java - 2048 合并方法帮助

Question

我试图弄清楚如何使用右、上、下、左移位方法。我觉得我的解决方案应该很有效，如果我说错了或其他什么。

主要的

import java.util.Random;
import java.util.Scanner;
import java.util.*;
public class Runner
{
    int[][] board = new int[4][4];
    Scanner input = new Scanner(System.in);
    public void printWelcomeAndDirections()
    {
        //instructions
        System.out.println("press r to start or restart");
        System.out.println("press u to move up");
        System.out.println("press d to move down");
        System.out.println("press r to move right");
        System.out.println("press l to move left");
        System.out.println("slides multiples of the same number together to form an even bigger number. Do this till no more combinations are possible or the number 2048 is reached");
    }

    public void placeBlock()
    {
        Random rad = new Random();
        int a = rad.nextInt(4);
        int b = rad.nextInt(4);
        boolean tf = false;
        while(tf == false)
        {

            if(board[a][b] == 0)
            {
                board[a][b] = 2;
                tf = true;
            }
            a = rad.nextInt(4);
            b = rad.nextInt(4);
        }

    }

    public void printBoard()
    {
        int rows=4;
        int cols=4;
        int boxSize = 4;
        String rowdashes = "-----------------";
        for(int i = 0; i < board.length; i++)
        {
            System.out.println(rowdashes);
            System.out.print("|");
            for(int j = 0; j < board[i].length; j++)
            {
                String number = "";
                if(board[i][j] != 0)
                {
                    number = board[i][j] + "";
                }

                System.out.print("   " + number + "|");

            }
            System.out.println();
        }
        System.out.println(rowdashes);
    }

    public String getUserChoice()
    {
        String a = input.nextLine();
        return a;
    }

    public void processUserChoice()
    {
        if(getUserChoice().equals("u"))
        {
            slideUp();
        }
        else if(getUserChoice().equals("d"))
        {
            slideDown();
        }

        else if(getUserChoice().equals("l"))
        {
            slideLeft();
        }

        else if (getUserChoice().equals("r"))
        {
            slideRight();
        }
    }

    public boolean slideUp()
    {
        for(int i = 4; i >= 1; i--)
        {
            for(int j = 4; j > 0; j--)
            {
                if(board[i][j] == board[i-1][j])
                {
                    board[i][j] = board[i-1][j] * 2;
                    board[i-1][j] = 0;
                    return true;
                }
                else if(board[i][j] == 0)
                {
                    board[i][j] = board[i-1][j];
                    return true;
                }

            }

        }
        return false;
    }

    public boolean slideRight()
    {
        for(int i = 4; i >= 0; i--)
        {
            for(int j = 4; j >= 1; j--)
            {
                if(board[i][j] == board[i][j-1])
                {
                    board[i][j] = board[i][j-1] * 2;
                    board[i][j-1] = 0;
                    return true;
                }
                else if(board[i][j] == 0)
                {
                    board[i][j] = board[i][j-1];
                    return true;
                }

            }

        }
        return false;
    }

    public boolean slideLeft()
    {
        for(int i = 4; i >= 0; i++)
        {
            for(int j = 4; j >= 1; j++)
            {
                if(board[i][j] == board[i][j+1])
                {
                    board[i][j] = board[i][j+1] * 2;
                    board[i][j+1] = 0;
                    return true;
                }
                else if(board[i][j] == 0)
                {
                    board[i][j] = board[i][j+1];
                    return true;
                }

            }

        }
        return false;
    }

    public boolean slideDown()
    {
        return false;
    }

    public int gameover()
    {
        return 0;
    }
}

Test

public class test
{
    public static void main(String [] args)
    {
        Runner a = new Runner();
        a.printWelcomeAndDirections();
        a.printBoard();
        while(a.gameover() == 0)
        {
            a.placeBlock();
            a.printBoard();
            a.processUserChoice();
        }
    }
}

我期待董事会在任何所谓的方向上转移，但事实并非如此。

电路板打印并在 0 所在的位置添加 2。除此之外什么都不做。