我正在尝试通过A *搜索创建一个难题解决算法。一切都应该正确，但是当我尝试使用实现的新“ MoveUp MoveDown MoveLeft MoveRight”类之一时遇到了一个错误（声明的包“ rushhour”与预期的包不匹配）

下移

package rushhour;

import search.action;
import search.State;

public class MoveDown implements action{

    int carNum;
    int nPositions;

    public MoveDown(int carNum,int nPositions){
        this.carNum = carNum;
        this.nPositions = nPositions;
    }

    public int getcost() {
        return 1;
    }

    public String toString(){
        return "move down";
    }

}

然后我在其中使用的类如下

package rushhour;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import javax.lang.model.element.Element;

import search.action;
import search.State;


public class GameState implements search.State {

    boolean[][] occupiedPositions;
    List<Car> cars; // target car is always the first one    
    int nrRows;
    int nrCols;
...
...
...
public boolean isLegal(action action) {


        if(action instanceof MoveDown){

            Car car = cars.get(((MoveDown) action).carNum); 
            int nextPos = car.getRow() + car.getLength() + ((MoveDown) action).nPositions;