Task: Bulls and cows


C++: #include <iostream>
#include <string>
#include <algorithm>
#include <cstdlib>

bool contains_duplicates(std::string s)
{
  std::sort(s.begin(), s.end());
  return std::adjacent_find(s.begin(), s.end()) != s.end();
}

void game()
{
  typedef std::string::size_type index;

  std::string symbols = "0123456789";
  unsigned int const selection_length = 4;

  std::random_shuffle(symbols.begin(), symbols.end());
  std::string selection = symbols.substr(0, selection_length);
  std::string guess;
  while (std::cout << "Your guess? ", std::getline(std::cin, guess))
  {
    if (guess.length() != selection_length
        || guess.find_first_not_of(symbols) != std::string::npos
        || contains_duplicates(guess))
    {
      std::cout << guess << " is not a valid guess!";
      continue;
    }

    unsigned int bulls = 0;
    unsigned int cows = 0;
    for (index i = 0; i != selection_length; ++i)
    {
      index pos = selection.find(guess[i]);
      if (pos == i)
        ++bulls;
      else if (pos != std::string::npos)
        ++cows;
    }
    std::cout << bulls << " bulls, " << cows << " cows.\n";
    if (bulls == selection_length)
    {
      std::cout << "Congratulations! You have won!\n";
      return;
    }
  }
  std::cerr << "Oops! Something went wrong with input, or you've entered end-of-file!\nExiting ...\n";
  std::exit(EXIT_FAILURE);
}

int main()
{
  std::cout << "Welcome to bulls and cows!\nDo you want to play? ";
  std::string answer;
  while (true)
  {
    while (true)
    {
      if (!std::getline(std::cin, answer))
      {
        std::cout << "I can't get an answer. Exiting.\n";
        return EXIT_FAILURE;
      }
      if (answer == "yes" || answer == "Yes" || answer == "y" || answer == "Y")
        break;
      if (answer == "no" || answer == "No" || answer == "n" || answer == "N")
      {
        std::cout << "Ok. Goodbye.\n";
        return EXIT_SUCCESS;
      }
      std::cout << "Please answer yes or no: ";
    }
    game(); 
    std::cout << "Another game? ";
  }
}







VB: Option Explicit

Sub Main_Bulls_and_cows()
Dim strNumber As String, strInput As String, strMsg As String, strTemp As String
Dim boolEnd As Boolean
Dim lngCpt As Long
Dim i As Byte, bytCow As Byte, bytBull As Byte
Const NUMBER_OF_DIGITS As Byte = 4
Const MAX_LOOPS As Byte = 25 

    strNumber = Create_Number(NUMBER_OF_DIGITS)
    Do
        bytBull = 0: bytCow = 0: lngCpt = lngCpt + 1
        If lngCpt > MAX_LOOPS Then strMsg = "Max of loops... Sorry you loose!": Exit Do
        strInput = AskToUser(NUMBER_OF_DIGITS)
        If strInput = "Exit Game" Then strMsg = "User abort": Exit Do
        For i = 1 To Len(strNumber)
            If Mid(strNumber, i, 1) = Mid(strInput, i, 1) Then
                bytBull = bytBull + 1
            ElseIf InStr(strNumber, Mid(strInput, i, 1)) > 0 Then
                bytCow = bytCow + 1
            End If
        Next i
        If bytBull = Len(strNumber) Then
            boolEnd = True: strMsg = "You win in " & lngCpt & " loops!"
        Else
            strTemp = strTemp & vbCrLf & "With : " & strInput & " ,you have : " & bytBull & " bulls," & bytCow & " cows."
            MsgBox strTemp
        End If
    Loop While Not boolEnd
    MsgBox strMsg
End Sub

Function Create_Number(NbDigits As Byte) As String
Dim myColl As New Collection
Dim strTemp As String
Dim bytAlea As Byte

    Randomize
    Do
        bytAlea = Int((Rnd * 9) + 1)
        On Error Resume Next
        myColl.Add CStr(bytAlea), CStr(bytAlea)
        If Err <> 0 Then
            On Error GoTo 0
        Else
            strTemp = strTemp & CStr(bytAlea)
        End If
    Loop While Len(strTemp) < NbDigits
    Create_Number = strTemp
End Function

Function AskToUser(NbDigits As Byte) As String
Dim boolGood As Boolean, strIn As String, i As Byte, NbDiff As Byte

    Do While Not boolGood
        strIn = InputBox("Enter your number (" & NbDigits & " digits)", "Number")
        If StrPtr(strIn) = 0 Then strIn = "Exit Game": Exit Do
        If strIn <> "" Then
            If Len(strIn) = NbDigits Then
                NbDiff = 0
                For i = 1 To Len(strIn)
                    If Len(Replace(strIn, Mid(strIn, i, 1), "")) < NbDigits - 1 Then
                        NbDiff = 1
                        Exit For
                    End If
                Next i
                If NbDiff = 0 Then boolGood = True
            End If
        End If
    Loop
    AskToUser = strIn
End Function