题解 | #提取不重复的整数#

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        String str = n+"";
        ArrayList<Character> list = new ArrayList<>();
        for(int i = str.length()-1;i >= 0;i--){
            if(list.contains(str.charAt(i))){
                continue;
            }
            list.add(str.charAt(i));
        }
         for(char ch : list){
             System.out.print(ch);
         }
    }
}