Question

我正在尝试让我的应用程序获取一组随机数，并使用rnd（1..8）的所有可能组合。组合是索引数组（长度在2-99之间）。我已经模仿了一些测试代码来展示我到目前为止所拥有的内容，并且包含了我在底部寻找的结果。

为了成功做到这一点，我们想看看功能......

private static int[] updateArray(int[] array){
    for (int index = array.length - 1 ; index >= 0; index--){
        if (array[index] > 1){
            array[index]--;
            return array;
        } else if (array[index] == 1 && index != 0) {
            if (array[index - 1] != 1) {
                array[index - 1]--;
                array[index] = maxNum;
                return array;
            }
        }
        index--;
    }

    return array;
}

注意：我可能没有使用上面的正确算法。

以下是编译结果的完整代码......

public class Test {
    private static final int maxNum = 8;

    private static int[] updateArray(int[] array){
        for (int index = array.length - 1 ; index >= 0; index--){
            if (array[index] > 1){
                array[index]--;
                return array;
            } else if (array[index] == 1 && index != 0) {
                if (array[index - 1] != 1) {
                    array[index - 1]--;
                    array[index] = maxNum;
                    return array;
                }
            }
            index--;
        }

        return array;
    }

    private static boolean isArrayIndexesAllOnes(int[] array){
        for (int element: array){
            if (element != 1){
                return false;
            }
        }
        return true;
    }

    private static void printArrayCountdown(int[] array){
        boolean downToOne = false;

        while (!downToOne){
            array = updateArray(array);
            printArray(array);
            if (isArrayIndexesAllOnes(array)){
                downToOne = true;
            }
        }
    }

    private static void printArray(int[] array){
        for (int index = 0; index < array.length; index++){

            if (index == 0) {
                System.out.print("{" + array[index] + ",");
            } else if (index > 0 && index < array.length - 1){
                System.out.print(array[index] + ",");
            } else {
                System.out.println(array[index] + "}");
            }
        }
    }

    public static void main(String[] args) {
        int[] firstArray = {maxNum,maxNum};
        int[] secondArray = {maxNum,maxNum,maxNum};

        printArrayCountdown(firstArray);
        System.out.println();
        System.out.println();
        printArrayCountdown(secondArray);
    }
}

firstArray ...

的预期输出

{8,7}
{8,6}
{8,5}
{8,4}
{8,3}
{8,2}
{8,1}
{7,8}
{7,7}
{7,6}
{7,5}
{7,4}
{7,3}
{7,2}
{7,1}
{6,8}
{6,7}
{6,6}
{6,5}
{6,4}
{6,3}
{6,2}
{6,1}
{5,8}
{5,7}
{5,6}
{5,5}
{5,4}
{5,3}
{5,2}
{5,1}
{4,8}
{4,7}
{4,6}
{4,5}
{4,4}
{4,3}
{4,2}
{4,1}
{3,8}
{3,7}
{3,6}
{3,5}
{3,4}
{3,3}
{3,2}
{3,1}
{2,8}
{2,7}
{2,6}
{2,5}
{2,4}
{2,3}
{2,2}
{2,1}
{1,8}
{1,7}
{1,6}
{1,5}
{1,4}
{1,3}
{1,2}
{1,1}

成功！

但是如果有一个包含2个以上索引的数组（例如：secondArray），我会得到这个输出：

{8,8,7}
{8,8,6}
{8,8,5}
{8,8,4}
{8,8,3}
{8,8,2}
{8,8,1}
{8,7,8}
{8,7,7}
{8,7,6}
{8,7,5}
{8,7,4}
{8,7,3}
{8,7,2}
{8,7,1}
{8,6,8}
{8,6,7}
{8,6,6}
{8,6,5}
{8,6,4}
{8,6,3}
{8,6,2}
{8,6,1}
{8,5,8}
{8,5,7}
{8,5,6}
{8,5,5}
{8,5,4}
{8,5,3}
{8,5,2}
{8,5,1}
{8,4,8}
{8,4,7}
{8,4,6}
{8,4,5}
{8,4,4}
{8,4,3}
{8,4,2}
{8,4,1}
{8,3,8}
{8,3,7}
{8,3,6}
{8,3,5}
{8,3,4}
{8,3,3}
{8,3,2}
{8,3,1}
{8,2,8}
{8,2,7}
{8,2,6}
{8,2,5}
{8,2,4}
{8,2,3}
{8,2,2}
{8,2,1}
{8,1,8}
{8,1,7}
{8,1,6}
{8,1,5}
{8,1,4}
{8,1,3}
{8,1,2}
{8,1,1}
{7,1,1}
{6,1,1}
{5,1,1}
{4,1,1}
{3,1,1}
{2,1,1}
{1,1,1}

逻辑错误！

相反，这是预期输出 ...

{8,8,7}
{8,8,6}
{8,8,5}
{8,8,4}
{8,8,3}
{8,8,2}
{8,8,1}
{8,7,8}
{8,7,7}
{8,7,6}
{8,7,5}
{8,7,4}
{8,7,3}
{8,7,2}
{8,7,1}
{8,6,8}
{8,6,7}
{8,6,6}
{8,6,5}
{8,6,4}
{8,6,3}
{8,6,2}
{8,6,1}
{8,5,8}
{8,5,7}
{8,5,6}
{8,5,5}
{8,5,4}
{8,5,3}
{8,5,2}
{8,5,1}
{8,4,8}
{8,4,7}
{8,4,6}
{8,4,5}
{8,4,4}
{8,4,3}
{8,4,2}
{8,4,1}
{8,3,8}
{8,3,7}
{8,3,6}
{8,3,5}
{8,3,4}
{8,3,3}
{8,3,2}
{8,3,1}
{8,2,8}
{8,2,7}
{8,2,6}
{8,2,5}
{8,2,4}
{8,2,3}
{8,2,2}
{8,2,1}
{8,1,8}
{8,1,7}
{8,1,6}
{8,1,5}
{8,1,4}
{8,1,3}
{8,1,2}
{8,1,1}
{7,8,8}
{7,8,7}
{7,8,6}
{7,8,5}
{7,8,4}
{7,8,3}
{7,8,2}
{7,8,1}
{7,7,8}
{7,7,7}
{7,7,6}
{7,7,5}
{7,7,4}
{7,7,3}
{7,7,2}
{7,7,1}
{7,6,8}
{7,6,7}
{7,6,6}
{7,6,5}
{7,6,4}
{7,6,3}
{7,6,2}
{7,6,1}
{7,5,8}
{7,5,7}
{7,5,6}
{7,5,5}
{7,5,4}
{7,5,3}
{7,5,2}
{7,5,1}
{7,4,8}
{7,4,7}
{7,4,6}
{7,4,5}
{7,4,4}
{7,4,3}
{7,4,2}
{7,4,1}
{7,3,8}
{7,3,7}
{7,3,6}
{7,3,5}
{7,3,4}
{7,3,3}
{7,3,2}
{7,3,1}
{7,2,8}
{7,2,7}
{7,2,6}
{7,2,5}
{7,2,4}
{7,2,3}
{7,2,2}
{7,2,1}
{7,1,8}
{7,1,7}
{7,1,6}
{7,1,5}
{7,1,4}
{7,1,3}
{7,1,2}
{7,1,1}
{6,8,8}
{6,8,7}
{6,8,6}
{6,8,5}
{ect...}
{1,1,1}

任何想法如何获得这种行为？

注意：我不想实际打印{ect...}，为了不在这个问题上添加512行，我只剪出了大约400行。

谢谢：）

Answer 1

我要感谢anishthecoder的响应，真正帮助我缩小范围。基本上，我只需删除index--（如他所说），并添加一个额外的for循环。请参阅下面的代码......

private static int[] updateArray(int[] array){
    for (int index = array.length - 1 ; index >= 0; index--){
        if (array[index] > 1){
            array[index]--;
            return array;
        } else if (array[index] == 1 && index != 0) {
            if (array[index - 1] != 1) {
                array[index - 1]--;
                for (int i = index; i < array.length; i++){
                    array[i] = maxNum;
                }
                return array;
            }
        }
    }

    return array;
}

我确信有更简洁的方法可以做到这一点，我很乐意将答案提供给能够提出更清洁解决方案的任何人。现在这个工作......

再次感谢anishthecoder：）

具有最小/最大数字的数组索引的顺序倒计时

1 个答案: