In the current article, I will present the way to calculate the number of chars in a string with VBA. The inspiration came from the entry exam forHackBulgaria Programming 101v3. The tasks were given some months ago, so I assume it is OK to publish my solutions for them.

The previous task is resolved with VBA here.

So, this is the problem, as explained by the team of HackBulgaria:

AB Check

You have the implement a function, with the following signature: ABCheck(str).

The argument str is of type string.

The function should return true if the characters a and b are separated by exactly 3 places anywhere in the string at least once.

Otherwise return false

For example – "lane borrowed" would result in true because there is exactly three characters between a and b. .

You can use any language you know.

Examples:

What I did? I have decided to look at two cases – case one, is when we have first the “a” and four positions later the “b” and case two, is when we have first the “b”.

How I did it? With one for-loop and two checks for A and for B. Probably in Python the solution can be in less than 10 lines, but this one is in Excel 😛

Here is how it looks like:

Here comes the code:

Option Explicit
Option Compare Text

Public Function ABCheck(sInput As String) As Boolean

    Dim strArray() As String

    Dim sA As String
    Dim sB As String

    Dim lCount As Long

    lCount = Len(sInput)
    ReDim strArray(lCount - 1)
    
    If lCount < 5 Then Exit Function
    
    sA = "a"
    sB = "b"

    For lCount = 0 To lCount - 1
        strArray(lCount) = Mid(sInput, lCount + 1, 1)

        If CStr(strArray(lCount)) = sA Then
            If lCount + 3 <= (Len(sInput) - 1) Then
            strArray(lCount + 4) = Mid(sInput, lCount + 5, 1)
                Debug.Print strArray(lCount + 4)
                Debug.Print Mid(sInput, lCount + 5, 1)
                
                If CStr(strArray(lCount + 4)) = sB Then
                    ABCheck = True
                    Exit Function
                    
                End If
            End If
            
        ElseIf CStr(strArray(lCount)) = sB Then
        
            If lCount + 3 <= (Len(sInput) - 1) Then
            strArray(lCount + 4) = Mid(sInput, lCount + 5, 1)
                Debug.Print strArray(lCount + 4)
                Debug.Print Mid(sInput, lCount + 5, 1)

                If CStr(strArray(lCount + 4)) = sA Then
                    ABCheck = True
                    Exit Function
                End If
            End If
        End If
        
    Next lCount
End Function

Enjoy it! 🙂