java-深度优先遍历的迷宫和广度优先遍历的迷宫
1.深度优先遍历的迷宫
输入一个迷宫：
0 0 1 1 0
1 0 0 0 0
0 1 0 0 0
1 0 0 1 1
0 0 0 0 0
深度优先遍历，分别从四个方向找可走路径，先右，再下，再左，再上.缺点是，找到的路径非最短路径。
/**
* 描述:实现迷宫路径搜索需要的链式栈结构
*
* @Author shilei
* @Date 2019/5/18
*/
public class Stack<T> {
// top指向头节点，头节点的后面就是栈顶节点
private Entry<T> top;
public Stack(){
this.top = new Entry<>(null, null);
}
/**
* 入栈操作
* @param val
*/
public void push(T val){
Entry<T> node = new Entry<>(val, this.top.next);
this.top.next = node;
}
/**
* 出栈操作
* @return
*/
public T pop(){
T val = null;
if(this.top.next != null){
val = this.top.next.data;
this.top.next = this.top.next.next;
}
return val;
}
/**
* 查看栈顶元素
* @return
*/
public T peek(){
T val = null;
if(this.top.next != null){
val = this.top.next.data;
}
return val;
}
/**
* 判断栈空
* @return
*/
public boolean isEmpty(){
return this.top.next == null;
}
/**
* 节点类型定义
* @param
*/
static class Entry<T>{
T data;
Entry<T> next;
public Entry(T data, Entry<T> next) {
this.data = data;
this.next = next;
}
}
}
/**
* 描述: 把项目中所有出现的常量在这里统一定义
*
* @Author shilei
* @Date 2019/5/18
*/
public interface Constant {
// 右方向
int RIGHT = 0;
// 下方向
int DOWN = 1;
// 左方向
int LEFT = 2;
// 上方向
int UP = 3;
}
/**
* 描述: 迷宫的类型定义
*
* @Author shilei
* @Date 2019/5/18
*/
public class Maze {
// 迷宫所有的路径存储在二维数组当中
private MazeNode[][] maze;
// 存储迷宫路径节点的栈
private Stack<MazeNode> stack;
// 迷宫的行数
private int row;
// 迷宫的列数
private int col;
/**
* 迷宫初始化
* @param row
* @param col
*/
public Maze(int row, int col) {
this.row = row;
this.col = col;
this.maze = new MazeNode[row][col];
this.stack = new Stack<>();
}
/**
* 初始化指定位置的迷宫节点
* @param data
* @param i
* @param j
*/
public void initMazeNode(int data, int i, int j) {
this.maze[i][j] = new MazeNode(data, i, j);
}
/**
* 修改迷宫所有节点四个方向的行走状态信息
*/
public void initMazeNodePathState() {
for (int i = 0; i < row; i++) {
for (int j = 0; j < col; j++) {
if(j<col-1 && this.maze[i][j+1].val == 0){
this.maze[i][j].state[Constant.RIGHT] = true;
}
if(i<row-1 && this.maze[i+1][j].val == 0){
this.maze[i][j].state[Constant.DOWN] = true;
}
if(j>0 && this.maze[i][j-1].val == 0){
this.maze[i][j].state[Constant.LEFT] = true;
}
if(i>0 && this.maze[i-1][j].val == 0){
this.maze[i][j].state[Constant.UP] = true;
}
}
}
}
/**
* 寻找迷宫路径
*/
public void findMazePath() {
if(maze[0][0].val == 1){
return;
}
stack.push(maze[0][0]);
while(!stack.isEmpty()){
MazeNode top = stack.peek();
int x = top.x;
int y = top.y;
if(x == row-1 && y == col-1){
return;
}
// 往右方向走
if(maze[x][y].state[Constant.RIGHT]){
maze[x][y].state[Constant.RIGHT] = false;
maze[x][y+1].state[Constant.LEFT] = false;
stack.push(maze[x][y+1]);
continue;
}
// 往下方向走
if(maze[x][y].state[Constant.DOWN]){
maze[x][y].state[Constant.DOWN] = false;
maze[x+1][y].state[Constant.UP] = false;
stack.push(maze[x+1][y]);
continue;
}
// 往左方向走
if(maze[x][y].state[Constant.LEFT]){
maze[x][y].state[Constant.LEFT] = false;
maze[x][y-1].state[Constant.RIGHT] = false;
stack.push(maze[x][y-1]);
continue;
}
// 往上方向走
if(maze[x][y].state[Constant.UP]){
maze[x][y].state[Constant.UP] = false;
maze[x-1][y].state[Constant.DOWN] = false;
stack.push(maze[x-1][y]);
continue;
}
stack.pop();
}
}
/**
* 打印迷宫路径搜索的结果
*/
public void showMazePath() {
if(stack.isEmpty()){
System.out.println("迷宫不存在有效路径");
} else {
while(!stack.isEmpty()){
MazeNode top = stack.pop();
maze[top.x][top.y].val = '*';
}
for (int i = 0; i < row; i++) {
for (int j = 0; j < col; j++) {
if(maze[i][j].val == '*'){
System.out.print('*' + " ");
} else {
System.out.print(maze[i][j].val + " ");
}
}
System.out.println();
}
}
}
/**
* 描述: 定义迷宫节点类型
*/
private static class MazeNode {
// 节点的值
int val;
// 节点的x和y坐标
int x;
int y;
// 节点四个方向的行走状态，true表示可以走，false表示不能走
boolean[] state;
/**
* 迷宫路径初始化
* @param data
* @param i
* @param j
*/
public MazeNode(int data, int i, int j){
this.state = new boolean[4];
this.val = data;
this.x = i;
this.y = j;
}
}
}
/**
* 描述:
*
* @Author shilei
* @Date 2019/5/18
*/
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
System.out.print("请输入迷宫的行列数:");
int row, col, data;
row = in.nextInt();
col = in.nextInt();
Maze maze = new Maze(row, col);
System.out.println("请输入迷宫路径");
for (int i = 0; i < row; i++) {
for (int j = 0; j < col; j++) {
data = in.nextInt();
maze.initMazeNode(data, i, j);
}
}
// 修改迷宫所有节点四个方向的行走状态信息
maze.initMazeNodePathState();
// 寻找迷宫路径
maze.findMazePath();
// 打印迷宫路径搜索的结果
maze.showMazePath();
}
}
2.广度优先遍历的迷宫
层层遍历，可以直接找到出迷宫的最短路径：
/**
* 链式队列
* front：指向的是链表的头节点
* rear: 永远指向的是末尾节点
* @param
*/
public class LinkQueue<T>{
// 指向头节点(队头)
private Entry<T> front;
// 指向尾节点(队尾)
private Entry<T> rear;
// 记录队列节点的个数
private int count;
/**
* 初始化，front和rear都指向头节点
*/
public LinkQueue(){
this.front = this.rear = new Entry<>(null, null);
}
/**
* 入队操作
* @param val
*/
public void offer(T val){
Entry<T> node = new Entry<>(val, null);
this.rear.next = node;
this.rear = node;
this.count++;
}
/**
* 出队操作
* @return
*/
public T poll(){
T val = null;
if(this.front.next != null){
val = this.front.next.data;
this.front.next = this.front.next.next;
// 删除队列最后一个元素，要把rear指向front，队列才能判空
if(this.front.next == null){
this.rear = this.front;
}
this.count--;
}
return val;
}
public T peek(){
T val = null;
if(this.front.next != null){
val = this.front.next.data;
}
return val;
}
/**
* 判断队列空
* @return
*/
public boolean isEmpty(){
return this.front == this.rear;
}
/**
* 返回队列元素的个数
* @return
*/
public int size(){
return this.count;
}
/**
* 节点类型定义
* @param
*/
static class Entry<T>{
T data;
Entry<T> next;
public Entry(T data, Entry<T> next) {
this.data = data;
this.next = next;
}
}
}
/**
* 描述: 把项目中所有出现的常量在这里统一定义
*
* @Author shilei
* @Date 2019/5/18
*/
public interface Constant {
// 右方向
int RIGHT = 0;
// 下方向
int DOWN = 1;
// 左方向
int LEFT = 2;
// 上方向
int UP = 3;
}
/**
* 描述: 迷宫的类型定义
*
* @Author shilei
* @Date 2019/5/18
*/
public class Maze {
// 迷宫所有的路径存储在二维数组当中
private MazeNode[][] maze;
// 存储迷宫路径节点的队列结构，采用层层扩张的方式，寻找迷宫最优的路径信息
private LinkQueue<MazeNode> queue;
// 迷宫的行数
private int row;
// 迷宫的列数
private int col;
// 记录迷宫路径节点的行走信息
private MazeNode[] pathrecord;
/**
* 迷宫初始化
* @param row
* @param col
*/
public Maze(int row, int col) {
this.row = row;
this.col = col;
this.maze = new MazeNode[row][col];
this.queue = new LinkQueue<>();
this.pathrecord = new MazeNode[row*col];
}
/**
* 初始化指定位置的迷宫节点
* @param data
* @param i
* @param j
*/
public void initMazeNode(int data, int i, int j) {
this.maze[i][j] = new MazeNode(data, i, j);
}
/**
* 修改迷宫所有节点四个方向的行走状态信息
*/
public void initMazeNodePathState() {
for (int i = 0; i < row; i++) {
for (int j = 0; j < col; j++) {
//右
if(j<col-1 && this.maze[i][j+1].val == 0){
this.maze[i][j].state[Constant.RIGHT] = true;
}
//下
if(i<row-1 && this.maze[i+1][j].val == 0){
this.maze[i][j].state[Constant.DOWN] = true;
}
//左
if(j>0 && this.maze[i][j-1].val == 0){
this.maze[i][j].state[Constant.LEFT] = true;
}
//上
if(i>0 && this.maze[i-1][j].val == 0){
this.maze[i][j].state[Constant.UP] = true;
}
}
}
}
/**
* 寻找迷宫路径
*/
public void findMazePath() {
if(maze[0][0].val == 1){
return;
}
queue.offer(maze[0][0]);
while(!queue.isEmpty()){
MazeNode top = queue.peek();
int x = top.x;
int y = top.y;
if(x == row-1 && y == col-1){
return;
}
// 往右方向走
if(maze[x][y].state[Constant.RIGHT]){
maze[x][y].state[Constant.RIGHT] = false;
maze[x][y+1].state[Constant.LEFT] = false;
queue.offer(maze[x][y+1]);
pathrecord[x*col+y+1] = maze[x][y];
}
// 往下方向走
if(maze[x][y].state[Constant.DOWN]){
maze[x][y].state[Constant.DOWN] = false;
maze[x+1][y].state[Constant.UP] = false;
queue.offer(maze[x+1][y]);
pathrecord[(x+1)*col+y] = maze[x][y];
}
// 往左方向走
if(maze[x][y].state[Constant.LEFT]){
maze[x][y].state[Constant.LEFT] = false;
maze[x][y-1].state[Constant.RIGHT] = false;
queue.offer(maze[x][y-1]);
pathrecord[x*col+y-1] = maze[x][y];
}
// 往上方向走
if(maze[x][y].state[Constant.UP]){
maze[x][y].state[Constant.UP] = false;
maze[x-1][y].state[Constant.DOWN] = false;
queue.offer(maze[x-1][y]);
pathrecord[(x-1)*col+y] = maze[x][y];
}
queue.poll();
}
}
/**
* 打印迷宫路径搜索的结果
*/
public void showMazePath() {
if(pathrecord[row*col-1] == null){
System.out.println("迷宫不存在有效路径");
} else {
int x = row-1;
int y = col-1;
for(;;){
maze[x][y].val = '*';
MazeNode node = pathrecord[x*col+y];
if(node == null){
break;
}
x = node.x;
y = node.y;
}
for (int i = 0; i < row; i++) {
for (int j = 0; j < col; j++) {
if(maze[i][j].val == '*'){
System.out.print('*' + " ");
} else {
System.out.print(maze[i][j].val + " ");
}
}
System.out.println();
}
}
}
/**
* 描述: 定义迷宫节点类型
*/
private static class MazeNode {
// 节点的值
int val;
// 节点的x和y坐标
int x;
int y;
// 节点四个方向的行走状态，true表示可以走，false表示不能走
boolean[] state;
/**
* 迷宫路径初始化
* @param data
* @param i
* @param j
*/
public MazeNode(int data, int i, int j){
this.state = new boolean[4];
this.val = data;
this.x = i;
this.y = j;
}
}
}
/**
* 描述:
*
* @Author shilei
* @Date 2019/5/18
*/
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
System.out.print("请输入迷宫的行列数:");
int row, col, data;
row = in.nextInt();
col = in.nextInt();
Maze maze = new Maze(row, col);
System.out.println("请输入迷宫路径");
for (int i = 0; i < row; i++) {
for (int j = 0; j < col; j++) {
data = in.nextInt();
maze.initMazeNode(data, i, j);
}
}
// 修改迷宫所有节点四个方向的行走状态信息
maze.initMazeNodePathState();
// 寻找迷宫路径
maze.findMazePath();
// 打印迷宫路径搜索的结果
maze.showMazePath();
}
}