Sub code1()
Dim x1, x2, ti, i, max, pri
i = 1
ti = Timer
max = 1000000
For x1 = 2 To max
pri = True
For x2 = 2 To Sqr(x1)
If x1 Mod x2 = 0 Then
pri = False
Exit For
End If
Next x2
If pri Then
Cells(i, 1) = x1
i = i + 1
End If
Next x1
End Sub
Sub code2()
Dim x1, x2, ti, i, max, pri
i = 2
ti = Timer
max = 1000000
Cells(1, 2) = 2
For x1 = 3 To max Step 2
pri = True
For x2 = 3 To Sqr(x1) + 1 Step 2
If x1 Mod x2 = 0 Then
pri = False
Exit For
End If
Next x2
If pri Then
Cells(i, 2) = x1
i = i + 1
End If
Next x1
End Sub
Sub code1_arr()
Dim x1, x2, ti, i, max, pri
Dim ar(1 To 80000, 1 To 1)
i = 1
ti = Timer
max = 1000000
For x1 = 2 To max
pri = True
For x2 = 2 To Sqr(x1)
If x1 Mod x2 = 0 Then
pri = False
Exit For
End If
Next x2
If pri Then
ar(i, 1) = x1
i = i + 1
End If
Next x1
Cells(1, 3).Resize(UBound(ar), 1).Value = ar
End Sub
Sub code2_arr()
Dim x1, x2, ti, i, max, pri
Dim ar(1 To 80000, 1 To 1)
i = 2
ti = Timer
max = 1000000
ar(1, 1) = 2
For x1 = 3 To max Step 2
pri = True
For x2 = 3 To Sqr(x1) + 1 Step 2
If x1 Mod x2 = 0 Then
pri = False
Exit For
End If
Next x2
If pri Then
ar(i, 1) = x1
i = i + 1
End If
Next x1
Cells(1, 4).Resize(UBound(ar), 1).Value = ar
End Sub
Sub vorschlag()
Dim candidate As Long
Dim max As Long
Dim isPrime As Boolean
Dim i As Long, i2 As Long
Dim sqr_candidate As Double
Dim primes(1 To 80000, 1 To 1) As Long
max = 1000000
i = 1
primes(i, 1) = 2
primes(2, 1) = 3
For candidate = 3 To max Step 2
isPrime = True
i2 = 2
sqr_candidate = Sqr(candidate)
Do Until primes(i2, 1) > sqr_candidate
If candidate Mod primes(i2, 1) = 0 Then
isPrime = False
Exit Do
End If
i2 = i2 + 1
Loop
If isPrime Then
i = i + 1
primes(i, 1) = candidate
End If
Next candidate
Cells(1, 5).Resize(i, 1).Value = primes
End Sub
Sub test_them()
Dim i As Long, t
Const n = 2
Call code1
Call code2
Call code1_arr
Call code2_arr
Call vorschlag
t = Timer
For i = 1 To n
Call code1
Next
Debug.Print "code1: ", Timer - t
t = Timer
For i = 1 To n
Call code1_arr
Next
Debug.Print "code1_arr: ", Timer - t
t = Timer
For i = 1 To n
Call code2
Next
Debug.Print "code2: ", Timer - t
t = Timer
For i = 1 To n
Call code2_arr
Next
Debug.Print "code2_arr: ", Timer - t
t = Timer
For i = 1 To n
Call vorschlag
Next
Debug.Print "vorschlag: ", Timer - t
msgbox "fertig: siehe Direktfenster"
End Sub