Robot.java

import java.awt.Point;
import java.lang.Math;
import java.util.Scanner;
import java.io.File;
class Robot
{  
    enum Direction
    {
        N('N', 0,1),
        E('E', 1,0),
        S('S', 0,-1),
        W('W', -1,0);
        public final Point offset;
        public final char symbol;
        Direction(char symbol, int xOffset, int yOffset)
        {
            this.symbol = symbol;
            this.offset = new Point(xOffset, yOffset);
        }
        public static Direction rotate(Direction d, char c)
        {
            if(c=='L')
            {
                switch(d)
                {
                    case N:
                        return W;
                    case E:
                        return N;
                    case S:
                        return E;
                    case W:
                        return S;
                }
            }
            else if (c=='R')
            {
                switch(d)
                {
                    case N:
                        return E;
                    case E:
                        return S;
                    case S:
                        return W;
                    case W:
                        return N;
                }
            }
            return null;//throw new InvalidSymbolException(c);
        }
        public static Direction get(char c)
        {
            for(Direction d:Direction.values())
                if(d.symbol==c)
                    return d;
            return null;
        }
        //class InvalidSymbolException extends Exception
        //{
        //    public InvalidSymbolException(char c)
        //    {
        //        this.c=c;
        //    }
        //    final char c;
        //}
    }
    
    Point envMax;
    Point location;
    Direction direction;
    Robot(Point envMax, int x, int y, char c)
    {
        this.envMax=envMax;
        location = new Point(x,y);
        direction = Direction.get(c);
    }
    void rotate(char c)
    {
        direction=Direction.rotate(direction, c);
    }
    void move()
    {
        location.translate((int)direction.offset.getX(), (int)direction.offset.getY());
        //Presumably we have to clamp/wrap here.
        location.setLocation(Math.min(Math.max((int)location.getX(),0),envMax.getX()),Math.min(Math.max((int)location.getY(),0),envMax.getY()));
    }
    String getPosition()
    {
        return ""+(int)location.getX()+" "+(int)location.getY()+" "+direction.symbol;
    }
    public static void main(String[] args)throws Exception
    {
        Scanner s = new Scanner(new File(args.length>=1?args[0]:"test.txt"));
        Point envMax = new Point(s.nextInt(),s.nextInt());
        while(s.hasNext())
        {
            //Create new robot
            Robot rb = new Robot(envMax,s.nextInt(),s.nextInt(),s.next().toUpperCase().charAt(0));//Eww java scanner can't grab single char
            String path = s.next().toUpperCase();
            for(int i=0;i<path.length();i++)
            {
                char action = path.charAt(i);
                if(action=='M')
                {
                    rb.move();
                }
                else
                {
                    rb.rotate(action);
                }
            }
            System.out.println(rb.getPosition());
        }
    }
}