题解:使用LinkeHashSet可以保持原来顺序,又可以去重

import java.util.*;
public class Main{
    public static void main(String[] args){
            Scanner sc = new Scanner(System.in);
        while(sc.hasNext()){
            int n = sc.nextInt();
            int[] a = new int[n];
           for(int i = 0; i < n; i++){
               a[i] = sc.nextInt();
            }
             sort(a);
        } 
    }
    
    public static void sort(int[] a){
    Set<Integer> set = new LinkedHashSet<>();
         for(int j = 0; j < a.length; j++){
             set.add(a[j]);
            }
        for(Integer i : set){
             System.out.print(i + " ");
        }
    }
}