题解 | 提取不重复的整数

public static void ExtractUniqueNumbers() {
        Scanner sc = new Scanner(System.in);
        int a= sc.nextInt();
        Set<Integer> keys = new HashSet<>();
        int res=0;
        while (a!=0){
            int b=a%10;
            if(keys.add(b)){
                res=res*10+b;
            }
            a=a/10;
        }
        System.out.println(res);
    }