BlueJ Java Puzzle中的move方法的条件语句

问题描述

我必须完成一些方法才能跨房间退出。 如果您踩到每个点，它将打开或关闭力场。 我将如何为move方法编写条件语句？ 我的一直在告诉我，即使我应该能够采取行动，我也无法做到。

我了解如何移动，但不了解如何格式化条件语句以允许我越过关闭的障碍（错误）而打开其他障碍（正确）。 也就是说，如果红色障碍打开了，但黄色关闭了，我应该可以移动到黄色，但事实并非如此，因为它告诉我路径被阻塞了。

 /*
 * 
 * This class allows a user to walk around in a virtual 3x3 room 
 * and solve a puzzle.
 * 
 * The room has nine locations with the following (x, y) coordinates.
 * 
 *                      (0, 0)  (1, 0)  (2, 0)
 *                      (0, 1)  (1, 1)  (2, 1)
 *                      (0, 2)  (1, 2)  (2, 2)
 *                      
 * The user starts at location (1, 2).  Directly across the room from the 
 * user is a door.  The door may be blocked by 0, 1, or 2 force fields.  
 * The frame of the door identifies which force field is currently blocking 
 * it: a red frame means that only the red force field is on, a yellow frame 
 * means that only the yellow force field is on, an orange frame means that 
 * both force fields are on, and a green frame means that both fields are off. 
 * 
 * Depending where the user steps in the room one of the force fields will 
 * either turn on or off. The goal of the puzzle is to cross the room (i.e., 
 * reach position (1,0)) facing the door with both force fields off (i.e., a 
 * green frame).  
 * 
 * The constructor and the methods of this class are incomplete.  The comments 
 * tell you what is missing.  You do not need to add any fields to this class.  
 * You do not need to change any of the other classes in this project.
 */

public class Puzzle
{

    //Your current xy position in the room
    private int xPosition;
    private int yPosition;

    //Boolean variables that tell you whether or not the red and yellow
    //force fields are currently turned on (true) or off (false).
    private boolean yellowField;
    private boolean redField;

    private View view;

    public Puzzle()
    {

        /*
         * Finish: Initialize xPosition and yPosition to reflect that your 
         * initial position in the puzzle is (1,2) and that both force fields 
         * are initially off.
         */
        xPosition = 1;
        yPosition = 2;
        yellowField = false;
        redField = false;
        view = new View();
        view.display(xPosition, yPosition, yellowField, redField);
    }

    public void moveForward() 
    { 
        /*
         * Finish: Implement this method that moves you forward in the room
         * if there is not a wall blocking you.  Otherwise print a message
         * alerting the user that this move is not permitted now.
         * 
         * If the move is allowed then you should call toggleFields() and
         * view.display(xPosition, yPosition, yellowField, redField) afterward.
         */

     }

    public void moveBackward()
    {
        /*
         * Finish: Implement this method that moves you backward in the room
         * if there is not a wall blocking you.  Otherwise print a message
         * alerting the user that this move is not permitted now.
         * 
         * If the move is allowed then you should call toggleFields() and
         * view.display(xPosition, yPosition, yellowField, redField) afterward.
         */

        if (yellowField)
        {
            if (yellowField == false)
                {
                    yPosition += 1;
                    toggleFields();
                    view.display(xPosition, yPosition, yellowField, redField);
                }
            else
                {
                    System.out.println("Your path is blocked pick another move");
                }
        }
        else
        {
            if (redField == false)
                {
                    yPosition += 1;
                    toggleFields();
                    view.display(xPosition, yPosition, yellowField, redField);
                }
            else
                {
                    System.out.println("Your path is blocked pick another move");
                }
        }
    }

    public void moveRight()
    {

    }

    public void moveLeft()
    {
        /*
         * Finish: Implement this method that moves you to the left in the room
         * if there is not a wall blocking you.  Otherwise print a message
         * alerting the user that this move is not permitted now.
         * 
         * If the move is allowed then you should call toggleFields() and
         * view.display(xPosition, yPosition, yellowField, redField) afterward.
         * 
         */

    }

    private void toggleFields()
    {
        /*
         * Finish: Implement this method that turns a field on or off depending 
         * on where you step.  The following table describes the coordinate system 
         * and the effect of stepping in a particular location.
         * 
         * The x coordinate of a location is its row number, and the y coordinate 
         * is its column number.
         * 
         *     0   1   2  
         *  ------------
         *  0| r   r   r
         *   |
         *  1| r   y   r
         *   |
         *  2| y   y   y
         *  
         *  
         *  By stepping in a location labeled 'r' the red force field will turn 
         *  'on' if it is currently 'off' and 'off' if it is currently turned 'on'.
         *  
         *  By stepping in a location labeled 'y' the yellow force field will turn 
         *  'on' if it is currently 'off' and 'off' if it is currently turned 'on'.
         */
        if(redField)
        {
            if (redField == true)
            {
                redField = false;
            }
            else 
            {
                redField = true;
            }
        }
        else
        {
            if (yellowField == true)
            {   
                yellowField = false;
            }
            else
            {
                yellowField = true;
            }
        }
    }  

    public void walkthrough()
    {
        /*
         * Extra Credit:  Provide a sequence of calls to moveForward(), moveLeft(), 
         * moveRight(), and moveBackward() that solves the puzzle.  The puzzle is
         * solved if these moves take the user from location (1, 2) to location (1, 0)
         * facing a green door.
         * 
         */   
    }
}