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);
        String s=sc.nextLine();
        char[] ch=s.toCharArray();
        StringBuffer result=new StringBuffer("");
        for(int i=s.length()-1;i>=0;i--){
            if(!result.toString().contains(s.substring(i,i+1))){
                result.append(s.charAt(i));
            }
        }
        System.out.println(result.toString());
    }
}