题解 | #提取不重复的整数#

import java.util.Scanner;
import java.util.*;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
      public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String s ="";
        //List<String> list = new ArrayList<>();
        Set<String> set = new LinkedHashSet<>();
            int a = in.nextInt();
            String str = String.valueOf(a);
            if(!"0".equals(str.substring(str.length()-1))){
                for (int i = str.length()-1;i>=0;i--){
                    String substring = str.substring(i, i + 1);
                    set.add(substring);
                }
            }
        //}
        for (String num : set){
            s+=num;
        }
        System.out.println(s);
    }
}