从原点找到最接近的K点

Question

我有以下问题：给定点坐标列表，将k最接近点返回到原点，返回类型应为坐标列表。 我已经处理了这段代码，但需要修复返回类型smallestkpoints，以匹配最近点方法的返回类型。 有什么想法吗？

import java.lang.Math;
import java.util.List;
import java.util.Arrays;
import java.util.Hashtable;
import java.lang.Integer;
import java.lang.Double;

public class ClosestKPoints {

    //distance to origin
    public static Double distance(Integer x, Integer y) {

        double powX = Math.pow(x, 2);
        double powY = Math.pow(y, 2);

        return (Double)(Math.sqrt(powX + powY));
    }


    public static List<List<Integer>> closestPoints(int k, List<List<Integer>> points, int all) {

        Hashtable<Double,List<Integer>> pt = new Hashtable();
        Double [] dt = new Double[all];//where we store distances later to be sorted
        List<List<Integer>> smallestKPoints;//to be used as return result


        for (int i = 0; i <points.size(); i++) {
            List<Integer> in = points.get(i);
            for (int j = 0; j < in.size() - 1; j++) {
                Integer x = in.get(j);
                Integer y = in.get(j + 1);
                pt.put(distance( x, y), points.get(i));
                dt[i] = distance(x, y);
            } 

        }

        Arrays.sort(dt);

        for (int n = 0; n < k; n++) {
            List<Integer> smallestKPoints = pt.get(dt[n]);
        }

        return smallestKPoints;

    }
}