迷路を解くためのバックトラッキングアルゴリズムを実装しようとしている部屋検索アルゴリズムを誰かが手伝ってくれるかどうかを探しています。すでに訪れた部屋を覚えておかなければならない場所で立ち往生しています。
迷路は部屋で構成されており、各部屋には北、東、南、西の4つの側面があります。各部屋は、希望する側にドアを作成することで次の部屋にリンクされます。つまり、room1.createNorth(roomName) 北に新しい部屋が作成され、新しい部屋には、私の部屋のクラスでわかるように、最初の部屋にリンクする南のドアがあります。
これが私の刻んだ部屋のクラスで、迷路の中の各部屋を表しています。北側を扱う方法と同じ南、西、東の方向を削除しました。
public class Room {
private String name;
private Room north;
private Room east;
private Room west;
private Room south;
private boolean isExit = false;
private Maze maze;
/**
* @return name room
*/
public String getName() {
return this.name;
}
/**
* Sets room name
*
* @param name
*/
public void setName(String name) {
this.name = name;
}
/**
* Gets northern room if any
*
* @return pointer to northern room if any, otherwise <code>null</code>
*/
public Room getNorth() {
return this.north;
}
/**
* Sets the door to the next room to the north in that room and in the other
* room sets southern door as connecting back to that room
*
* @param otherRoom
*/
public void setNorth(Room otherRoom) {
this.north = otherRoom;
otherRoom.south = this;
}
/**
* creates a new room to the north and connects back to this room
*
* @param name
* of the room
* @return created room
*/
public Room createNorth(String name) {
Room otherRoom = null;
// create new room in that direction ONLY if there is no room yet
if (this.getNorth() == null) { // get northern direction, if it's null,
// then it's okay to create there
otherRoom = new Room(); // create!
this.setNorth(otherRoom); // set the door
otherRoom.setName(name); // set the name
} else { // there is a room in that direction, so don't create a new
// room and drop a warning
System.out.println("There is already a room in northern direction");
}
return otherRoom;
}
/**
* Asdf
*
* @return maze
*/
public Maze getMaze() {
return this.maze;
}
/**
* Set maze
*
* @param maze
*/
public void setMaze(Maze maze) {
this.maze = maze;
}
/**
* @param roomName path to this room must be found
*/
public void findPathTo(String roomName) {
Room soughtRoom = this.getMaze().getEntry();
while (!(soughtRoom.getName().equalsIgnoreCase(roomName))) {
// here should be also a method such as setRoomAsVisited()
if (this.getWest() != null) {
soughtRoom = this.getWest();
this.getMaze().getPaths().push(soughtRoom);
}
else if (this.getNorth() != null) {
soughtRoom = this.getNorth();
this.getMaze().getPaths().push(soughtRoom);
}
else if (this.getEast() != null) {
soughtRoom = this.getEast();
this.getMaze().getPaths().push(soughtRoom);
}
else if (this.getSouth() != null) {
soughtRoom = this.getSouth();
this.getMaze().getPaths().push(soughtRoom);
}
else {
if (this.getMaze().getPaths().isEmpty()) {
break; // no more path for backtracking, exit (no solution found)
}
// dead end, go back!
soughtRoom = this.getMaze().getPaths().pop();
}
System.out.println(this.getMaze().getPaths().toString());
}
}
@Override
public String toString() {
return "Room name is " + this.getName();
}
}
迷路は次のようになります：http：//i.stack.imgur.com/2KePs.jpgここで、Sは開始点です
私の迷路のクラス
public class Maze {
Room room;
/**
* helper collection path stack for findPathTo() method
*/
private Stack<Room> paths = new Stack<Room>();
/**
* @return path for exit
*/
public Stack<Room> getPaths() {
return this.paths;
}
/**
* Singleton method for first room in the maze which is entry room
*
* @return room if no room is created then creates new, otherwise returns
* already created room
*/
public Room getEntry() {
if (this.room == null) {
this.room = new Room();
return this.room;
}
return this.room;
}
}
これが私のメインクラスのパブリッククラスですMain{
public static void main(String[] args) {
Maze maze = new Maze();
maze.getEntry().setName("A4"); // set first room's name A4
// labyrinth creation
maze.getEntry().createEast("B4").createNorth("B3").createWest("A3");
maze.getEntry().getEast().getNorth().createNorth("B2").createWest("A2")
.createNorth("A1");
maze.getEntry().getEast().getNorth().getNorth().createNorth("B1");
maze.getEntry().getEast().getNorth().getNorth().createEast("C2")
.createNorth("C1").createEast("D1");
maze.getEntry().getEast().createEast("C4").createEast("D4");
maze.getEntry().getEast().getEast().createNorth("C3").createEast("D3")
.createNorth("D2").setExit(true);
System.out.println("=====Test findPathTo method======");
maze.getEntry().setMaze(maze); // set maze instance to our entrance room
maze.getEntry().findPathTo("B4");
System.out.println("=====End of testing findPathTo method======");
}
}
問題はfindPathTo(roomName)、部屋へのルートを見つける私の方法にあります。部屋D4に入ると、アルゴリズムは「A4」から「B4」の部屋に東に1回だけ移動し、そこで無限にループし、スタックは部屋「B4」だけで大きくなります。たとえば、隣の部屋「B3」や「C4」に進んでみませんか？
編集：ここに作業コードがあります
public void findPathTo(String roomName) {
Room soughtRoom = this.getMaze().getEntry();
while (!(soughtRoom.getName().equalsIgnoreCase(roomName))) {
if (soughtRoom.getWest() != null && soughtRoom.getWest().isVisited != true) {
this.getMaze().getPaths().push(soughtRoom);
soughtRoom = soughtRoom.getWest();
soughtRoom.isVisited = true;
}
else if (soughtRoom.getNorth() != null && soughtRoom.getNorth().isVisited != true) {
this.getMaze().getPaths().push(soughtRoom);
soughtRoom = soughtRoom.getNorth();
soughtRoom.isVisited = true;
}
else if (soughtRoom.getEast() != null && soughtRoom.getEast().isVisited != true) {
this.getMaze().getPaths().push(soughtRoom);
soughtRoom = soughtRoom.getEast();
soughtRoom.isVisited = true;
}
else if (soughtRoom.getSouth() != null && soughtRoom.getSouth().isVisited != true) {
this.getMaze().getPaths().push(soughtRoom);
soughtRoom = soughtRoom.getSouth();
soughtRoom.isVisited = true;
}
else {
if (this.getMaze().getPaths().isEmpty()) {
System.out.println("No solutions found :(");
break; // no more path for backtracking, exit (no solution found)
}
// dead end, go back!
soughtRoom = this.getMaze().getPaths().pop();
}
System.out.println("Path rooms: " + this.getMaze().getPaths().toString());
}
}