import java.util.*;

// Game of Life!

public class Seating
{
    public static final String WORLD_DATA = "input.txt";

    public static void main (String[] args)
    {
        boolean debug = false;
        boolean verify = false;

        for (int i = 0; i < args.length; i++)
        {
            if ("-help".equals(args[i]))
            {
                System.out.println("Usage: [-verify] [-debug] [-help]");

                System.exit(0);
            }

            if ("-debug".equals(args[i]))
                debug = true;

            if ("-verify".equals(args[i]))
                verify = true;
        }

        if (verify)
        {
            Verifier theVerifier = new Verifier(debug);

            if (theVerifier.verify())
                System.out.println("Verified ok!");
            else
                System.out.println("Verify failed!");

            System.exit(0);
        }

        Grid theWorld = new Grid(WORLD_DATA, debug);
        boolean found = false;
        Vector<Grid> previous = new Vector<Grid>();

        previous.add(theWorld.snapshot());

        while (!found)
        {
            theWorld.evolve();

            if (previous.contains(theWorld))
                found = true;
            else
                previous.add(theWorld.snapshot());
        }
    }
}
@@ -86,21 +86,21 @@
  String 
-WORLD
+PLANE
 _DATA = 
@@ -921,21 +921,21 @@
 Grid the
-World
+Plane
  = new G
@@ -942,13 +942,13 @@
 rid(
-WORLD
+PLANE
 _DAT
@@ -975,19 +975,22 @@
 oolean f
-oun
+inishe
 d = fals
@@ -1004,96 +1004,8 @@
     
-Vector%3CGrid%3E previous = new Vector%3CGrid%3E();%0A%0A        previous.add(theWorld.snapshot());%0A
 %0A   
@@ -1018,19 +1018,22 @@
 hile (!f
-oun
+inishe
 d)%0A     
@@ -1049,24 +1049,43 @@
         
-theWorld
+int changedSeats = thePlane
 .evolve(
@@ -1108,35 +1108,25 @@
 if (
-previous.contains(theWorld)
+changedSeats == 0
 )%0A  
@@ -1144,11 +1144,14 @@
    f
-oun
+inishe
 d = 
@@ -1160,32 +1160,26 @@
 ue;%0A        
-    else
+%7D%0A
 %0A           
@@ -1179,60 +1179,72 @@
     
-        previous.add(theWorld.snapshot());%0A        %7D
+System.out.println(%22Occupied seats: %22+thePlane.occupiedSeats());
 %0A   

Update Seating.java