题解 | #提取不重复的整数#

import java.util.Scanner;

import java.io.*;
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) throws IOException{
        BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
        String str;
        while ((str = bf.readLine()) != null) {
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < str.length(); i++) {
                char c = str.charAt(i);
                sb.append(c);
            }
            String s = sb.reverse().toString();
            int[] res = new int[s.length()];
            for (int i = 0; i < s.length(); i++) {
                int c = s.charAt(i) - '0';
                res[i] = c;
            }
            Arrays.stream(res).distinct().forEach(System.out::print);
        }
    }
}