Sub AoC2018_D2()
'
'I can't install python on this laptop so we are bludgeoning day 2 with VBA/excel again, going to attempt and avoid the spreadsheet this time

'
Dim Checksum, count2, count3, Limit As Double
Dim Textfile, i, j As Integer

'file IO shit
Dim Filepath As String
Dim InputFile As String
Dim Inputarray() As String
Dim Alphabet As String


'get string shit as string
Filepath = "C:\Users\machad\Desktop\Advent of Code 2018\AoC 2018 D2 input.txt"
Textfile = FreeFile
Open Filepath For Input As Textfile
InputFile = Input(LOF(Textfile), Textfile)

'make string array so I can go through it line by line
Inputarray = Split(InputFile, vbCrLf)
'count elements in array
Limit = UBound(Split(InputFile, vbCrLf))

'cheating lazy me
Alphabet = "abcdefghijklmnopqrstuvwxyz"
Checksum = 0
count2 = 0
count3 = 0

'test for character count duplicates
'I could put the 2 and 3 cound together but I'm lazy so I'm making a seperate nested loop
For i = 0 To Limit
    For j = 1 To 26
        If count_char(Inputarray(i), (Mid(Alphabet, j, 1))) = 2 Then
            count2 = count2 + 1
            Exit For
        End If
    
        Next j
    
    Next i
'test for char count triplicates
For i = 0 To Limit
    For j = 1 To 26
        If count_char(Inputarray(i), (Mid(Alphabet, j, 1))) = 3 Then
            count3 = count3 + 1
            Exit For
        End If
    Next j
Next i

MsgBox ("the count of 2 repeats is " & count2 & " and the count of 3 repeats is " & count3)

Checksum = (count2 * count3)
MsgBox "The Checksum is " & Checksum, , "Advent of Code 2018 D2P1"
Worksheets("sheet1").Cells(1, "A").Value = Checksum
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
'part two, find elements int he list such that if the same letter is removed from the same position,
'the remaining letters match

'note that each string has length of 26 char in my input, but I'll make this dynamic
Dim Stringholder As String
Dim size, k As Integer
Dim answer As String
Dim array25() As String
ReDim Preserve array25(Limit)
size = Len(Inputarray(1))

'testing removing one char and rebuilding a string
'MsgBox Left(Inputarray(j), 1 - 1) & Right(Inputarray(j), (size - 1))
'yup, it works

'outer loop checks each character position for string of length size
For i = 1 To size
    'inner loop creates holder array where each string is size -1, same order as inputarray
    For j = 0 To Limit

        array25(j) = Left(Inputarray(j), i - 1) & Right(Inputarray(j), (size - i))
        'inner most loop is going to run a check for each line's presence twice.. somehow

    Next j
    For k = 0 To Limit
        Stringholder = array25(k)
        array25(k) = ""
        If IsInArray(Stringholder, array25) Then
            answer = Stringholder
            Exit For
            End If
        array25(k) = Stringholder
    Next k
Next i
MsgBox answer
Worksheets("sheet1").Cells(2, "A").Value = answer

End Sub

Function count_char(varinput As String, var As String)

    count_char = (Len(varinput) - (Len(Replace(varinput, var, ""))))
    
End Function
Private Function IsInArray(valToBeFound As Variant, arr As Variant) As Boolean

Dim element As Variant
On Error GoTo IsInArrayError: 'array is empty
    For Each element In arr
        If element = valToBeFound Then
            IsInArray = True
            Exit Function
        End If
    Next element
Exit Function
IsInArrayError:
On Error GoTo 0
IsInArray = False
End Function