using System;

public class Program

{

    public static void Main()

    {   bool [] digit_seen = new bool [10];

        int digit;

        long n=897 ;

​

        while (n > 0) {

        digit = (int)(n % 10); //得到n的尾數，並將long 轉為int

        Console.WriteLine(digit_seen[digit]);

        if (digit_seen[digit]==true)

            break;

        digit_seen[digit] = true;

        n /= 10;//無條件捨去

        } 

        if (n > 0)

         Console.WriteLine("Repeated digit\n");

        else

        Console.WriteLine("No repeated digit\n");

    }

}