Cfrtjryk

I am to simulate a robot moving around a 9x9 grid, the first robot starts at (0,0) and another starts at (9,9). The program is to generate random moves until they both land on the same spot.

The issue is that there is supposed to be a validation to make sure that the robot doesn't move off grid. So they should never land on coordinates like (-1,3) or (10,2). The program I wrote is below, I'm just trying to get the validation part to work but I'm not sure how to implement this problem using ONLY the methods I'm given... To clarify, I can only have the methods as written below but the methods themselves can be changed.

I thought about having the robot move first, land on an illegal coordinate but have the validateNextMove() return false and then just have it move in the reverse direction, but that's not what the assignment wants. The program needs to "look ahead and know".

So I'm thinking maybe I should have a method variable to store the next move and validate those coordinates, but I'm not sure how to do that without breaking the assignments rule of only having certain methods and variables.

Other more elegant solutions are welcome!

Thanks!

Robot.java

package assignment1;



public class Robot {



    public static void main(String args) {

        // TODO Auto-generated method stub



    }



    int x;

    int y;

    public static final int DOWN = 1;

    public static final int LEFT = 2;

    public static final int LEFT_DOWN_CORNER = 3;

    public static final int LEFT_UP_CORNER = 4;

    public static final int RIGHT = 5;

    public static final int RIGHT_DOWN_CORNER = 6;

    public static final int RIGHT_UP_CORNER = 7;

    public static final int UP = 8;





    public Robot(int x, int y) {

        this.x = x;

        this.y = y;

    }



    public int getX() {

        return x;

    }

    public void setX(int x) {

        this.x = x;

    }

    public int getY() {

        return y;

    }

    public void setY(int y) {

        this.y = y;

    }





}

MovingRobot.java

package assignment1;



import java.util.ArrayList;



public class MovingRobot extends Robot {



    public static void main(String args) {



        MovingRobot r1 = new MovingRobot(0, 0);

        MovingRobot r2 = new MovingRobot(9, 9);



        r1.move();

        System.out.println(r1.x + " " + r1.y);

        r1.move();

        System.out.println(r1.x + " " + r1.y);

        r1.move();

        System.out.println(r1.x + " " + r1.y);

        r1.move();

        System.out.println(r1.x + " " + r1.y);

        r1.move();

        System.out.println(r1.x + " " + r1.y);

        r1.move();

        System.out.println(r1.x + " " + r1.y);

        r1.move();

        System.out.println(r1.x + " " + r1.y);

        r1.move();

        System.out.println(r1.x + " " + r1.y);

        /*

         * while (sameSlot(r1, r2) == false) { r1.move(); r2.move(); }

         */

    }



    ArrayList<Integer> moves;

    int nextMove;



    public boolean validateNextMove() {

        if (x < 0 || x > 9 || y < 0 || y > 9) {

            return false;

        }



        else

            return true;



    }



    public MovingRobot(int x, int y) {

        super(x, y);

    }



    public int generateNextMove() {

        return (int) (Math.random() * 8 + 1);

    }



    public static boolean sameSlot(Robot r1, Robot r2) {

        return (r1.x == r2.x && r1.y == r2.y);

    }



    public void move() {

        switch (nextMove = generateNextMove()) {



        case 1: 

            x = x - 1;

            System.out.println(nextMove);

            //LEFT

            break;

        case 2:

            x = x - 1;

            y = y + 1;

            System.out.println(nextMove);

            //LEFT DOWN

            break;

        case 3:

            x = x - 1;

            y = y - 1;

            System.out.println(nextMove);

            //LEFT UP

            break;

        case 4:

            x = x + 1;



            System.out.println(nextMove);

            break;

            //RIGHT

        case 5:

            x = x + 1;

            y = y + 1;

            System.out.println(nextMove);

            break;

            // Right down

        case 6:

            x = x + 1;

            y = y - 1;

            System.out.println(nextMove);

            break;

            // right up

        case 7:



            y = y -1;

            System.out.println(nextMove);

            break;

            // up

        case 8:

            y = y + 1;

            System.out.println(nextMove);

            break;

            //DOWN

        }



    }



}