import java.util.Scanner; import java.util.TreeSet; import java.util.Set; import java.util.Iterator; public class Main { public static void main(String[] args) { Scanner in = new Scanner(System.in); int a = in.nextInt(); Set set = new TreeSet();//用treeset去重并且升序排序,需要导包 for(int i =1; i<=a; i++){ se...