K Closest Points to Origin

K Closest Points to Origin

We have a list of points on the plane.  Find the K closest points to the origin (0, 0).

(Here, the distance between two points on a plane is the Euclidean distance.)

You may return the answer in any order.  The answer is guaranteed to be unique (except for the order that it is in.)

 

Example 1:

Input: points = [[1,3],[-2,2]], K = 1
Output: [[-2,2]]
Explanation: 
The distance between (1, 3) and the origin is sqrt(10).
The distance between (-2, 2) and the origin is sqrt(8).
Since sqrt(8) < sqrt(10), (-2, 2) is closer to the origin.
We only want the closest K = 1 points from the origin, so the answer is just [[-2,2]].

Example 2:

Input: points = [[3,3],[5,-1],[-2,4]], K = 2
Output: [[3,3],[-2,4]]
(The answer [[-2,4],[3,3]] would also be accepted.)

 

Note:

1. 1 <= K <= points.length <= 10000
2. -10000 < points[i][0] < 10000
3. -10000 < points[i][1] < 10000

 class Solution {

public:

    vector<vector<int>> kClosest(vector<vector<int>>& points, int K) {

        priority_queue< pair<int,pair<int,int> >,vector<pair<int,pair<int,int> > >,greater<>> q;

            for(auto p:points)

            {

                q.push({p[0]*p[0]+p[1]*p[1],{p[0],p[1]}});

            }

        vector<vector<int> > ans;

        while(!q.empty()&&K>0)

        {

             auto p=q.top();

            q.pop();

             ans.push_back({p.second.first,p.second.second});

            --K;

        }

        return ans;

    }

};