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 = String.valueOf(n);
   
        List<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));
        }
        StringBuffer sb = new StringBuffer();
        for (char a:list
             ) {
  
            sb.append(a);
        }
        System.out.println(Integer.valueOf(sb.toString()));
    }
}