Problem

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.)

Note:

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

Example1

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]].

Example2

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.)

Solution

class Solution {
public:
    
    struct cmp
    {
        bool operator()(pair<int,int> &a,pair<int,int> & b)
        {
           return a.first * a.first + a.second *a .second > b.first * b.first + b.second * b .second;
        }
    };
    vector<vector<int>> kClosest(vector<vector<int>>& points, int K) {
        
        priority_queue<pair<int,int>,vector<pair<int,int>>,cmp> pq;

        for(auto &p:points)
        {
            pq.push({p[0],p[1]});
        }

        vector<vector<int>> ret;
        while(K--)
        {
            auto p = pq.top();
            pq.pop();

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

        return ret;

    }
};