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 baseNum = in.nextLine();
        String[] split = baseNum.split("");
	    //有序不重复LinkedHashSet
        LinkedHashSet<String> LinkedHashSet = new LinkedHashSet<String>();
        for (int i = split.length - 1; i >= 0; i--) {
            LinkedHashSet.add(split[i]);
        }
        System.out.print(String.join("", LinkedHashSet));

    }
}