@Override
public List<SearchNode<RobotPuzzle, RobotMove>> getSuccessors(
SearchNode<RobotPuzzle, RobotMove> s) {
ArrayList<SearchNode<RobotPuzzle, RobotMove>> successors =
new ArrayList<SearchNode<RobotPuzzle, RobotMove>>();
RobotPuzzle current = s.getState();
for (int i = 0; i < 4; i++) {
if (isPossibleMove(new RobotMove(i))) {
RobotPuzzle successor = new RobotPuzzle(current);
successor.performAction(new RobotMove(i));
successors.add(new SearchNode<RobotPuzzle, RobotMove>(s, new RobotMove(i), successor));
}
}
return successors;
}