klaster

import java.util.*;

import java.util.ArrayList;
import java.util.Collections;

import java.util.Comparator;

class Point2D {
long id;
float x;
float y;
	float dis;
	Point2D(long a,float b,float c){
	id=a;
	x=b;
	y=c;
	dis=0;


}
	public int compareTo(Point2D a){
		if(a.dis>=this.dis)
		return 1;
		else return -1;

	}
}


class AVGComparator implements Comparator<Point2D> {
	public int compare(Point2D m1, Point2D m2) {


		if(m1.dis<m2.dis)
			return -1;
		else return 1;

	}
}

class Cluster<T> {
ArrayList<Point2D> lista;
	Cluster(){
		lista=new ArrayList<Point2D>();
	}

	public void addItem(Point2D point2d) {
		lista.add(point2d);

	}

	public void near(int idd, int top) {
	Point2D a=null;
		for(int i=0;i<lista.size();i++){
			if(lista.get(i).id==idd)
			{
				a=lista.get(i);

			}
		}
		for(int i=0;i<lista.size();i++){
			Point2D c=lista.get(i);
			float dist=presmetaj(a,c);
			c.dis=dist;

		}
		Collections.sort(lista,new AVGComparator());
		for(int i=1;i<=top;i++)
		{	String aaa=String.format("%d. %d -> %.3f",i,lista.get(i).id,lista.get(i).dis);
			System.out.println(aaa);
		}

	}

	private float presmetaj(Point2D a, Point2D c) {
		return (float) Math.sqrt((a.x-c.x)*(a.x-c.x)+(a.y-c.y)*(a.y-c.y));

	}
}


/**
 * January 2016 Exam problem 2
 */
public class ClusterTest {
  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    Cluster<Point2D> cluster = new Cluster<>();
    int n = scanner.nextInt();
    scanner.nextLine();
    for (int i = 0; i < n; ++i) {
      String line = scanner.nextLine();
      String[] parts = line.split(" ");
      long id = Long.parseLong(parts[0]);
      float x = Float.parseFloat(parts[1]);
      float y = Float.parseFloat(parts[2]);
      cluster.addItem(new Point2D(id, x, y));
    }
    int id = scanner.nextInt();
    int top = scanner.nextInt();
    cluster.near(id, top);
    scanner.close();
  }
}

// your code here