Java 如何对TreeSet进行降序排序

给定一个Java中的TreeSet，任务是将TreeSet中的元素按降序（descreasing order）排序。

例子

Input : Set: [2, 3, 5, 7, 10, 20]
Output : Set: [20, 10, 7, 5, 3, 2]

Input : Set: [computer, for, geeks, hello]
Output : Set: [hello, geeks, for, computer]

建议。请先在{IDE}上尝试你的方法，然后再继续解决

方法：

为了使TreeSet元素按递减顺序排列，只需使用 descendingSet() 方法，该方法用于以反向顺序改变TreeSet的顺序

下面是上述方法的实现。

// Java Program to print TreeSet in reverse Order
import java.util.TreeSet;
 
public class TreeSetDescending
{
 
    public static void main(String[] args)
    {
        // Declare a treeset
        TreeSet<Object> ints = new TreeSet<Object>();
        ints.add(2);
        ints.add(20);
        ints.add(10);
        ints.add(5);
        ints.add(7);
        ints.add(3);
 
        // Initialize treeset with
        // predefined set in reverse order
        // using descendingSet()
        TreeSet<Object> intsReverse =
            (TreeSet<Object>)ints.descendingSet();
 
        // Print the set
        System.out.println("Without descendingSet(): " +
                                                 ints);
        System.out.println("With descendingSet(): " +
                                           intsReverse);
    }
}

输出

Without descendingSet(): [2, 3, 5, 7, 10, 20]
With descendingSet(): [20, 10, 7, 5, 3, 2]