Question

我制作了一个包含整数值的2D数组，并想将其转换为字符串，但是我对能够放入//以获得所需输出的东西感到困惑。

public static void main(String[] args) {
    final int [][] test = { {1, 6, 11, 16, 21}, 
                            {2, 7, 12, 17, 22}, 
                            {3, 8, 13, 18, 23}, 
                            {4, 9, 14, 19, 24}, 
                            {5, 10, 15, 20, 25} };
    System.out.println(TwoDOneD.DownNUp(test));

public static String DownNUp(int [][] test) {
    String res = "";
    for (int r = 0; r < test[0].length; r++) {
         for (int c = 0; c < test.length; c++) {
            if (c % 2 == 1) {
                //something
            } else {
                res += test[c][r] + " ";
            }
        }
    }
    return res;
}

我试图获得的输出就是为什么我有（c％2 == 1）;在每一个奇数列中，它都应该下降，而在每个偶数列中，它都应该右退。

1 2 3 4 5 10 9 8 7 6 11 12 13 14 15 20 19 18 17 16 21 22 23 24 25

Answer 1

您需要根据c % 2 == 0

更改迭代方向

public static void main(String[] args) {

    final int [][] test = { {1, 6, 11, 16, 21}, 
            {2, 7, 12, 17, 22}, 
            {3, 8, 13, 18, 23}, 
            {4, 9, 14, 19, 24}, 
            {5, 10, 15, 20, 25} };
    System.out.println(downUp(test));
}

public static String downUp(int [][] test) {
    String res = "";
    for (int c = 0; c < test[0].length; c++) {

        if (c % 2 == 0) {
            for (int r = 0; r < test.length; r++) {
                res += test[r][c] + " ";
            }

        } else {

            for (int r = test.length -1 ; r >=0 ; r--) {
                res += test[r][c] + " ";
            }
        }
    }
    return res;
}

旁注：最好像这样使用StringBuilder来实现：

public static String downUp(int [][] test) {

    StringBuilder res = new StringBuilder();

    for (int c = 0; c < test[0].length; c++) {

        if (c % 2 == 0) {
            for (int r = 0; r < test.length; r++) {
                res.append(test[r][c]).append(" ");
            }

        } else {

            for (int r = test.length -1 ; r >=0 ; r--) {
                res.append(test[r][c]).append(" ");
            }
        }
    }
    return res.toString();
}

Answer 2

我认为这是您想要的：

public static String DownNUp(int[][] test) {
        String res = "";
        for (int r = 0; r < test[0].length; r++) {
            for (int c = 0; c < test.length; c++) {

                if (r % 2 != 0) {
                    res += test[test.length - 1 - c][r] + " ";
                } else {
                    res += test[c][r] + " ";
                }
            }
        }
        return res;
    }

将2D整数数组转换为String

2 个答案: