roadcourse.java

Java程序设计(美) David D. Riley著 机械工业出版社 书籍配套 代码

import javax.swing.JFrame;
import java.awt.Color;
public class RoadCourse  {
    private char[][] course = {{' ', ' ', ' ', ' ', ' ', 'X', ' ', ' ', ' ', ' ', ' ', ' ', 'X'},
                              {' ', ' ', ' ', ' ', ' ', 'X', ' ', ' ', ' ', ' ', ' ', ' ', ' '},
                              {'X', 'X', 'X', ' ', ' ', 'X', ' ', ' ', 'X', ' ', ' ', ' ', ' '},
                              {' ', ' ', ' ', ' ', ' ', 'X', ' ', ' ', 'X', ' ', ' ', ' ', ' '},
                              {' ', ' ', ' ', ' ', ' ', 'X', ' ', ' ', 'X', 'X', 'X', ' ', ' '},
                              {' ', ' ', 'X', 'X', 'X', ' ', ' ', ' ', 'X', ' ', ' ', ' ', ' '},
                              {' ', ' ', 'X', 'X', ' ', ' ', ' ', ' ', 'X', ' ', ' ', ' ', ' '},
                              {' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', 'X', ' ', ' ', ' ', 'X'},
                              {' ', ' ', ' ', ' ', ' ', ' ', ' ', 'X', 'X', 'X', ' ', ' ', ' '},
                              {' ', ' ', 'X', 'X', 'X', ' ', ' ', 'X', ' ', 'X', ' ', ' ', ' '}};
                              
    private boolean[][] hasRobot;
                            
    private JFrame window;

    public RoadCourse() {
        Barrier barrier;
        window = new JFrame("Robot Driving Road Course");
        window.setBounds(20, 20, 13*72, 10*72);
        window.getContentPane().setLayout(null);
        window.setVisible(true);
        window.getContentPane().setBackground(Color.white);
        hasRobot = new boolean[10][13];
        for (int row=0;  row != 10;  row++) {
            for (int col=0;  col != 13;  col++) {
                hasRobot[row][col] = false;
                if (course[row][col] != ' ') {
                    barrier = new Barrier();
                    barrier.setLocation(col*72, row*72);
                    window.getContentPane().add(barrier, 0);
                }
            }
        }
        window.getContentPane().repaint();
    }
    
    /** pre:    isAvailable(0, 0)  and  robo.getParent()==null
     *  post:   robo is placed on window and robo.getX()==0 and robo.getY()==0
     *          and  hasRobot[0][0]  and  hasRobot[0][1]
     *          and  hasRobot[1][0]  and  hasRobot[1][1] 
     */
    public void placeRobotOnRoad(Robot robo)  {
        robo.setLocation(0, 0);
        window.getContentPane().add(robo);
        robo.repaint();
        hasRobot[0][0] = true;
        hasRobot[0][1] = true;
        hasRobot[1][0] = true;
        hasRobot[1][1] = true;
    }
    
    /** post:   result ==  1 <= r <= 8  and  0 <= c <= 11
     *                     and  not hasRobot[r-1][c]   and   not hasRobot[r-1][c+1]
     *                     and  course[r-1][c]==' '  and course[r-1][c+1]==' ' 
     */
    public boolean canMoveUp(int r, int c)  {
        return 1<=r && r<=8 && 0<=c && c<=11
                && !hasRobot[r-1][c] && !hasRobot[r-1][c+1]
                && course[r-1][c]==' ' && course[r-1][c+1]==' ';
    }
    
    /** post:   result ==  0 <= r <= 8  and  0 <= c <= 10
     *                     and  not hasRobot[r][c+2]   and   not hasRobot[r+1][c+2] 
     *                     and  course[r][c+2]==' '  and course[r+1][c+2]==' ' 
     */
    public boolean canMoveRight(int r, int c)  {
        return 0<=r && r<=8 && 0<=c && c<=10
                && !hasRobot[r][c+2] && !hasRobot[r+1][c+2]
                && course[r][c+2]==' ' && course[r+1][c+2]==' ';
    }
    
    /** post:   result ==  0 <= r <= 7  and  0 <= c <= 11
     *                     and  not hasRobot[r+2][c]   and   not hasRobot[r+2][c+1] 
     *                     and  course[r+2][c]==' '  and course[r+2][c+1]==' ' 
     */
    public boolean canMoveDown(int r, int c)  {
        return 0<=r && r<=7 && 0<=c && c<=11
                && !hasRobot[r+2][c] && !hasRobot[r+2][c+1]
                && course[r+2][c]==' ' && course[r+2][c+1]==' ';
    }
    
    /** post:   result ==  0 <= r <= 8  and  1 <= c <= 11
     *                     and  not hasRobot[r][c-1]   and   not hasRobot[r+1][c-1] 
     *                     and  course[r][c-1]==' '  and course[r+1][c-1]==' ' 
     */
    public boolean canMoveLeft(int r, int c)  {
        return 0<=r && r<=8 && 1<=c && c<=11
                && !hasRobot[r][c-1] && !hasRobot[r+1][c-1]
                && course[r][c-1]==' ' && course[r+1][c-1]==' ';
    }
    
    /** pre:    isAvailable(r, c)  and  robo.getParent()==null
     *  post:   not hasRobot[oldR][oldC]  and  not hasRobot[oldR][oldC+1]
     *          and  not hasRobot[oldR+1][oldC]  and  not hasRobot[oldR+1][oldC+1]
     *          and hasRobot[r][c]  and  hasRobot[r][c+1]
     *          and hasRobot[r+1][c]  and  hasRobot[r+1][c+1] 
     */
    public void moveRobotFromTo(int oldR, int oldC, int r, int c)  {
        hasRobot[oldR][oldC] = false;
        hasRobot[oldR][oldC+1] = false;
        hasRobot[oldR+1][oldC] = false;
        hasRobot[oldR+1][oldC+1] = false;
        hasRobot[r][c] = true;
        hasRobot[r][c+1] = true;
        hasRobot[r+1][c] = true;
        hasRobot[r+1][c+1] = true;
    }
        
}