主题：排列组合的问题

参考代码

Dim n As Integer = 20
Dim m As Integer = 5
Dim A As Double = 1
For i As Integer = n To n-m+1 Step -1
    output.show(i)
    A = A * i
Next
Dim mm As Double = 1
For i As Integer = m To 1 Step -1
    output.show(i)
    mm = mm * i
Next

dim C as double = A / mm
msgbox(c)