973. K Closest Points to Origin

leetcode973.java

class Solution {
    public int[][] kClosest(int[][] points, int k) {
        int [][] res = new int[k][2];
        PriorityQueue<int[]> maxHeap = new PriorityQueue<>(points.length,
            new Comparator<int[]>(){                                                          
            @Override
             public int compare(int[] o1, int[]o2){
                 double d1 = distance(o1);
                 double d2 = distance(o2);
                 if(d1==d2) return 0;
                 else if(d1>d2) return 1; 
                 else return -1;    
             }
            });
        for(int[] point : points){
            maxHeap.add(point);
        }
        for(int i=0; i<k ;i++){
            res[i] = maxHeap.poll();
        }
        return res;
    }
    private double distance(int [] point){
        return Math.sqrt((point[0]*point[0]) + (point[1]*point[1]));
    }
}

// Time ==> O(NlogN)
// space ==> O(N)