import java.util.Random;
import java.util.Scanner;


public class TestClass {
  public static void main(String[] args) {
    Random r = new Random();
    Scanner s = new Scanner(System.in);
    StringBuilder sb = new StringBuilder(4);

    int temp =  r.nextInt(9);
    int bulls, cows;
    String guess = null;
    String str;

    while (sb.length()<4)
    {
        str = sb.toString();
        temp = r.nextInt(9);
        if(!str.contains(Integer.toString(temp)))
         {
            sb.append(temp);
         }

      }


    str = sb.toString();
    System.out.println("original number: " + str);
    boolean game = true;
    boolean incorrect = true;
    while (game)
    {
        bulls = 0;
        cows = 0;
        while (incorrect)
        {
            incorrect = false;
            System.out.print("Enter your number: ");
            guess = s.nextLine();
            for (int i = 0; i <4;i++)
            {
                if (i!=guess.lastIndexOf(guess.charAt(i)))
                {
                 incorrect = true;
                }
            }
            if (incorrect)
            {
                System.out.println("Not all digits are unique! Please try again.");
            }
        }

        for (int i = 0; i<4; i++)
        {
            if (guess.charAt(i)==str.charAt(i))
            {
                bulls++;
            }
        }
        if (bulls==4)
        {
            game = false;
        } else
        {
            for (int i = 0; i<4; i++)
            {
                if (str.contains(Character.toString(guess.charAt(i))))
                {
                    cows++;
                }
            }
            cows-=bulls;
            System.out.println("Amount of bulls: " + bulls);
            System.out.println("Amount of cows: " + cows);
            System.out.println("Try again.");
        }

    }
    System.out.println("Congratulations! The number is indeed " + str);

}
}