平平无奇
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
while (sc.hasNext()) {
int number = sc.nextInt();
Set<Integer> numSet = new HashSet<>(); // set to record existed numbers
int currentNum, result = 0;
while (number > 0) {
currentNum = number % 10;
number /= 10;
// check num duplicate
if (numSet.contains(currentNum)) {
continue; // skip current round
}
numSet.add(currentNum); // upadte set
result = result * 10 + currentNum;
}
System.out.println(result);
}
}
}