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Beginner’s Guide to Code Algorithms

62

STEP 21 continued

  Next j

Next i

snapshotc =​ cantbelist

‘ * Step 2 make a list of all the cells that have 2 values

‘ * note: this bit of code is from the love-​locked pair algorithm

For i =​ 1 To 9

  For j =​ 1 To 9

    cantbelistcount(i, j) =​ 0

    For k =​ 1 To 9

      If cantbelist(i, j, k) <> 0 Then

        cantbelistcount(i, j) =​ cantbelistcount(i, j) +​ 1

      End If

    Next k

    If sbox(i, j) =​ ““ And cantbelistcount(i, j) =​ 7 Then

      putnumberpresent(i, j) =​ ““

      For putnumber =​ 1 To 9

        If findincantbelist(putnumber, i, j) =​ 0 Then

          putnumberpresent(i, j) =​ putnumberpresent(i, j) & putnumber

        End If

      Next putnumber

    End If

  Next j

Next i

STEP 22

Next two steps to use each two-​value cell and try out one of the values to see if Set

1 =​ Set 2.

:

‘ * Step 3 & 4 Try the 2 values, find values for empty cells for each, check for keepers

(Set 1 =​ Set 2) and update grid

For i =​ 1 To 9

  For j =​ 1 To 9

    If putnumberpresent(i, j) <> ““ Then

      ‘ build S1

        Cells(i, j) =​ Left(putnumberpresent(i, j), 1)

        sbox(i, j) =​ Cells(i, j)

        Call RefreshCantbelist

        Call fillemptycells

        For k =​ 1 To 9

        For l =​ 1 To 9

          s1(k, l) =​ Cells(k, l)

        Next l

      Next k

        ‘ restore snapshot

        For k =​ 1 To 9

          For l =​ 1 To 9

            Cells(k, l) =​ snapshot(k, l)

            sbox(k, l) =​ snapshot(k, l)

          Next l