Topcoder SRM 646 Div2 500 problem

I was not ablet to solve this promblem when participated in the contest.

and I see other people's source and finally i rewrite and sovle this problem using Queue

my code is



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package srm646;

import java.util.LinkedList;
import java.util.Queue;


public class TheGridDivTwo {

 public static void main(String[] args) {
  
  int [] x = {5, 1, -1, 4, 1, 3, 5, 2, 1, -1, 4, 2, -1, -1, 0, -2, 3, 3, 1, 2, 4, 4, 1, 2, 3, 2, 3, 5, -1, 0, 1, 5, 4, -2, 5, 0, 0, 4, -2, 0, 3};
  int [] y = {3, 4, 2, 1, -2, 4, -2, 0, 1, -1, 0, 2, 5, 1, 3, 4, -2, 1, 2, 5, 2, -2, 5, -2, 3, 3, 5, 5, 0, 4, 0, 1, 4, 0, 4, -2, 2, -1, -2, 1, 0};
  int k = 11;
  
  TheGridDivTwo two = new TheGridDivTwo();
  System.out.println(two.find(x, y, k));
 }
 
 public int find(int[] x, int[] y, int k){
  Queue<Point> queue= new LinkedList<Point>();
  int[][] visited = new int[2001][2001];
  for(int i=0;i<x.length; i++){
   visited[x[i]+1000][y[i]+1000] = 1;
  }
  if(x.length == 0){
   return k;
  }
  
  Point start = new Point(0, 0, k);
  visited[1000][1000] = 1;
  queue.add(start);
  int maxX = 0;
  while(!queue.isEmpty()){
   
   Point point  = queue.poll();
   if(point.sec <= 0){
    continue;
   }
   
   Point right = new Point(point.x + 1, point.y, point.sec-1);
   Point top = new Point(point.x , point.y + 1,  point.sec-1);
   Point bottm = new Point(point.x , point.y - 1, point.sec-1);
   Point left = new Point(point.x - 1, point.y, point.sec-1);
   
   // right
   if(!isVisited(right,  visited) ){
    queue.add(right);
    maxX = Math.max(maxX, point.x +1);
   }
   // top
   if(!isVisited(top, visited) ) queue.add(top);   
   
   // bottom
   if(!isVisited(bottm,  visited)) queue.add(bottm);
   
   // left
   if(!isVisited(left ,visited)) queue.add(left);
  }
  
  return maxX;
  
 }
 
 public boolean isVisited(Point point,  int[][] visited){
  
  int x = point.x;
  int y = point.y;
  int sec = point.sec;
  
  if((sec + x < 0) || visited[x+ 1000][y+1000] == 1){
   return true;
  }
  
  visited[x+ 1000][y+1000] = 1;
  
  return false;
 }  
 
 class Point{
  private int x;
  private int sec;
  private int y;

  public Point(int x, int y, int sec) {

   this.x = x;
   this.y = y;
   this.sec = sec;
  }
 }

}

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