题解 | #提取不重复的整数#

import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        Set<Integer> set = new HashSet<>();
        int target = in.nextInt();
        while (target != 0) {
            int element = target % 10;//得到最右边的个位数字
            if (set.add(element)) {//添加成功进set，说明该位数字不重复
                System.out.print(element);
            }
            target = target / 10;//得到除去个位以外的其它数字
        }

    }
}