shuffleandsort.java

java程序设计 清华出版社 孙燮华老师编写的程序源代码

//ShuffleAndSort.java, Author Xie-Hua Sun, 2006.07.25
import java.util.*;
           
public class ShuffleAndSort{
  public static void main(String[] args){
    List numbers = new ArrayList(18);
    
    for (int i = 1; i <= 18; i++)
      numbers.add(new Integer(i));
    Collections.shuffle(numbers);
    System.out.println("\nAfter shuffle the list is: ");
    System.out.println(numbers);
    List winningCombination = numbers.subList(0, 6);
    System.out.println("\nSelect the first 6 elements are: ");
    System.out.println(winningCombination);
    Collections.sort(winningCombination);                             //从小到大
    //Collections.sort(winningCombination,Collections.reverseOrder());//从大到小
    System.out.println("\nAfter sort of the first 6 elements, it is: ");
    System.out.println(winningCombination);
  }
}