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' Generates Magic Squares of order 3 for Prime Numbers

' Tested with Office 2007 under Windows 7

Sub Priem3()

Dim a1(72), a(9), b1(355), b(355), c(9)

y = MsgBox("Locked", vbCritical, "Routine Priem3")
End
    
    n1 = 0: n9 = 0: n10 = 0: k1 = 1: k2 = 1
    m1 = 1: m2 = 72
    Smin = 26: Smax = 987

'   Read Prime Numbers From sheet "Priem"
    
    i3 = 0: k10 = 3: k20 = 0
    For i1 = 1 To 8
        For i2 = 2 To 18 Step 2
            i3 = i3 + 1
            a1(i3) = Sheets("Priem").Cells(k10 + i1, k20 + i2).Value
        Next i2
    Next i1

    For i1 = 1 To m2
        b1(a1(i1)) = a1(i1)
    Next i1

'   Generate Squares
    
    Sheets("Klad1").Select
    
    t1 = Timer

For j10 = Smin To Smax

x = j10 / 3: If CInt(x) <> x Then GoTo 10

s1 = j10: Cells(k1, 1).Value = j10

For j9 = m1 To m2                                                     'a(9)
If b(a1(j9)) = 0 Then b(a1(j9)) = a1(j9): c(9) = a1(j9) Else GoTo 160
a(9) = a1(j9)

For j8 = m1 To m2                                                     'a(8)
If b(a1(j8)) = 0 Then b(a1(j8)) = a1(j8): c(8) = a1(j8) Else GoTo 120
a(8) = a1(j8)

    a(7) = s1 - a(8) - a(9):
    If a(7) < a1(m1) Or a(7) > a1(m2) Then GoTo 110:
    If b1(a(7)) = 0 Then GoTo 110
    
    a(6) = 4 * s1 / 3 - a(8) - 2 * a(9):
    If a(6) < a1(m1) Or a(6) > a1(m2) Then GoTo 110:
    If b1(a(6)) = 0 Then GoTo 110
    
    a(5) = s1 / 3:
    If a(5) < a1(m1) Or a(5) > a1(m2) Then GoTo 110:
    If b1(a(5)) = 0 Then GoTo 110
    
    a(4) = -2 * s1 / 3 + 1 * a(8) + 2 * a(9):
    If a(4) < a1(m1) Or a(4) > a1(m2) Then GoTo 110:
    If b1(a(4)) = 0 Then GoTo 110
    
    a(3) = -s1 / 3 + 1 * a(8) + 1 * a(9):
    If a(3) < a1(m1) Or a(3) > a1(m2) Then GoTo 110:
    If b1(a(3)) = 0 Then GoTo 110
    
    a(2) = 2 * s1 / 3 - a(8):
    If a(2) < a1(m1) Or a(2) > a1(m2) Then GoTo 110:
    If b1(a(2)) = 0 Then GoTo 110
    
    a(1) = 2 * s1 / 3 - a(9):
    If a(1) < a1(m1) Or a(1) > a1(m2) Then GoTo 110:
    If b1(a(1)) = 0 Then GoTo 110

'                         Exclude solutions with identical numbers

                          GoSub 800: If fl1 = 0 Then GoTo 110
                          n10 = n10 + 1
'                         n9 = n9 + 1: GoSub 640 'Print results (selected numbers)
                          n9 = n9 + 1: GoSub 650 'Print results (squares)
   
110 b(c(8)) = 0: c(8) = 0
120 Next j8
    
    b(c(9)) = 0: c(9) = 0
160 Next j9
    n10 = 0
10  Next j10

   t2 = Timer
    
   t10 = Str(t2 - t1) + " sec., " + Str(n9) + " Solutions"
   y = MsgBox(t10, 0, "Routine Priem3")

End

'   Print results (selected numbers)

640 Cells(n9, 9).Select
    For i1 = 1 To 9
        Cells(n9, i1).Value = a(i1)
    Next i1
    Return

'   Print results (squares)

650 n1 = n1 + 1
    If n1 = 5 Then
        n1 = 1: k1 = k1 + 4: k2 = 1
    Else
        If n9 > 1 Then k2 = k2 + 4
    End If
    
    Cells(k1, k2 + 1).Select
    Cells(k1, k2 + 1).Font.Color = -4165632
    Cells(k1, k2 + 1).Value = n10
    
    i3 = 0
    For i1 = 1 To 3
        For i2 = 1 To 3
            i3 = i3 + 1
            Cells(k1 + i1, k2 + i2).Value = a(i3)
        Next i2
    Next i1
    Return

'   Exclude solutions with identical numbers

800 fl1 = 1
    For j1 = 1 To 9
       a2 = a(j1)
       For j2 = (1 + j1) To 9
           If a2 = a(j2) Then fl1 = 0: Return
       Next j2
    Next j1
    Return

End Sub

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