算法训练 明明的随机数

import java.util.Arrays;
import java.util.Scanner;
public class Main {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner  sc=new Scanner(System.in);
        while(sc.hasNext()){
        int n=sc.nextInt();
        int b[]=new int[n];
        for(int i=0;i<n;i++){
            b[i]=sc.nextInt();
        }
        Arrays.sort(b);
        for(int i=0;i<n;i++){
            for(int j=i+1;j<n;j++){
                if(b[i]==b[j] && b[i]!=-1)
                    b[j]=-1;
            }
        }
        int sum=0;
        for(int i=0;i<n;i++){
            if(b[i]!=-1){
                sum++;
            }
        }
        System.out.println(sum);
        for(int i=0;i<n;i++){
            if(b[i]!=-1)
                System.out.print(b[i]+" ");
        }
        
        }
    }

}