java - ArrayList添加不增加列表

Question

我正在尝试使用启发式搜索来解决 8 谜题问题。我使用 3*3 矩阵来表示可能性。代码并不完整，但是当我尝试将探索的元素添加到探索的集合(这是一个 ArrayList)时，它只更新探索的集合中的当前元素，而不是在末尾添加一个元素。当我尝试打印探索集中的所有元素时，始终只有一个元素(每次迭代都会更新)。我想知道我的代码有什么问题。谢谢你!!

public static void printexplored(ArrayList<int[][]> explored){
        //System.out.println("the size of the explored set is " + explored.size());
        System.out.println("the explored set is...");
        while(explored.isEmpty() == false){
            int[][] temp = explored.remove(0);
            for(int i = 0; i < 3; i++){
                for(int j = 0; j < 3; j++){
                    System.out.print(temp[i][j]);
                }
                System.out.println();
            }
            System.out.println();
        }
    } 


public static boolean heuristicSearch(int initialState[][]){
        Queue<int[][]> frontier = new LinkedList<int[][]>();
        frontier.add(initialState);
        ArrayList<int[][]> explored = new ArrayList<int[][]>();
        int f_score = 0;
        //int count = 0;

        while(frontier.isEmpty() == false){

            int[][] temporaryState = new int[3][3]; 

            temporaryState = frontier.remove();
            int indexX = blankIndexX(temporaryState);
            int indexY = blankIndexY(temporaryState);

            explored.add(temporaryState);

            printexplored(explored);

Answer 1

您的代码不完整，但立即引人注目的一件事是您同时向探索列表添加和删除元素。请参阅下面的评论:

public static void printexplored(ArrayList<int[][]> explored){
        //System.out.println("the size of the explored set is " + explored.size());
        System.out.println("the explored set is...");
        while(explored.isEmpty() == false){

//---->YOU REMOVED THE ELEMENT WHICH WAS ADDED EARLIER HERE:

            int[][] temp = explored.remove(0);
            for(int i = 0; i < 3; i++){
                for(int j = 0; j < 3; j++){
                    System.out.print(temp[i][j]);
                }
                System.out.println();
            }
            System.out.println();
        }
    } 


public static boolean heuristicSearch(int initialState[][]){
        Queue<int[][]> frontier = new LinkedList<int[][]>();
        frontier.add(initialState);
        ArrayList<int[][]> explored = new ArrayList<int[][]>();
        int f_score = 0;
        //int count = 0;

        while(frontier.isEmpty() == false){

            int[][] temporaryState = new int[3][3]; 

            temporaryState = frontier.remove();
            int indexX = blankIndexX(temporaryState);
            int indexY = blankIndexY(temporaryState);

    //---->YOU ARE ADDING AN ELEMENT HERE BUT REMOVING IT LATER IN THE THE 
    //printexplored METHOD:

            explored.add(temporaryState);

            printexplored(explored);