Java 实例 升序和降序的冒泡排序

在本教程中，我们将看到如何在按升序和降序进行排序。使用冒泡排序算法降序排序。

冒泡排序程序，按升序排序

import java.util.Scanner;

class BubbleSortExample {
  public static void main(String []args) {
    int num, i, j, temp;
    Scanner input = new Scanner(System.in);

    System.out.println("Enter the number of integers to sort:");
    num = input.nextInt();

    int array[] = new int[num];

    System.out.println("Enter " + num + " integers: ");

    for (i = 0; i < num; i++) 
      array[i] = input.nextInt();

    for (i = 0; i < ( num - 1 ); i++) {
      for (j = 0; j < num - i - 1; j++) {
        if (array[j] > array[j+1]) 
        {
           temp = array[j];
           array[j] = array[j+1];
           array[j+1] = temp;
        }
      }
    }

    System.out.println("Sorted list of integers:");

    for (i = 0; i < num; i++) 
      System.out.println(array[i]);
  }
}

输出：

Enter the number of integers to sort:
6
Enter 6 integers: 
12
6
78
9
45
08
Sorted list of integers:
6
8
9
12
45
78

冒泡排序程序，按降序排序

为了按降序排序，我们只需要将上面程序中的数组array的逻辑从array[j] > array[j+1]更改为array[j] < array[j+1]。完整代码如下：

import java.util.Scanner;

class BubbleSortExample {
  public static void main(String []args) {
    int num, i, j, temp;
    Scanner input = new Scanner(System.in);

    System.out.println("Enter the number of integers to sort:");
    num = input.nextInt();

    int array[] = new int[num];

    System.out.println("Enter " + num + " integers: ");

    for (i = 0; i < num; i++) 
      array[i] = input.nextInt();

    for (i = 0; i < ( num - 1 ); i++) {
      for (j = 0; j < num - i - 1; j++) {
        if (array[j] < array[j+1]) 
        {
          temp = array[j];
          array[j] = array[j+1];
          array[j+1] = temp;
        }
      }
    }

    System.out.println("Sorted list of integers:");

    for (i = 0; i < num; i++) 
      System.out.println(array[i]);
  } 
}

输出：

Enter the number of integers to sort:
6
Enter 6 integers: 
89
12
45
9
56
102
Sorted list of integers:
102
89
56
45
12
9