Imports System

Public Module Module1

    Public Sub Main()

        Dim n As New Random

        Dim number As String = n.Next(1, 10)

        Dim digit, cows, bulls, guessCounter As Integer

        Dim check, valid As Boolean

        Dim guess As String

        For i = 1 To 3

            Do

                check = False

                digit = n.Next(0, 10)

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                If number.ToString.Contains(digit) Then

                    check = True

                End If

​

            Loop While check = True

            number = number * 10 + digit

        Next

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        Console.WriteLine(number)

​

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        Do

            cows = 0

            bulls = 0

            Do

                valid = True

                Console.Write("Enter your guess : ")

                guess = Console.ReadLine

                guessCounter = guessCounter + 1

                If valid = True Then

                        For j = 0 To 3

                            For k = 0 To 3

                                If j <> k Then

                                    If guess.Chars(j) = guess.Chars(k) Then

                                        valid = False

                                    End If

                                End If

                            Next

                        Next

                    If guess < 1023 Or guess > 9876 Then

                        valid = False

                    End If

                End If

                If valid = False Then

                    Console.WriteLine("Invalid Guess")

                End If

            Loop Until valid = True

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            For l = 0 To 3

                If guess(l) = number(l) 

                   bulls = bulls + 1 

                End If 

                For m = 0 To 3 

                    If m <> l 

                        If guess(m) = number(l) 

                            cows = cows + 1 

                        End If 

                    End If 

                Next 

            Next

            If bulls <> 4 

                Console.WriteLine("Cows: " & cows & "          Bulls: " & bulls & "          Guesses: " & guessCounter) 

            End If 

        Loop Until bulls = 4

        Console.WriteLine("Guess correctly in " & guessCounter & " tries.")

    End Sub

End Module

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