题目链接

973. 最接近原点的 K 个点

思路

使用优先队列处理前k大问题

代码

class Solution {
    class Node{
        int x;
        int y;
        double distance;
    }

    public int[][] kClosest(int[][] points, int k) {
        int[][] result = new int[k][2];
        PriorityQueue<Node> queue = new PriorityQueue<>(new Comparator<Node>() {
            @Override
            public int compare(Node o1, Node o2) {
                return Double.compare(o2.distance, o1.distance);
            }
        });

        for(int i = 0; i < points.length; i++){
            Node node = new Node();
            node.x = points[i][0];
            node.y = points[i][1];
            node.distance = Math.sqrt(Math.pow(node.x, 2) + Math.pow(node.y, 2));
            queue.add(node);
            if(queue.size() > k){
                queue.poll();
            }
        }

        for(int i = 0; i < k; i++){
            Node node = queue.poll();
            result[i][0] = node.x;
            result[i][1] = node.y;
        }

        return result;
    }
}