题解 | #提取不重复的整数#

import java.util.*;

public class Main{

public static void main(String[] args){
    
    Scanner sc = new Scanner(System.in);
    HashSet<Integer>  hs = new HashSet<>();
    int num = sc.nextInt();
    while(num%10!=0){
        
        if(hs.add(num%10)){
            System.out.print(num%10);
        }
        num = num/10;
        
    }
    

    
}

}