题解 | 提取不重复的整数

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        Set<Integer> set = new HashSet<>();
        while(n != 0){
            int mod = n%10;
            if(!set.contains(mod)){
                set.add(mod);
                System.out.print(mod);
            }
            n /= 10;
        }
    }
}