关于火星探测器的试题

public interface Action {
	public String getOutput(InputStream input);
}

public class ActionImpl implements Action {
	//the width and the height of each grid
	private int grid_width = 1;
	private int grid_height = 1;
	
	//the max width and the max height of the whole grids
	private int max_grid_width;
	private int max_grid_height;
	
	//the min width and the max height of the whole grids
	private int min_grid_width;
	private int min_grid_height;
	
	private String output;
	
	public ActionImpl(){
	}
	
	public ActionImpl(int min_grid_width, int min_grid_height){
		this.min_grid_height = min_grid_height;
		this.min_grid_width = min_grid_width;
	}
	
	public ActionImpl(int... args) throws Exception{
		if(args.length == 4){
			this.max_grid_width = args[0];
			this.max_grid_height = args[1];
			this.min_grid_width = args[2];
			this.min_grid_height = args[3];
		}else{
			throw new Exception("There is not enough args");
		}
	}
	
	public String getOutput(InputStream input){
		List<String> input_divided = devideInput(input);
		
		if(Integer.parseInt(input_divided.get(0).toString())<=this.min_grid_height 
				|| Integer.parseInt(input_divided.get(1).toString())<=this.min_grid_width){
			try {
				throw new Exception("you entered the uncorrect args");
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		
		this.max_grid_height = Integer.parseInt(input_divided.get(0).toString());
		this.max_grid_width = Integer.parseInt(input_divided.get(1).toString());
		
		List<Robot> robots = new ArrayList<Robot>();
		try {
			robots = generateRobots(robots, input_divided);
		} catch (Exception e) {
			e.printStackTrace();
		}

		this.output = "";
		for(int i=0;i<robots.size();i++){
			try {
				this.output += explore((Robot) robots.get(i)) + " ";
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		
		return this.output.trim();
	}
	
	private List<Robot> generateRobots(List<Robot> robots, List<String> input_divided) throws Exception{
		for(int i=2;i<input_divided.size();i=i+4){
			Robot robot = new Robot();
			robot.setX(Integer.parseInt(input_divided.get(i).toString()));
			robot.setY(Integer.parseInt(input_divided.get(i+1).toString()));
			isBeyondTheMark(robot);
			robot.setDirection(input_divided.get(i+2).toString().charAt(0));
			robot.setAction(input_divided.get(i+3).toString());
			robots.add(robot);
		}
		return robots;
	}
	
	private List<String> devideInput(InputStream input){
		Scanner scan = new Scanner(input);
		List<String> input_divided = new ArrayList<String>();
		
		while(scan.hasNext()){
			String each_input = scan.next();
			if(each_input=="stop"||each_input.equals("stop")){
				break;
			}
			input_divided.add(each_input);
		}
		
		return input_divided;
	}
	
	private String explore(Robot robot) throws Exception{
		char[] action = robot.getAction().toCharArray();
		
		for(int i=0;i<action.length;i++){
			switch(action[i]){
				case 'L': 
					turn(robot, 'L');
					break;
				case 'R':
					turn(robot, 'R');
					break;
				case 'M':
					turn(robot, 'M');
					break;
			}
		}
		return robot.getX() + " " + robot.getY() + " " + robot.getDirection();
	}
	
	private void turn(Robot robot, char direction) throws Exception{
		if(direction == 'L'){
			for(int j=0;j<Robot.directions.length;j++){
				if(robot.getDirection()==Robot.directions[j]){
					if(j==0){
						robot.setDirection(Robot.directions[3]);
					}else{
						robot.setDirection(Robot.directions[j-1]);
					}
					break;
				}
			}
		}else if(direction == 'R'){
			for(int j=0;j<Robot.directions.length;j++){
				if(robot.getDirection()==Robot.directions[j]){
					if(j==3){
						robot.setDirection(Robot.directions[0]);
					}else{
						robot.setDirection(Robot.directions[j+1]);
					}
					break;
				}
			}
		}else if(direction == 'M'){
			if(robot.getDirection()==Robot.directions[0]){
				robot.setY(robot.getY()+1);
			}else if(robot.getDirection()==Robot.directions[1]){
				robot.setX(robot.getX()+1);
			}else if(robot.getDirection()==Robot.directions[2]){
				robot.setY(robot.getY()-1);
			}else if(robot.getDirection()==Robot.directions[3]){
				robot.setX(robot.getX()-1);
			}
		}
		isBeyondTheMark(robot);
	}
	
	private void isBeyondTheMark(Robot robot) throws Exception{
		if(robot.getX()>this.max_grid_height||robot.getY()>this.max_grid_width
				||robot.getX()<this.min_grid_height||robot.getY()<this.min_grid_width){
			throw new Exception("beyond the mark");
		}
	}

	public String getOutput() {
		return output;
	}

	public void setOutput(String output) {
		this.output = output;
	}
}

public class Robot {
	public static final char[] directions = {'N', 'E', 'S', 'W'};
	
	//	the position of the robotic rover
	private int x;
	private int y;
	private char direction;

	private String action;
}

public class Main {
	public static void main(String[] args) {
		Action action = new ActionImpl();
		String output = action.getOutput(System.in);
		System.out.println(output);
	}
}