Java分别利用深度优先和广度优先求解迷宫路径
作者：天人合一peng
这篇文章主要为大家详细介绍了Java如何利用深度优先的非递归遍历方法和广度优先的遍历方法实现求解迷宫路径，文中的示例代码讲解详细，需要的可以参考一下
深度优先
实现效果
示例代码
import java.awt.*;
import javax.swing.*;
public class AlgoFrame extends JFrame{
private int canvasWidth;
private int canvasHeight;
public AlgoFrame(String title, int canvasWidth, int canvasHeight){
super(title);
this.canvasWidth = canvasWidth;
this.canvasHeight = canvasHeight;
AlgoCanvas canvas = new AlgoCanvas();
setContentPane(canvas);
pack();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setResizable(false);
setVisible(true);
}
public AlgoFrame(String title){
this(title, 1024, 768);
}
public int getCanvasWidth(){return canvasWidth;}
public int getCanvasHeight(){return canvasHeight;}
// data
private MazeData data;
public void render(MazeData data){
this.data = data;
repaint();
}
private class AlgoCanvas extends JPanel{
public AlgoCanvas(){
// 双缓存
super(true);
}
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D)g;
// 抗锯齿
// RenderingHints hints = new RenderingHints(
// RenderingHints.KEY_ANTIALIASING,
// RenderingHints.VALUE_ANTIALIAS_ON);
// hints.put(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
// g2d.addRenderingHints(hints);
// 具体绘制
int w = canvasWidth/data.M();
int h = canvasHeight/data.N();
for(int i = 0 ; i < data.N() ; i ++ )
{
for(int j = 0 ; j < data.M() ; j ++){
if (data.getMaze(i, j) == MazeData.WALL)
AlgoVisHelper.setColor(g2d, AlgoVisHelper.LightBlue);
else
AlgoVisHelper.setColor(g2d, AlgoVisHelper.White);
if(data.path[i][j])
AlgoVisHelper.setColor(g2d, AlgoVisHelper.Orange);
if(data.result[i][j])
AlgoVisHelper.setColor(g2d, AlgoVisHelper.Red);
AlgoVisHelper.fillRectangle(g2d, j * w, i * h, w, h);
}
}
}
@Override
public Dimension getPreferredSize(){
return new Dimension(canvasWidth, canvasHeight);
}
}
}
import java.awt.*;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Rectangle2D;
import java.lang.InterruptedException;
public class AlgoVisHelper {
private AlgoVisHelper(){}
public static final Color Red = new Color(0xF44336);
public static final Color Pink = new Color(0xE91E63);
public static final Color Purple = new Color(0x9C27B0);
public static final Color DeepPurple = new Color(0x673AB7);
public static final Color Indigo = new Color(0x3F51B5);
public static final Color Blue = new Color(0x2196F3);
public static final Color LightBlue = new Color(0x03A9F4);
public static final Color Cyan = new Color(0x00BCD4);
public static final Color Teal = new Color(0x009688);
public static final Color Green = new Color(0x4CAF50);
public static final Color LightGreen = new Color(0x8BC34A);
public static final Color Lime = new Color(0xCDDC39);
public static final Color Yellow = new Color(0xFFEB3B);
public static final Color Amber = new Color(0xFFC107);
public static final Color Orange = new Color(0xFF9800);
public static final Color DeepOrange = new Color(0xFF5722);
public static final Color Brown = new Color(0x795548);
public static final Color Grey = new Color(0x9E9E9E);
public static final Color BlueGrey = new Color(0x607D8B);
public static final Color Black = new Color(0x000000);
public static final Color White = new Color(0xFFFFFF);
public static void strokeCircle(Graphics2D g, int x, int y, int r){
Ellipse2D circle = new Ellipse2D.Double(x-r, y-r, 2*r, 2*r);
g.draw(circle);
}
public static void fillCircle(Graphics2D g, int x, int y, int r){
Ellipse2D circle = new Ellipse2D.Double(x-r, y-r, 2*r, 2*r);
g.fill(circle);
}
public static void strokeRectangle(Graphics2D g, int x, int y, int w, int h){
Rectangle2D rectangle = new Rectangle2D.Double(x, y, w, h);
g.draw(rectangle);
}
public static void fillRectangle(Graphics2D g, int x, int y, int w, int h){
Rectangle2D rectangle = new Rectangle2D.Double(x, y, w, h);
g.fill(rectangle);
}
public static void setColor(Graphics2D g, Color color){
g.setColor(color);
}
public static void setStrokeWidth(Graphics2D g, int w){
int strokeWidth = w;
g.setStroke(new BasicStroke(strokeWidth, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND));
}
public static void pause(int t) {
try {
Thread.sleep(t);
// System.out.println("Dely");
}
catch (InterruptedException e) {
System.out.println("Error sleeping");
}
}
}
import java.awt.*;
import java.util.Stack;
public class AlgoVisualizer {
private static int DELAY = 10;
private static int blockSide = 8;
private MazeData data;
private AlgoFrame frame;
private static final int d[][] = {{-1,0}, {0, 1}, {1, 0}, {0, -1}}; //左下右上
public AlgoVisualizer(String mazeFile){
// 初始化数据
data = new MazeData(mazeFile);
int sceneHeight = data.N() * blockSide;
int sceneWidth = data.M() * blockSide;
// 初始化视图
EventQueue.invokeLater(() -> {
frame = new AlgoFrame("Maze Solver Visualization", sceneWidth, sceneHeight);
new Thread(() -> {
run();
}).start();
});
}
public void run(){
setData(-1, -1, false);
Stack<Position> stack = new Stack<Position>();
Position entrance = new Position(data.getEntranceX(), data.getEntranceY());
stack.push(entrance);
data.visited[entrance.getX()][entrance.getY()] = true;
boolean isSolved = false;
while (!stack.empty()) {
Position curPos = stack.pop();
setData(curPos.getX(), curPos.getY(), true);
if (curPos.getX() == data.getExitX() && curPos.getY() == data.getExitY()) {
isSolved = true;
findPath(curPos); //find the path from the final position
break;
}
for (int i = 0; i < 4; i++) {
int newX = curPos.getX() + d[i][0];
int newY = curPos.getY() + d[i][1];
if (data.inArea(newX, newY) && !data.visited[newX][newY] &&
data.getMaze(newX, newY) == MazeData.ROAD) {
stack.push(new Position(newX, newY, curPos));
data.visited[newX][newY] = true;
}
}
}
if (!isSolved) {
System.out.println("the maze has no solution");
}
setData(-1, -1, false);
}
public void findPath(Position des) {
Position cur = des;
while (cur != null) {
data.result[cur.getX()][cur.getY()] = true;
cur = cur.getPrev();
}
}
private void setData(int x, int y, boolean isPath){
if (data.inArea(x, y)) {
data.path[x][y] = isPath;
}
frame.render(data);
AlgoVisHelper.pause(DELAY);
}
public static void main(String[] args) {
String mazeFile = "maze_101_101.txt";
AlgoVisualizer vis = new AlgoVisualizer(mazeFile);
}
}
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Scanner;
public class MazeData {
public static final char ROAD = ' ';
public static final char WALL = '#';
private int N, M;
private char[][] maze;
private int entranceX, entranceY;
private int exitX, exitY;
public boolean[][] visited;
public boolean[][] path;
public boolean[][] result;
public MazeData(String filename){
if(filename == null)
throw new IllegalArgumentException("Filename can not be null!");
Scanner scanner = null;
try{
File file = new File(filename);
if(!file.exists())
throw new IllegalArgumentException("File " + filename + " doesn't exist");
FileInputStream fis = new FileInputStream(file);
scanner = new Scanner(new BufferedInputStream(fis), "UTF-8");
// 读取第一行
String nmline = scanner.nextLine();
String[] nm = nmline.trim().split("\\s+");
//System.out.print(nm[0] + ' ' + nm[1]);
N = Integer.parseInt(nm[0]);
// System.out.println("N = " + N);
M = Integer.parseInt(nm[1]);
// System.out.println("M = " + M);
// 读取后续的N行
maze = new char[N][M];
visited = new boolean[N][M];
path = new boolean[N][M];
result = new boolean[N][M];
for(int i = 0 ; i < N ; i ++){
String line = scanner.nextLine();
// 每行保证有M个字符
if(line.length() != M)
throw new IllegalArgumentException("Maze file " + filename + " is invalid");
for(int j = 0 ; j < M ; j ++)
{
maze[i][j] = line.charAt(j);
visited[i][j] = false;
path[i][j] = false;
result[i][j] = false;
}
}
}
catch(IOException e){
e.printStackTrace();
}
finally {
if(scanner != null)
scanner.close();
}
entranceX = 1;
entranceY = 0;
exitX = N - 2 ;
exitY = M - 1;
}
public int N(){ return N; }
public int M(){ return M; }
public int getEntranceX() {return entranceX;}
public int getEntranceY() {return entranceY;}
public int getExitX() { return exitX;}
public int getExitY() { return exitY;}
public char getMaze(int i, int j){
if(!inArea(i,j))
throw new IllegalArgumentException("i or j is out of index in getMaze!");
return maze[i][j];
}
public boolean inArea(int x, int y){
return x >= 0 && x < N && y >= 0 && y < M;
}
public void print(){
System.out.println(N + " " + M);
for(int i = 0 ; i < N ; i ++){
for(int j = 0 ; j < M ; j ++)
System.out.print(maze[i][j]);
System.out.println();
}
return;
}
}
public class Position {
private int x, y;
private Position prev;
public Position(int x, int y, Position prev ) {
// TODO Auto-generated constructor stub
this.x = x;
this.y = y;
this.prev = prev;
}
public Position(int x, int y) {
// TODO Auto-generated constructor stub
this(x, y, null);
}
public int getX() { return x;}
public int getY() { return y;}
public Position getPrev() {return prev;}
}上面是深度优先的非递归遍历方法
下面是广度优先的遍历方法
广度优先
实现效果
示例代码
import java.awt.*;
import java.util.LinkedList;
import java.util.Stack;
public class AlgoVisualizer {
private static int DELAY = 10;
private static int blockSide = 8;
private MazeData data;
private AlgoFrame frame;
private static final int d[][] = {{-1,0}, {0, 1}, {1, 0}, {0, -1}}; //左下右上
public AlgoVisualizer(String mazeFile){
// 初始化数据
data = new MazeData(mazeFile);
int sceneHeight = data.N() * blockSide;
int sceneWidth = data.M() * blockSide;
// 初始化视图
EventQueue.invokeLater(() -> {
frame = new AlgoFrame("Maze Solver Visualization", sceneWidth, sceneHeight);
new Thread(() -> {
run();
}).start();
});
}
public void run(){
setData(-1, -1, false);
LinkedList<Position> queue = new LinkedList<Position>();
Position entrance = new Position(data.getEntranceX(), data.getEntranceY());
queue.addLast(entrance);
data.visited[entrance.getX()][entrance.getY()] = true;
boolean isSolved = false;
while ( queue.size() != 0) {
Position curPos = queue.pop();
setData(curPos.getX(), curPos.getY(), true);
if (curPos.getX() == data.getExitX() && curPos.getY() == data.getExitY()) {
isSolved = true;
findPath(curPos); //find the path from the final position
break;
}
for (int i = 0; i < 4; i++) {
int newX = curPos.getX() + d[i][0];
int newY = curPos.getY() + d[i][1];
if (data.inArea(newX, newY) && !data.visited[newX][newY] &&
data.getMaze(newX, newY) == MazeData.ROAD) {
queue.addLast(new Position(newX, newY, curPos));
data.visited[newX][newY] = true;
}
}
}
if (!isSolved) {
System.out.println("the maze has no solution");
}
setData(-1, -1, false);
}
public void findPath(Position des) {
Position cur = des;
while (cur != null) {
data.result[cur.getX()][cur.getY()] = true;
cur = cur.getPrev();
}
}
private void setData(int x, int y, boolean isPath){
if (data.inArea(x, y)) {
data.path[x][y] = isPath;
}
frame.render(data);
AlgoVisHelper.pause(DELAY);
}
public static void main(String[] args) {
String mazeFile = "maze_101_101.txt";
AlgoVisualizer vis = new AlgoVisualizer(mazeFile);
}
}知识点总结
q为抽象的队列
以上就是Java分别利用深度优先和广度优先求解迷宫路径的详细内容，更多关于Java求解迷宫路径的资料请关注脚本之家其它相关文章！