Anonymous user
Permutations: Difference between revisions
VBA
(adding maxima, trnalation of Ada) |
(VBA) |
||
Line 2,054:
<3,1,2>,
<3,2,1>></pre>
=={{header|VBA}}==
Based on the Pascal version above.
<lang VBA>
Public Sub Permute(n As Integer, Optional printem As Boolean = True)
'generate, count and print (if printem is not false) all permutations of first n integers
Dim P() As Integer
Dim count As Long
dim Last as boolean
Dim t, i, j, k As Integer
If n <= 1 Then
Debug.Print "give a number greater than 1!"
Exit Sub
End If
'initialize
ReDim P(n)
For i = 1 To n: P(i) = i: Next
count = 0
Last = False
Do While Not Last
'print?
If printem Then
For t = 1 To n: Debug.Print P(t);: Next
Debug.Print
End If
count = count + 1
Last = True
i = n - 1
Do While i > 0
If P(i) < P(i + 1) Then
Last = False
Exit Do
End If
i = i - 1
Loop
If Not Last Then
j = i + 1
k = n
While j < k
' swap p(j) and p(k)
t = P(j)
P(j) = P(k)
P(k) = t
j = j + 1
k = k - 1
Wend
j = n
While P(j) > P(i)
j = j - 1
Wend
j = j + 1
'swap p(i) and p(j)
t = P(i)
P(i) = P(j)
P(j) = t
End If 'not last
Loop 'while not last
Debug.Print "Number of permutations: "; count
End Sub
</lang>
Sample dialogue:
<pre>
permute 1
give a number greater than 1!
permute 2
1 2
2 1
Number of permutations: 2
permute 4
1 2 3 4
1 2 4 3
1 3 2 4
1 3 4 2
1 4 2 3
1 4 3 2
2 1 3 4
2 1 4 3
2 3 1 4
2 3 4 1
2 4 1 3
2 4 3 1
3 1 2 4
3 1 4 2
3 2 1 4
3 2 4 1
3 4 1 2
3 4 2 1
4 1 2 3
4 1 3 2
4 2 1 3
4 2 3 1
4 3 1 2
4 3 2 1
Number of permutations: 24
permute 10,False
Number of permutations: 3628800
</pre>
| |||