基于Java的"迷宫问题"求解(带算法描述)

       这学期的算法课，老师要求期中做一个算法设计出来，我选择了迷宫。自己当时没有想出好的算法来，后来参考了网上一篇关于迷宫算法的论文，于是写出了这个迷宫求解程序。现在将程序分享出来，如有不妥之处，敬请大家指正。

package com.sailor.maze;

/****************************************************************************/
/**Author: Sailor                                                          */
/**Vision: Maze1.00                                                       */
/**Date: 2010-04-15                                                      */
/**E-Mail:zpsailor@yahoo.com.cn                                         */
/**QQ:251396377                                                        */
/**********************************************************************/
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.TimerTask;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;

// 迷宫
@SuppressWarnings("serial")
public class Maze extends JFrame implements ActionListener {

private JPanel panel;
private JPanel northPanel;
private JPanel centerPanel;
private MazeGrid grid[][];
private JButton restart;
private JButton dostart;
private int rows;// rows 和cols目前暂定只能是奇数
private int cols;
private List<String> willVisit;
private List<String> visited;
private LinkedList<String> comed;
private long startTime;
private long endTime;

public Maze() {
rows = 25;
cols = 25;
willVisit = new ArrayList<String>();
visited = new ArrayList<String>();
comed = new LinkedList<String>();
init();
this.setTitle("回溯法--走迷宫");
this.add(panel);
this.pack();
this.setVisible(true);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

public void init() {
panel = new JPanel();
northPanel = new JPanel();
centerPanel = new JPanel();
panel.setLayout(new BorderLayout());
restart = new JButton("重新生成迷宫");
dostart = new JButton("开始走迷宫");
grid = new MazeGrid[rows][cols];

centerPanel.setLayout(new GridLayout(rows, cols, 1, 1));
centerPanel.setBackground(new Color(0, 0, 0));
northPanel.add(restart);
northPanel.add(dostart);

dostart.addActionListener(this);
restart.addActionListener(this);
for (int i = 0; i < grid.length; i++)
for (int j = 0; j < grid[i].length; j++) {
if (j % 2 == 0 && i % 2 == 0)
grid[i][j] = new MazeGrid(true, 20, 20);
else
grid[i][j] = new MazeGrid(false, 20, 20);
}
grid[0][0].setVisited(true);
grid[0][0].setPersonCome(true);
grid[0][0].setStart(true);
visited.add("0#0");
grid[rows - 1][cols - 1].setEnd(true);
grid = createMap(grid, 0, 0);
for (int i = 0; i < grid.length; i++)
for (int j = 0; j < grid[i].length; j++) {
grid[i][j].repaint();
centerPanel.add(grid[i][j]);
}

panel.add(northPanel, BorderLayout.NORTH);
panel.add(centerPanel, BorderLayout.CENTER);
}

/**
* 生成迷宫
*
* @param mazeGrid
* @param x
* @param y
* @return
*/
public MazeGrid[][] createMap(MazeGrid mazeGrid[][], int x, int y) {
int visitX = 0;
int visitY = 0;
if (x - 2 >= 0) {
if (!mazeGrid[x - 2][y].isVisited()) {
willVisit.add((x - 2) + "#" + y);
}
}
if (x + 2 < cols) {
if (!mazeGrid[x + 2][y].isVisited()) {
willVisit.add((x + 2) + "#" + y);
}
}
if (y - 2 >= 0) {
if (!mazeGrid[x][y - 2].isVisited()) {
willVisit.add(x + "#" + (y - 2));
}
}
if (y + 2 < rows) {
if (!mazeGrid[x][y + 2].isVisited()) {
willVisit.add(x + "#" + (y + 2));
}
}
if (!willVisit.isEmpty()) {
int visit = (int) (Math.random() * willVisit.size());
String id = willVisit.get(visit);
visitX = Integer.parseInt(id.split("#")[0]);
visitY = Integer.parseInt(id.split("#")[1]);
mazeGrid[(visitX + x) / 2][(visitY + y) / 2].setMark(true);

mazeGrid[visitX][visitY].setVisited(true);
if (!visited.contains(id)) {// 将这个点加到已访问中去
visited.add(id);
}
willVisit.clear();
createMap(mazeGrid, visitX, visitY);
} else {
if (!visited.isEmpty()) {
String id = visited.remove(visited.size() - 1);// 取出最后一个元素
visitX = Integer.parseInt(id.split("#")[0]);
visitY = Integer.parseInt(id.split("#")[1]);
mazeGrid[visitX][visitY].setVisited(true);
createMap(mazeGrid, visitX, visitY);
}
}
return mazeGrid;
}

/**
* 走迷宫
*
* @param mazeGrid
* @param x
* @param y
*/
public String goMaze(MazeGrid mazeGrid[][], int x, int y) {
int comeX = 0;
int comeY = 0;
// left
if (x - 1 >= 0) {
if (mazeGrid[x - 1][y].isMark()) {
if (!comed.contains((x - 1) + "#" + y))
willVisit.add((x - 1) + "#" + y);
}
}
// right
if (x + 1 < cols) {
if (mazeGrid[x + 1][y].isMark()) {
if (!comed.contains((x + 1) + "#" + y))
willVisit.add((x + 1) + "#" + y);
}
}
// up
if (y - 1 >= 0) {
if (mazeGrid[x][y - 1].isMark()) {
if (!comed.contains(x + "#" + (y - 1)))
willVisit.add(x + "#" + (y - 1));
}
}
// down
if (y + 1 < rows) {
if (mazeGrid[x][y + 1].isMark()) {
if (!comed.contains(x + "#" + (y + 1)))
willVisit.add(x + "#" + (y + 1));
}
}
if (!willVisit.isEmpty()) {
int visit = (int) (Math.random() * willVisit.size());
String id = willVisit.get(visit);
comeX = Integer.parseInt(id.split("#")[0]);
comeY = Integer.parseInt(id.split("#")[1]);
mazeGrid[x][y].setPersonCome(false);
mazeGrid[comeX][comeY].setPersonCome(true);
mazeGrid[x][y].repaint();
mazeGrid[comeX][comeY].repaint();
willVisit.clear();
comed.add(x + "#" + y);
} else {
if (!comed.isEmpty()) {
String id = comed.removeLast();
comeX = Integer.parseInt(id.split("#")[0]);
comeY = Integer.parseInt(id.split("#")[1]);
mazeGrid[x][y].setPersonCome(false);
mazeGrid[comeX][comeY].setPersonCome(true);
mazeGrid[x][y].repaint();
mazeGrid[comeX][comeY].repaint();
comed.addFirst(x + "#" + y);
}
}
return comeX + "#" + comeY;
}

int comeX = 0;
int comeY = 0;

@Override
public void actionPerformed(ActionEvent e) {
if (e.getActionCommand().equals("重新生成迷宫")) {
refreshMap(grid);
} else if (e.getActionCommand().equals("开始走迷宫")) {
startTime = System.currentTimeMillis();
dostart.setVisible(false);
restart.setText("禁止刷新");
int delay = 1000;
int period = 500;// 循环间隔
java.util.Timer timer = new java.util.Timer();
timer.scheduleAtFixedRate(new TimerTask() {
public void run() {
if (grid[rows - 1][cols - 1].isPersonCome()) {
endTime = System.currentTimeMillis();
JOptionPane.showMessageDialog(null, "已经走出迷宫，耗时"
+ (endTime - startTime) / 1000 + "秒", "消息提示",
JOptionPane.ERROR_MESSAGE);
this.cancel();
restart.setText("重新生成迷宫");
} else {
String id = goMaze(grid, comeX, comeY);
comeX = Integer.parseInt(id.split("#")[0]);
comeY = Integer.parseInt(id.split("#")[1]);
}
}
}, delay, period);
}
}

/**
* 刷新地图
*/
public void refreshMap(MazeGrid mazeGrid[][]) {
comeX = 0;
comeY = 0;
willVisit.clear();
visited.clear();
comed.clear();
this.remove(panel);
init();
this.add(panel);
this.pack();
this.setVisible(true);
}

public static void main(String args[]) {
long start = System.currentTimeMillis();
new Maze();
long end = System.currentTimeMillis();
System.out.println("使用ArrayList生成迷宫耗时：" + (end - start) + "毫秒");
}
}

package com.sailor.maze;

import java.awt.Canvas;
import java.awt.Color;
import java.awt.Graphics;

@SuppressWarnings("serial")
public class MazeGrid extends Canvas {

private boolean mark;// 标记是否是通路，TRUE为通路，FALSE为不通
private boolean isVisited;// 标记是否是访问过的,这是在生成迷宫的时候判断的。
private boolean isPersonCome;// 标记是否已经走过
private boolean isStart;// 判断是否为入口
private boolean isEnd;// 判断是否为出口

public MazeGrid() {
this.setBackground(new Color(120, 0, 0));
this.setSize(25, 25);
}

public MazeGrid(boolean mark, int width, int height) {
this.mark = mark;
this.setSize(width, height);
if (mark == true) {
this.setBackground(new Color(255, 255, 255));
} else {
this.setBackground(new Color(120, 0, 0));
}
}

public boolean isMark() {
return mark;
}

public void setMark(boolean mark) {
this.mark = mark;
}

public void paint(Graphics g) {
if (this.mark) {
if (this.isStart || this.isEnd) {
this.setBackground(new Color(255,0,0));
} else
this.setBackground(new Color(255, 255, 255));
} else {
this.setBackground(new Color(120, 0, 0));
}
if (this.isPersonCome) {
g.setColor(Color.BLACK);
g.fillOval(2, 2, 15, 15);
}

}

public boolean isVisited() {
return isVisited;
}

public void setVisited(boolean isVisited) {
this.isVisited = isVisited;
}

public boolean isPersonCome() {
return isPersonCome;
}

public void setPersonCome(boolean isPersonCome) {
this.isPersonCome = isPersonCome;
}

public boolean isStart() {
return isStart;
}

public void setStart(boolean isStart) {
this.isStart = isStart;
}

public boolean isEnd() {
return isEnd;
}

public void setEnd(boolean isEnd) {
this.isEnd = isEnd;
}
}