AttractiveCritter free response answer 2

The AttractiveCritter problem from the 2011 AP Computer Science Exam is typical of free response problems that test GridWorld: The AP Computer Science Case Study. The problem requires you to extend the Critter class, determine which methods to override, and implement the entire subclass.

Review the AttractiveCritter free response problem with AP CS Tutor Brandon Horn.

AttractiveCritter

public class AttractiveCritter extends Critter
{
 public ArrayList<Actor> getActors()
 {
  ArrayList<Actor> actors = new ArrayList<Actor>();
  for (Location loc : getGrid().getOccupiedLocations())
   actors.add(getGrid().get(loc));
  actors.remove(this);
  return actors;
 }

 public void processActors(ArrayList<Actor> actors)
 {
  for (Actor a : actors)
  {
   int direction = a.getLocation().getDirectionToward(getLocation());
   Location loc = a.getLocation().getAdjacentLocation(direction);
   if (getGrid().isValid(loc) && // validity check not strictly necessary
       getGrid().get(loc) == null) // empty check necessary
    a.moveTo(loc);
  }
 }
}