "int main()"
int main() {
 
 
  vector<pair<int, int>> test;
  for(int i=0;i<10;i++){
    pair<int, int> p=make_pair(i,i);  
    test.push_back(p);
  }
 
  solution s;
  vector<pair<int,int>> res=s.topkPoints(test, 2);
  for(int i=0;i<res.size();i++){
    cout<<res[i].first<<' '<<res[i].second;
   
  }
 


  return 0;
}