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Explore Your Deductive Logic—Sudoku

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STEP 22 Continued (fill emptycells)

  For i =​ 1 To 9

    If sbox(i, j) =​ putnumber Then numberfound =​ 1

  Next i

 

 

      If numberfound =​ 0 Then

        notahomecount =​ 0

        For i =​ 1 To 9

          notahome =​ 0

          If sbox(i, j) <> ““ Then notahome =​ 1

          For k =​ 1 To 9

            If cantbelist(i, j, k) =​ putnumber Then notahome =​ 1

          Next k

          If notahome =​ 1 Then

            notahomecount =​ notahomecount +​ 1

          Else

            home =​ i

            End If

          Next i

          If notahomecount =​ 8 Then

            sbox(home, j) =​ putnumber

            Call updatecantbelist(putnumber, home, j)

            Cells(home, j) =​ sbox(home, j)

          End If

        End If

      Next j

       

‘ now check all cells in the 3x3 boxes for all numbers 1-​9 (putnumber)

‘ if the number is invalid in 8 of the nine cells in the same 3x3 box, then the number

‘ must belong to the ninth cell (empty, of course)

For i =​ 1 To 3

  For j =​ 1 To 3

    For k =​ 1 To 3

      n =​ Int((i -​ 1) /​ 3) * 3 +​ k

      For l =​ 1 To 3

        p =​ Int((j -​ 1) /​ 3) * 3 +​ l

        numberfound =​ 0

        If sbox(n, p) =​ putnumber Then numberfound =​ 1

      Next l

    Next k

   

  If numberfound =​ 0 Then

    notahomecount =​ 0

    For k =​ 1 To 3

      n =​ Int((i -​ 1) /​ 3) * 3 +​ k

      For l =​ 1 To 3

        p =​ Int((j -​ 1) /​ 3) * 3 +​ l

        notahome =​ 0