0

我需要获得所有可能组合的列表，而不是排列。

为了确保我有正确的名字，123 和 321 对我来说是同一个东西，应该只列出一次。

下面的代码可以满足我的需要，但我无法将其转换为 MS Access vba。

对不起，我知道这是基本的，它已经被问了一百万次，但我找不到任何适合我的 MS Access。

 Sub test_print_nCr()
      print_nCr 7, 3, Range("A1")
    End Sub

2.

Public Function print_nCr(n As Integer, r As Integer, p As Range)

  c = 1
  internal_print_nCr n, r, p, 1, 1
End Function

3.

Public Function internal_print_nCr(n As Integer, r As Integer, ByVal p As Range, Optional i As Integer, Optional l As Integer) As Integer

  ' n is the number of items we are choosing from
  ' r is the number of items to choose
  ' p is the upper corner of the output range
  ' i is the minimum item we are allowed to pick
  ' l is how many levels we are in to the choosing
  ' c is the complete set we are working on

  If n < 1 Or r > n Or r < 0 Then Err.Raise 1
  If i < 1 Then i = 1
  If l < 1 Then l = 1
  If c < 1 Then c = 1
  If r = 0 Then
    p = 1
    Exit Function
  End If

  Dim x As Integer
  Dim y As Integer

  For x = i To n - r + 1
    If r = 1 Then
      If c > 1 Then
        For y = 0 To l - 2
          If p.Offset(c - 1, y) = "" Then p.Offset(c - 1, y) = p.Offset(c - 2, y)
        Next
      End If
      p.Offset(c - 1, l - 1) = x
      c = c + 1
    Else
      p.Offset(c - 1, l - 1) = x
      internal_print_nCr n, r - 1, p, x + 1, l + 1
    End If
  Next

End Function

再次感谢你

4

2 回答 2

0

I am not sure if this is the best method to do this, but I would use a kind of binary representation. For instance, consider the word "boy" with the number of letters n=3. This word has three letters, so you can use something like this:

001 = y, 010 = o, 011 = oy, 100 = b, 101 = by, 110 = bo, 111 = boy.

The left side can be done with a loop from i=1 to power(2,n)-1 and transforming i to a number in the binary basis. So, the only thing you have to do is to use the non null positions to build your combinations.

Probably there is something more interesting than this in Knuth.

于 2013-03-22T01:19:31.680 回答
0

我在这里找到了这段代码，它给了我我需要的东西。您只需要创建一个包含 1-100 数字的表格。以下链接中的说明

在此处输入链接描述

谢谢大家

Public Sub buildquery(strN As String, K As Integer)
    Dim qd As DAO.QueryDef
    Dim intI As Integer
    Dim strsql As String
    Dim strSelect As String
    Dim strFrom As String
    Dim strWhere As String

    Set qd = CurrentDb.QueryDefs("QN")
    qd.sql = "SELECT N FROM tblN WHERE N IN (" & strN & ")"
    Set qd = Nothing
    strSelect = "SELECT QN.N "
    strFrom = "FROM QN "
    strWhere = "WHERE QN_1.N > QN.N "
    For intI = 1 To K - 1
        strSelect = strSelect & ", QN_" & intI & ".N AS N" & intI & " "
        strFrom = strFrom & ", QN AS QN_" & intI & " "
        If intI < K - 1 Then
            strWhere = strWhere & " AND QN_" & intI + 1 & ".N > QN_" & intI & ".N "
        End If
    Next
    strsql = strSelect & " INTO tblCombinations " & strFrom & strWhere
    DoCmd.SetWarnings False
    DoCmd.RunSQL strsql
    DoCmd.SetWarnings True
End Sub

然后测试

Public Sub testbuildquery()
  buildquery "1,2,3,4,5,6,7", 3
End Sub
于 2013-03-22T05:45:48.043 回答