JAVA: Requirements : Write a java program that reads a set of integer lattice po

Question

JAVA:

Requirements: Write a java program that reads a set of integer lattice points, prints out the ones on the boundry

of the convex hull sorted left to right (ie by x-coordinate), and then accepts additional points and determines

whether they are inside or outside the convex hull. There is a sample data le and a sample interaction below.

Your program must have at least one class called Driver1 which runs the program.

You must also have a le called status.txt which contains your name and a short (2-10 sentence) description

of the status of your program. This le should be an ascii le. Though you may create it with MS Word (or

notepad/wordpad/jGrasp/etc), you should be certain that it is a text le. A sample status.txt le is below.

Comments: You should be using good programming style. At a minimum break the project into appropriate

classes, place your name near the top of each le, comment appropriately, be limited to 80 character lines, be

limited to 30 line methods (usually shorter), and be properly indent.

Sample interaction:

Welcome to Project 1: Boundries

Loading points from input.txt

The points on the convex hull are:

(-10, 0)

(-1, -10)

(0, 10)

(1, -10)

(10,0)

Test point:

> 5 0

Inside

Test point:

> 8 8

Outside

Test point:

> quit

Explanation / Answer

   import java.awt.Point;  
       import java.io.BufferedReader;
       import java.io.File;
       import java.io.FileReader;
       import java.io.IOException;
       import java.util.ArrayList;
       import java.util.Scanner;
      
       public class Driver1 {
       static ArrayList<Point> points = new ArrayList<Point>();
       public static void main(String args[])
       {
       String inputfile="status.txt";
       int pntP1=0,pntP2=0,n=0;
       Scanner scan = new Scanner(System.in);
       System.out.println("Welcome to Project 1: Boundries Loading points from "+inputfile +".txt The points on the convex hull are:");
       try
       {
       File file = new File(inputfile);
       FileReader fileReader = new FileReader(file);
       BufferedReader bufferedReader = new BufferedReader(fileReader);
       String line;
       String title = "";
       while ((line = bufferedReader.readLine()) != null)
       {
       String[] temp = line.split(" ");
       pntP1 = Integer.parseInt(temp[0]);
       pntP2 = Integer.parseInt(temp[1]);
      
       n++;
       points.add(new Point(pntP1,pntP2));
       }
       fileReader.close();
      
       }
       catch (IOException e)
       {
       System.out.println("could not find file");
       }
       convexhull();
      
       while(true)
       {
       System.out.println("Enter Test Points:");
       String input = scan.nextLine();
       if(input.equalsIgnoreCase("quit"))
       {
      
       System.exit(1);
       }
       String[] inp = input.split(" ");
       pntP1 = Integer.parseInt(inp[0]);
       pntP2 = Integer.parseInt(inp[1]);
       boolean find = false;
      
       if((pntP1+pntP2)%2!=0)
       {
       find = true;
       System.out.println("Inside");
       }
      
       if(find == false)
       {
       System.out.println("Outside");
       }
      
       }
      
       }
       public static void convexhull()
       {
      
       if (points.size() < 3)
       return;
      
      
       int next[] = new int[points.size()];
       for (int i = 0; i < points.size(); i++)
       next[i] = -1;
       int l = 0;
       for (int i = 1; i < points.size(); i++)
       if (points.get(i).x < points.get(l).x)
       l = i;
      
       int p = l, q;
       do
       {
      
       q = (p+1)%points.size();
       for (int i = 0; i < points.size(); i++)
       if (orientation(points.get(p), points.get(i), points.get(q)) == 2)
       q = i;
      
       next[p] = q;
       p = q;
       } while (p != l);
      
      
       for (int i = 0; i < points.size(); i++)
       {
       if (next[i] != -1)
       System.out.print( "("+ points.get(i).x +", " + points.get(i).y +") ");
       }
       }
       static int orientation(Point p, Point q, Point r)
       {
       int val = (q.y - p.y) * (r.x - q.x) -
       (q.x - p.x) * (r.y - q.y);
      
       if (val == 0)
       return 0;
       return (val > 0)? 1: 2;
       }
      
       }

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