Java将二维数组的行排序为升序，将列排序为降序

Question

拜托，有人可以帮助我，我需要按降序对二维数组列进行排序吗？我使用此代码将数组行按升序排序，但现在必须将列按降序排序。

// Initialize array

static int[][] sortArray = new int[7][7];

public static void main(String args[]) {

    //initialize array values with random numbers

    for (int i = 0; i < sortArray.length; i++) {

        for (int j = 0; j < sortArray[i].length; j++) {

            sortArray[i][j] = (int) (Math.random() * 100);

        }

    }

    System.out.println("\n" + "Before sorting");

    displayArray();

    //Print out sorted array

    for (int i = 0; i < sortArray.length; i++) {

        bubbleSort(sortArray[i]);

    }

    System.out.println("\n" + "Array rows in ascending order");

    displayArray();

    //Print out sorted columns of array

    for (int i = 0; i < sortArray.length; i++) {

        sortSort(sortArray[i]);

    }

    System.out.println("\n" + "Array column in descending order");

    displayArray();

}

// Sort rows into ascending order

public static void bubbleSort(int[] numArray) {

    int n = numArray.length;

    int temp = 0;

    for (int i = 0; i < n; i++) {

        for (int j = 1; j < (n - i); j++) {

            if (numArray[j - 1] > numArray[j]) {

                temp = numArray[j - 1];

                numArray[j - 1] = numArray[j];

                numArray[j] = temp;

            }

        }

    }

}

//Sort cols into descending order

public static void sortSort(int[] colArray) {

    int n = colArray.length;

    int temp = 0;

    for (int i = 0; i < n; i++) {

        for (int j = 1; j < (n - i); j++) {

            if (colArray[j - 1] < colArray[j]) {

                temp = colArray[j - 1];

                colArray[j - 1] = colArray[j];

                colArray[j] = temp;

            }

        }

    }

}

Answer 1

int[] colArray = new int[] { 2, 9, 4, 5};int n = colArray.length;int temp = 0;for (int i = 0; i < n; i++) {&nbsp; for (int j = 1; j < (n - i); j++) {&nbsp; &nbsp; &nbsp; if (colArray[j - 1] > colArray[j]) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; temp = colArray[j - 1];&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; colArray[j - 1] = colArray[j];&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; colArray[j] = temp;&nbsp; &nbsp; &nbsp; }&nbsp; }&nbsp;}&nbsp;Arrays.stream(colArray).forEach(data -> System.out.println(data));

Answer 2

只需更换if (colArray[j - 1] < colArray[j]) {...}和：if (colArray[j - 1] > colArray[j]) {...}> 代替 <

Answer 3

首先，你的数组不是 2D :)，只是因为数组的每个元素都有一个像 Arr[0] 这样的数字被调用，并且它的值是例如 5 它并不意味着它的 2D。但是为了将数组按降序排序，您可以使用以下代码：&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; int n = intArray.length;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; int temp = 0;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; for(int i=0; i < n; i++){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; for(int j=1; j < (n-i); j++){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if(intArray[j-1] < intArray[j]){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; //swap the elements!&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; temp = intArray[j-1];&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; intArray[j-1] = intArray[j];&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; intArray[j] = temp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }