8皇后Java递归

我正在为AP计算机科学课程的期末考试进行练习。无论如何，我刚刚学习了递归，我需要帮助将8皇后问题的几个方法简化为一个

我需要将第一行第八行方法合并为一个方法本身。该程序可以运行并打印所有92个解决方案，但它只需要简化

public class NonAttacking
{
    private static int [][] board = new int[8][8];

    private static int count = 0;

    public void rowOne(int y)
    {
        int x = 0;

        if(onBoard(x, y) != -1)     
        {
            if(validMove(x, y) == 0) //if the move is valid (0) then it puts a 1 at those coordinates and moves on to the next method (RowTwo)
            {
                board[x][y] = 1;
                rowTwo(0);
            }

            board[x][y] = 0;
            rowOne(y + 1);
        }
    }

    public void rowTwo(int col)
    {
        int x = 1;
        if(onBoard(x, col) != -1)       
        {
            if(validMove(x, col) == 0)
            {
                board[x][col] = 1;
                rowThree(0);
            }

            board[x][col] = 0;
            rowTwo(col + 1);

        }
    }

    public void rowThree(int col)
    {
        int x = 2;
        if(onBoard(x, col) != -1)       
        {
            if(validMove(x, col) == 0)
            {
                board[x][col] = 1;
                rowFour(0);
            }

            board[x][col] = 0;
            rowThree(col + 1);
        }
    }

    public void rowFour(int col) 
    {
        int x = 3;      
        if(onBoard(x, col) != -1)       
        {
            if(validMove(x, col) == 0)
            {
                board[x][col] = 1;
                rowFive(0);
            }

            board[x][col] = 0;
            rowFour(col + 1);
        }
    }

    public void rowFive(int col)
    {
        int x = 4;  
        if(onBoard(x, col) != -1)       
        {
            if(validMove(x, col) == 0)
            {
                board[x][col] = 1;
                rowSix(0);
            }
            board[x][col] = 0;
            rowFive(col + 1);
        }
    }

    public void rowSix(int col)
    {
        int row = 5;



        if(onBoard(row, col) != -1)     
        {
            if(validMove(row, col) == 0)
            {
                board[row][col] = 1;
                rowSeven(0);
            }

            board[row][col] = 0;
            rowSix(col + 1);
        }
    }

    public void rowSeven(int col)
    {
        int row = 6;    
        if(onBoard(row, col) != -1)     
        {
            if(validMove(row, col) == 0)
            {
                board[row][col] = 1;
                rowEight(0);
            }

            board[row][col] = 0;
            rowSeven(col + 1);
        }
    }

    public void rowEight(int col)
    {       
        int row = 7;    
        if(onBoard(row, col) != -1)     
        {
            if(validMove(row, col) == 0)
            {
                board[row][col] = 1;
                count++;

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

            board[row][col] = 0;
            rowEight(col + 1);
        }
    }


    public static int validMove(int row, int col)
    {
        for (int i = 0; i < 8; i++)
        {
            if(onBoard(row, i) == 1) //checks side to side
            {
                return -1;
            }
            if(onBoard(i, col) == 1) //checks up and down
            {
                return -1;
            }

        }

        //Check Diagonally
        for(int i = 0; i < 8; i++)
        {
            if(onBoard(row - i, col - i) == 1) //checks up and left
            {
                return -1;
            }

            if(onBoard(row - i, col + i) == 1) //checks up and right
            {
                return -1;
            }
            if(onBoard(row + i, col - i) == 1) //checks down and left
            {
                return -1;
            }
            if(onBoard(row + i, col + i) == 1) //checks down and right
            {
                return -1;
            }
        }


        return 0; //if it works
    }

    public static int onBoard(int row, int col)
    {
        if(row < 0 || col < 0 || row > 7 || col > 7) //checks if it is valid on the board
        {
            return -1;
        }


        return board[row][col]; //returns what the value is at the valid point
    }

    public String toString()
    {
        System.out.println(print());
        String ans = "Solution: ";
        ans += count;

        return ans;
    }

    public static String print()
    {
        String sol = "Solution: " + count;
        String result = "\n";
        for (int row = 0; row < board.length; row++)
        {
            for(int column = 0; column < board[row].length; column++)
            {
                result += board[row][column] + "\t";
            }
            result += "\n";
        }
        return result;

    }
}

---

`

如果您只想用一个方法替换这8个方法，那么应该根据需要执行以下操作，使用rowN（0，0）开始

public void rowN(int n, int y)
{
    if(onBoard(n, y) != -1)     
    {
        if(validMove(n, y) == 0) //if the move is valid (0) then it puts a 1 at those coordinates and moves on to the next method (RowTwo)
        {
            board[n][y] = 1;
            if(n<7) {
                rowN(n+1, 0);
            }
            else {
                count++;
                System.out.println(toString());
            }
        }

        board[n][y] = 0;
        rowN(n, y + 1);
    }
}

public void rowN（整数n，整数y）
{
如果（车载（n，y）！=-1）
{
如果（validMove（n，y）==0）//如果移动是有效的（0），那么它在这些坐标处放置一个1，并移动到下一个方法（第二行）
{
董事会[n][y]=1；
如果（nRowne方法仍然在底部被调用，那是怎么回事？我只是给rowN起个名字吗？任何你调用
Rowne
的地方，你调用
rowN
并使用
n
参数1。我确实将代码行
Rowne（y+1）；
重命名为
rowN（x，（y+1））
它只产生了这样的输出：
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
我的错我已经编辑了答案，你现在应该需要从rowN（0，0，0）开始相反。希望这能解决这个问题。在这个答案中，你混合使用了
x
和
n
，但只要你把它们都改成同一个变量，这似乎是可行的。
public void rowN(int n, int y)
{
    if(onBoard(n, y) != -1)     
    {
        if(validMove(n, y) == 0) //if the move is valid (0) then it puts a 1 at those coordinates and moves on to the next method (RowTwo)
        {
            board[n][y] = 1;
            if(n<7) {
                rowN(n+1, 0);
            }
            else {
                count++;
                System.out.println(toString());
            }
        }

        board[n][y] = 0;
        rowN(n, y + 1);
    }
}